---
title: "A heat sink, and an energy balance closed to 99.7%"
url: "https://tryreynolds.com/studies/finned-heat-sink"
description: "Aluminium conducting into air, solved as one coupled problem on 8,320 cells. The agent audited the run against the first law of thermodynamics and kept solving until the books balanced."
---

**[Reynolds](https://tryreynolds.com)** is agentic CFD, built by
**[InviscidAI](https://inviscidai.com)** and backed by Y Combinator, Winter 2026 batch.
The agent is open source under the MIT licence at
[github.com/InviscidAI/OpenReynolds](https://github.com/InviscidAI/OpenReynolds).
Using it requires no OpenFOAM knowledge.

This is the agent-readable Markdown twin of https://tryreynolds.com/studies/finned-heat-sink. It lives at https://tryreynolds.com/studies/finned-heat-sink.md, and
[tryreynolds.com/llms.txt](https://tryreynolds.com/llms.txt) indexes every one of them.

# A heat sink, and an energy balance closed to 99.7%

Aluminium conducting into air, solved as one coupled problem on 8,320 cells. The agent audited the run against the first law of thermodynamics and kept solving until the books balanced.

RUN 04APPLIEDELECTRONICS COOLINGMAY 202620260507-080356-73d0

- **Asked**: “Electronics cooling: a finned aluminium heat sink on a 15 W CPU with 2 m/s air blowing across the fins. Give me the sink base temperature and the overall thermal resistance in K/W.”
- **Run**: chtMultiRegionSimpleFoam · 8,320 cells · single core · 12 minutes
- **Result**: Energy balance closed to 99.7%
- **Model**: Conjugate heat transfer: aluminium conduction and air convection solved as one coupled system
- **Reduction**: A symmetric unit cell, one fin plus two half channels, at 8,320 cells instead of the full array
- **Energy balance**: 99.7% closed between heat in at the base and enthalpy out in the air
- **Steadiness**: Base temperature drifting by less than 0.0001 K over the final iterations

![Temperature through an aluminium heat-sink fin and the air beside it](https://tryreynolds.com/assets/hs-temp-GfzCYTQR.png)

Figure 1 The hot base, and the gradient up the fin into the cooling air.

## Choosing the smallest sufficient problem

No geometry was supplied, so Reynolds specified a plausible one and said exactly what it had assumed: a 40 × 40 × 3 mm aluminium base with eight straight fins, 1.5 mm thick and 20 mm tall at 5 mm pitch, with air entering along the fin length at 2 m/s and 25 °C.

Then it did the thing that separates a fast answer from a slow one. A plate-fin array is periodic, so rather than meshing eight fins it meshed one: a single fin with half a channel on each side and symmetry planes down the middle of those channels. That is the standard reduction for this geometry, and it turns a problem of tens of thousands of cells into one of 8,320 while solving exactly the same physics.

This is a conjugate problem, which means the temperature field in the metal and the temperature field in the air are solved together, coupled at the interface, rather than one being imposed as a boundary condition on the other. The channel Reynolds number came out around 417, comfortably laminar, so no turbulence model was needed and none was used.

## Auditing the answer against the first law

Momentum and pressure converged in about 1,500 iterations and the run looked finished. Reynolds tested it against thermodynamics instead of accepting that: it compared the heat going in at the base with the enthalpy the air was carrying out.

At 1,500 iterations that balance was 38% closed. Nearly two thirds of the heat entering the sink was, as far as the solution was concerned, going nowhere. A thermal answer read off at that point would have been badly wrong while looking entirely settled, because the flow field had converged and the temperature field simply had not caught up: heat diffusing through aluminium equilibrates on a much longer timescale than the air takes to establish its flow pattern.

So it kept going, to 80,000 iterations, which on a mesh this small is twelve minutes. The energy balance closed to 99.7% and the base temperature settled to within 0.0001 K. Only then did it report a number.

## Why the check is the story

Residual convergence answers a numerical question: are the equations being satisfied to a given tolerance. An energy balance answers a physical one: is the heat going somewhere real. They are not the same question, and in a conjugate problem they converge on completely different timescales.

A tool that watches only the first will hand you a thermal resistance that is confidently and invisibly wrong. This run went looking for the second, found it open, and closed it.

![A cross-section of the heat sink mesh showing the solid aluminium region and two air channels](https://tryreynolds.com/assets/hs-mesh-D1Jm4rSY.png)

Figure 2 One fin and its two channels: solid aluminium and air, meshed as two coupled regions.

![Velocity field in the air channel between fins](https://tryreynolds.com/assets/hs-flow-BaiDI43o.png)

Figure 3 Boundary layers developing on the fin walls down the channel.

## The whole session, exactly as it happened.

One prompt in, and everything the agent said and ran on the way to the answer. Open a step to see the command it sent and what came back. Nothing here is rewritten.

35 messages, 148 tool calls

### you

Electronics cooling: a finned aluminium heat sink on a 15 W CPU with 2 m/s air blowing across the fins. Give me the sink base temperature and the overall thermal resistance in K/W.

### tool: bash

`ls /work | head -30; echo ---; ls /work/.toolbox; echo ---; cat /work/.toolbox...` exit 0

**input**

```
{
  "cmd": "ls /work | head -30; echo ---; ls /work/.toolbox; echo ---; cat /work/.toolbox/notes/*.md 2>/dev/null | head -100"
}
```

### tool: bash

`sed -n '1,80p' /work/.toolbox/geometry_view.py; echo ===RENDER===; sed -n '1,1...` exit 0

**input**

```
{
  "cmd": "sed -n '1,80p' /work/.toolbox/geometry_view.py; echo ===RENDER===; sed -n '1,120p' /work/.toolbox/render.py | head -150; echo ===CASEGEN===; sed -n '1,60p' /work/.toolbox/case_gen.py"
}
```

**output**

```
exit_code: 0

#!/usr/bin/env python3
"""Surface geometry -> pictures of it, plus the numbers that describe it.

Meshing decisions are made against geometry nobody has looked at, and a surface that
is 1000x too large, inside-out, or full of holes looks exactly like a good one from
the shell. This draws it -- four fixed views, every facet edge visible -- and prints
what is measurable about it. It attaches no verdicts: whether 40 open edges matter
depends on where they are and what you are about to run.

    python3 geometry_view.py wing.stl
    python3 geometry_view.py constant/triSurface/            # every surface in a dir
    python3 geometry_view.py a.stl b.stl --per-part --out /work/case/renders
    python3 geometry_view.py wing.stl --check               # numbers only, no render

Reads anything VTK reads: .stl, .obj, .ply, .vtk, .vtp, .vtu.
"""

from __future__ import annotations

import argparse
import sys
from pathlib import Path

import numpy as np
import pyvista as pv

pv.OFF_SCREEN = True

SUFFIXES = (".stl", ".obj", ".ply", ".vtk", ".vtp", ".vtu")

VIEWS = (("iso", "isometric"), ("xy", "+z looking down"), ("xz", "+y"), ("yz", "+x"))

EDGE_BUDGET = 200_000
"""Above this many faces, every-edge rendering draws mud. Decimate and say so."""

COLOURS = (
    "lightsteelblue", "salmon", "darkseagreen", "khaki", "plum",
    "lightcoral", "paleturquoise", "sandybrown", "thistl
```

### tool: bash

`grep -ril "heatsink\|heat sink\|chtMultiRegion" /work/2026* 2>/dev/null | head...` exit -1

**input**

```
{
  "cmd": "grep -ril \"heatsink\\|heat sink\\|chtMultiRegion\" /work/2026* 2>/dev/null | head -20"
}
```

**output**

```
exit_code: -1
[took 123s]
[exit_code -1 means no exit status was reported, which is what happens when a command outruns its timeout_s (this one ran with 120s). job_start has no time limit.]
```

### tool: bash

`grep -ril "heatsink\|heat sink\|chtMultiRegion" /work/2026* 2>/dev/null | head...`

**input**

```
{
  "cmd": "grep -ril \"heatsink\\|heat sink\\|chtMultiRegion\" /work/2026* 2>/dev/null | head -20",
  "timeout_s": 280
}
```

**output**

```
bad_response (303): the service answered 303 with a body that is not JSON (the body was empty)
```

### tool: bash

`timeout 60 grep -rl "chtMultiRegion" /work/2026* --include="*" 2>/dev/null | h...` exit 0

**input**

```
{
  "cmd": "timeout 60 grep -rl \"chtMultiRegion\" /work/2026* --include=\"*\" 2>/dev/null | head"
}
```

**output**

```
exit_code: 0
[took 44s]
```

### tool: bash

`grep -rl "cellZone" $FOAM_TUTORIALS --include=blockMeshDict | head; echo ---; ...` exit 0

**input**

```
{
  "cmd": "grep -rl \"cellZone\" $FOAM_TUTORIALS --include=blockMeshDict | head; echo ---; find $FOAM_TUTORIALS -iname \"*heater*\" -o -iname \"*multiRegion*\" | grep -i cht | head -20"
}
```

**output**

```
exit_code: 0

---
/usr/lib/openfoam/openfoam2512/tutorials/basic/chtMultiRegionFoam
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/externalCoupledHeater
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/externalCoupledHeater/constant/heater
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/externalCoupledHeater/system/heater
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/multiRegionHeater
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/multiRegionHeater/constant/heater
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/multiRegionHeater/system/heater
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/snappyMultiRegionHeater
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/snappyMultiRegionHeater/constant/heater
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/snappyMultiRegionHeater/system/heater
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/snappyMultiRegionHeaterImplicit
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/snappyMultiRegionHeaterImplicit/constant/heater
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/snapp
```

### tool: bash

`cd /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleF...` exit 1

**input**

```
{
  "cmd": "cd /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/multiRegionHeater; find . -maxdepth 2; echo ---blockMeshDict---; cat system/blockMeshDict 2>/dev/null | head -80; echo ---topoSetDict---; cat system/topoSetDict 2>/dev/null; echo ---Allrun---; cat Allrun"
}
```

**output**

```
exit_code: 1

bash: line 4: cd: /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/multiRegionHeater: No such file or directory
.
---blockMeshDict---
---topoSetDict---
---Allrun---
cat: Allrun: No such file or directory
```

### tool: bash

`find /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpl...` exit 0

**input**

```
{
  "cmd": "find /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam -maxdepth 1"
}
```

**output**

```
exit_code: 0

/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/cpuCabinet
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/externalCoupledHeater
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/heatExchanger
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/jouleHeatingSolid
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/multiRegionHeaterRadiation
```

### tool: bash

`cd /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleF...` exit 0

**input**

```
{
  "cmd": "cd /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/cpuCabinet; find . -maxdepth 3; echo ---Allrun---; cat Allrun*"
}
```

**output**

```
exit_code: 0

.
./0.orig
./0.orig/domain0
./0.orig/domain0/T
./0.orig/domain0/U
./0.orig/domain0/alphat
./0.orig/domain0/epsilon
./0.orig/domain0/k
./0.orig/domain0/nut
./0.orig/domain0/p
./0.orig/domain0/p_rgh
./0.orig/v_CPU
./0.orig/v_CPU/T
./0.orig/v_CPU/p
./0.orig/v_fins
./0.orig/v_fins/T
./0.orig/v_fins/p
./Allclean
./Allrun
./Allrun.pre
./constant
./constant/domain0
./constant/domain0/MRFProperties
./constant/domain0/thermophysicalProperties
./constant/domain0/turbulenceProperties
./constant/g
./constant/regionProperties
./constant/v_CPU
./constant/v_CPU/thermophysicalProperties
./constant/v_fins
./constant/v_fins/thermophysicalProperties
./system
./system/blockMeshDict
./system/controlDict
./system/createBafflesDict
./system/decomposeParDict
./system/domain0
./system/domain0/decomposeParDict
./system/domain0/fvSchemes
./system/domain0/fvSolution
./system/domain0/topoSetDict
./system/fvSchemes
./system/fvSolution
./system/meshQualityDict
./system/probes
./system/snappyHexMeshDict
./system/surfaceFeatureExtractDict
./system/topoSetDict.f1
./system/v_CPU
./system/v_CPU/decomposeParDict
./system/v_CPU/fvOptions
./system/v_CPU/fvSchemes
./system/v_CPU/fvSolution
./system/v_fins
./system/v_fins/decomposeParDict
./system/v_fins/fvSchemes
./system/v_fins/fvSolution
---Allrun---
#!/bin/sh
cd "${0%/*}" || exit                                # Run from this directory
. ${WM_PROJECT
```

### tool: bash

`cd /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleF...` exit 0

**input**

```
{
  "cmd": "cd /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/cpuCabinet\necho ---regionProperties---; cat constant/regionProperties\necho ---blockMeshDict---; cat system/blockMeshDict\necho ---snappyHexMeshDict---; sed -n '1,200p' system/snappyHexMeshDict"
}
```

**output**

```
exit_code: 0

---regionProperties---
/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v2512                                 |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      regionProperties;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

regions
(
    solid ( v_CPU v_fins  )
    fluid ( domain0  )
);

// ************************************************************************* //
---blockMeshDict---
/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v2512                                 |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |
```

### tool: bash

`grep -rl "cellZone" /usr/lib/openfoam/openfoam2512/tutorials --include="*.dict...` exit 0

**input**

```
{
  "cmd": "grep -rl \"cellZone\" /usr/lib/openfoam/openfoam2512/tutorials --include=\"*.dict\" 2>/dev/null; grep -rln \"cellZone\" /usr/lib/openfoam/openfoam2512/tutorials -R 2>/dev/null | xargs grep -l \"hex\" 2>/dev/null | grep blockMeshDict | head"
}
```

**output**

```
exit_code: 0
```

### tool: bash

`find /usr/lib/openfoam/openfoam2512/src/mesh/blockMesh -iname "*.C" -o -iname ...` exit 0

**input**

```
{
  "cmd": "find /usr/lib/openfoam/openfoam2512/src/mesh/blockMesh -iname \"*.C\" -o -iname \"*.H\" | xargs grep -l \"zoneName\" 2>/dev/null | head; echo ---; grep -rn \"cellZone\\|zoneName\" /usr/lib/openfoam/openfoam2512/src/mesh/blockMesh/blockMesh/blockMeshCheck.C /usr/lib/openfoam/openfoam2512/src/mesh/blockMesh/block/block.C 2>/dev/null | head -20"
}
```

**output**

```
exit_code: 0

/usr/lib/openfoam/openfoam2512/src/mesh/blockMesh/PDRblockMesh/PDRblockBlockMesh.C
/usr/lib/openfoam/openfoam2512/src/mesh/blockMesh/blockDescriptor/blockDescriptor.C
/usr/lib/openfoam/openfoam2512/src/mesh/blockMesh/blockDescriptor/blockDescriptor.H
/usr/lib/openfoam/openfoam2512/src/mesh/blockMesh/blockDescriptor/blockDescriptorI.H
/usr/lib/openfoam/openfoam2512/src/mesh/blockMesh/blockMesh/blockMesh.C
/usr/lib/openfoam/openfoam2512/src/mesh/blockMesh/blockMesh/blockMeshCreate.C
/usr/lib/openfoam/openfoam2512/src/mesh/blockMesh/blocks/block/block.C
/usr/lib/openfoam/openfoam2512/src/mesh/blockMesh/blocks/block/block.H
/usr/lib/openfoam/openfoam2512/src/mesh/blockMesh/lnInclude/PDRblockBlockMesh.C
/usr/lib/openfoam/openfoam2512/src/mesh/blockMesh/lnInclude/block.C
---
```

### agent

Good, it's supported. Let me check the exact parsing syntax expected.

### tool: bash

`sed -n '1,80p' /usr/lib/openfoam/openfoam2512/src/mesh/blockMesh/blockDescript...` exit 1

**input**

```
{
  "cmd": "sed -n '1,80p' /usr/lib/openfoam/openfoam2512/src/mesh/blockMesh/blockDescriptor/blockDescriptor.C | grep -n \"zoneName\\|read\\|Istream\" "
}
```

**output**

```
exit_code: 1
```

### tool: bash

`grep -n "zoneName" /usr/lib/openfoam/openfoam2512/src/mesh/blockMesh/blockDesc...` exit 0

**input**

```
{
  "cmd": "grep -n \"zoneName\" /usr/lib/openfoam/openfoam2512/src/mesh/blockMesh/blockDescriptor/blockDescriptor.C"
}
```

**output**

```
exit_code: 0

204:    const word& zoneName
214:    zoneName_(zoneName),
246:    zoneName_(),
268:        zoneName_ = t.wordToken();
439:    if (bd.zoneName().size())
441:        os  << ' ' << bd.zoneName();
```

### tool: bash

`sed -n '240,290p' /usr/lib/openfoam/openfoam2512/src/mesh/blockMesh/blockDescr...` exit 0

**input**

```
{
  "cmd": "sed -n '240,290p' /usr/lib/openfoam/openfoam2512/src/mesh/blockMesh/blockDescriptor/blockDescriptor.C"
}
```

**output**

```
exit_code: 0

    vertices_(vertices),
    blockEdges_(edges),
    blockFaces_(faces),
    blockShape_(),
    expand_(),
    index_(blockIndex),
    zoneName_(),
    curvedFaces_(-1),
    nCurvedFaces_(0)
{
    // Read cell model and list of vertices (potentially with variables)
    word model(is);
    blockShape_ = cellShape
    (
        model,
        blockMeshTools::read<label>
        (
            is,
            dict.subOrEmptyDict("namedVertices")
        )
    );

    // Examine next token
    token t(is);

    // Optional zone name
    if (t.isWord())
    {
        zoneName_ = t.wordToken();

        // Examine next token
        is >> t;
    }
    is.putBack(t);

    if (t.isPunctuation())
    {
        // New-style: read a list of 3 values
        if (t.pToken() == token::BEGIN_LIST)
        {
            is >> ijkMesh::sizes();
        }
        else
        {
            FatalIOErrorInFunction(is)
                << "Incorrect token while reading n, expected '(', found "
                << t.info()
                << exit(FatalIOError);
        }
    }
    else
```

### tool: bash

`cd /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleF...` exit 0

**input**

```
{
  "cmd": "cd /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/heatExchanger; find . -maxdepth 3 -type f | sort"
}
```

**output**

```
exit_code: 0

./0.orig/air/T
./0.orig/air/U
./0.orig/air/alphat
./0.orig/air/epsilon
./0.orig/air/k
./0.orig/air/nut
./0.orig/air/p
./0.orig/air/p_rgh
./0.orig/porous/AoV
./0.orig/porous/T
./0.orig/porous/U
./0.orig/porous/htcConst
./0.orig/porous/p
./0.orig/porous/p_rgh
./Allclean
./Allrun
./Allrun-parallel
./Allrun.pre
./constant/air/MRFProperties
./constant/air/fvOptions
./constant/air/radiationProperties
./constant/air/thermophysicalProperties
./constant/air/turbulenceProperties
./constant/g
./constant/porous/fvOptions
./constant/porous/thermophysicalProperties
./constant/porous/turbulenceProperties
./constant/regionProperties
./system/air/blockMeshDict
./system/air/createBafflesDict
./system/air/decomposeParDict
./system/air/fvSchemes
./system/air/fvSolution
./system/air/topoSetDict.1
./system/air/topoSetDict.2
./system/controlDict
./system/decomposeParDict
./system/fvSchemes
./system/fvSolution
./system/porous/blockMeshDict
./system/porous/decomposeParDict
./system/porous/fvSchemes
./system/porous/fvSolution
```

### tool: bash

`find /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpl...` exit 0

**input**

```
{
  "cmd": "find /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/multiRegionHeaterRadiation -maxdepth 1; echo ---; find /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/multiRegionHeater -maxdepth 3 -type f | sort"
}
```

**output**

```
exit_code: 0

/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/multiRegionHeaterRadiation
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/multiRegionHeaterRadiation/0.orig
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/multiRegionHeaterRadiation/Allclean
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/multiRegionHeaterRadiation/Allrun
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/multiRegionHeaterRadiation/Allrun-parallel
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/multiRegionHeaterRadiation/Allrun.pre
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/multiRegionHeaterRadiation/constant
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/multiRegionHeaterRadiation/system
---
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/multiRegionHeater/0.orig/T
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/multiRegionHeater/0.orig/U
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/multiRegionHeater/0.orig/epsilon
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/multiRegionHeater/0.orig/k
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMulti
```

### agent

This is exactly the topoSet+splitMeshRegions pattern I need. Let me look at the key files: topoSetDict, 0.orig/T, Allrun.pre, and the single global fvSchemes/fvSolution/controlDict.

### tool: bash

`cd /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/mu...` exit 0

**input**

```
{
  "cmd": "cd /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/multiRegionHeater\necho ===topoSetDict===; cat system/topoSetDict\necho ===Allrun.pre===; cat Allrun.pre\necho ===Allrun===; cat Allrun\necho ===T.orig===; cat 0.orig/T\necho ===regionProperties===; cat constant/regionProperties"
}
```

**output**

```
exit_code: 0

===topoSetDict===
/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v2512                                 |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      topoSetDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

actions
(
    // Heater
    {
        name    heaterCellSet;
        type    cellSet;
        action  new;
        source  boxToCell;
        box     (-0.01001 0 -100) (0.01001 0.00999 100);
    }
    {
        name    heaterCellSet;
        type    cellSet;
        action  add;
        source  boxToCell;
        box     (-0.01001 -100 -0.01001) (0.01001 0.00999 0.01001);
    }
    {
        name    heater;
        type    cellZoneSet;
        action  new;
        source  setToCellZone;
        set     heaterCellSet;
    }

    // leftSolid
    {
        name    leftSolidCellSet;
        type    cellSet;
```

### tool: bash

`cd /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/mu...` exit 2

**input**

```
{
  "cmd": "cd /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/multiRegionHeater\nfor f in 0.orig/U 0.orig/p 0.orig/p_rgh 0.orig/k 0.orig/epsilon; do echo ===$f===; cat $f; done\necho ===heater/changeDictionaryDict===; cat system/heater/changeDictionaryDict\necho ===topAir/changeDictionaryDict===; cat system/topAir/changeDictionaryDict\necho ===heater thermophysicalProperties===; cat constant/heater/thermophysicalProperties\necho ===topAir thermophysicalProperties===; cat constant/topAir/thermophysicalProperties\necho ===turbulenceProperties(topAir)===; cat constant/topAir/turbulenceProperties 2>/dev/null\necho ===controlDict===; cat system/controlDict\necho ===fvSchemes global===; cat system/fvSchemes\necho ===fvSolution global===; cat system/fvSolution\necho ===heater fvSchemes===; cat system/heater/fvSchemes\necho ===heater fvSolution===; cat system/heater/fvS...
```

**output**

```
exit_code: 2
```

### tool: bash

`cd /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/mu...` exit 0

**input**

```
{
  "cmd": "cd /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/multiRegionHeater\nfor f in 0.orig/U 0.orig/p 0.orig/p_rgh 0.orig/k 0.orig/epsilon; do echo ===$f===; cat \"$f\"; done"
}
```

**output**

```
exit_code: 0

===0.orig/U===
/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v2512                                 |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volVectorField;
    object      U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 1 -1 0 0 0 0];

internalField   uniform (0.01 0 0);

boundaryField
{
    ".*"
    {
        type            calculated;
        value           $internalField;
    }
}

// ************************************************************************* //
===0.orig/p===
/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v2512                                 |
|   \\  /    A nd
```

### tool: bash

`cd /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/mu...` exit 0

**input**

```
{
  "cmd": "cd /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/multiRegionHeater\necho ===heater cDD===; cat system/heater/changeDictionaryDict\necho ===topAir cDD===; cat system/topAir/changeDictionaryDict\necho ===bottomWater cDD===; cat system/bottomWater/changeDictionaryDict"
}
```

**output**

```
exit_code: 0

===heater cDD===
/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v2512                                 |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      changeDictionaryDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

boundary
{
    minY
    {
        type            patch;
        inGroups        (coupleGroup);
    }
    minZ
    {
        type            patch;
    }
    maxZ
    {
        type            patch;
    }
}

T
{
    internalField   uniform 300;

    boundaryField
    {
        ".*"
        {
            type            zeroGradient;
            value           uniform 300;
        }
        "heater_to_.*"
        {
            type            compressible::turbulentTemperatureRadCoupledMixed;
            Tnbr            T;
            kappaMethod     solidThermo;
            value           unifor
```

### tool: bash

`cd /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/mu...` exit 0

**input**

```
{
  "cmd": "cd /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/multiRegionHeater\necho ===heater thermophysicalProperties===; cat constant/heater/thermophysicalProperties\necho ===topAir thermophysicalProperties===; cat constant/topAir/thermophysicalProperties\necho ===heater radiationProperties===; cat constant/heater/radiationProperties\necho ===bottomWater thermophysicalProperties===; cat constant/bottomWater/thermophysicalProperties\necho ===controlDict===; cat system/controlDict\necho ===global fvSchemes===; cat system/fvSchemes\necho ===global fvSolution===; cat system/fvSolution\necho ===heater fvSchemes===; cat system/heater/fvSchemes\necho ===heater fvSolution===; cat system/heater/fvSolution\necho ===decomposeParDict===; cat system/decomposeParDict"
}
```

**output**

```
exit_code: 0

===heater thermophysicalProperties===
/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v2512                                 |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      thermophysicalProperties;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

thermoType
{
    type            heSolidThermo;
    mixture         pureMixture;
    transport       constIso;
    thermo          hConst;
    equationOfState rhoConst;
    specie          specie;
    energy          sensibleEnthalpy;
}

mixture
{
    specie
    {
        molWeight   50;
    }
    transport
    {
        kappa   80;
    }
    thermodynamics
    {
        Hf      0;
        Cp      450;
    }
    equationOfState
    {
        rho     8000;
    }
}

// ************************************************************************* //
===topAir thermophysicalProper
```

### tool: bash

`cd /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleF...` exit 0

**input**

```
{
  "cmd": "cd /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/multiRegionHeaterRadiation\necho ===controlDict===; cat system/controlDict\necho ===global fvSolution===; cat system/fvSolution\necho ===heater fvSolution===; cat system/heater/fvSolution\necho ===topAir fvSolution===; cat system/topAir/fvSolution\necho ===topAir fvSchemes===; cat system/topAir/fvSchemes\necho ===heater fvSchemes===; cat system/heater/fvSchemes\necho ===cellZone approach — topoSetDict===; ls system; cat system/topoSetDict 2>/dev/null | head -50"
}
```

**output**

```
exit_code: 0

===controlDict===
/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v2512                                 |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      controlDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

application     chtMultiRegionSimpleFoam;

startFrom       startTime;

startTime       0;

stopAt          endTime;

endTime         2000;

deltaT          1;

writeControl    timeStep;

writeInterval   300;

purgeWrite      10;

writeFormat     ascii;

writePrecision  7;

writeCompression off;

timeFormat      general;

timePrecision   6;

runTimeModifiable true;

functions
{
    multiRegion
    {
        type    multiRegion;
        libs    (utilityFunctionObjects);

        // regions ( ".*Air" );

        function
        {
            // Actual object specification
            type    fieldMinMax;
```

### tool: bash

`cat /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimple...` exit 0

**input**

```
{
  "cmd": "cat /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/multiRegionHeaterRadiation/constant/g\necho ===turb topAir===; cat /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/multiRegionHeaterRadiation/constant/topAir/turbulenceProperties 2>/dev/null\nfind /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/multiRegionHeaterRadiation/constant -maxdepth 2\necho ===fvOptions===; cat /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/multiRegionHeaterRadiation/constant/topAir/fvOptions 2>/dev/null\ngrep -rl \"laminar;\" /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam 2>/dev/null"
}
```

**output**

```
exit_code: 0

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v2512                                 |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       uniformDimensionedVectorField;
    object      g;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 1 -2 0 0 0 0];
value           (0 -9.81 0);

// ************************************************************************* //
===turb topAir===
/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v2512                                 |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |
```

### tool: bash

`cd /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleF...` exit 0

**input**

```
{
  "cmd": "cd /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/multiRegionHeaterRadiation\ncat system/bottomAir/changeDictionaryDict\necho ===0.orig===; ls 0.orig\necho ===Allrun.pre===; cat Allrun.pre 2>/dev/null; cat Allrun"
}
```

**output**

```
exit_code: 0

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v2512                                 |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      changeDictionaryDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

boundary
{
    minX
    {
        type            wall;
        inGroups        2(wall viewFactorWall);
    }
    maxX
    {
        type            wall;
        inGroups        2(wall viewFactorWall);
    }
    ".*"
    {
        inGroups        2(wall viewFactorWall);
    }
}

U
{
    internalField   uniform (0.01 0 0);
    boundaryField
    {
        ".*"
        {
            type            fixedValue;
            value           uniform (0 0 0);
        }
    }
}

T
{
    internalField   uniform 300;
    boundaryField
    {
        ".*"
        {
            type            zeroGradient;
        }

        "
```

### tool: bash

`cd /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleF...` exit 0

**input**

```
{
  "cmd": "cd /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/externalCoupledHeater\nls 0.orig; echo ---; ls 0.orig/bottomWater 2>/dev/null; echo ---turbProps---; cat constant/bottomWater/turbulenceProperties\necho ---changeDict---; cat system/bottomWater/changeDictionaryDict 2>/dev/null | head -80"
}
```

**output**

```
exit_code: 0

T
U
epsilon
k
p
p_rgh
---
---turbProps---
/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v2512                                 |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      turbulenceProperties;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

simulationType  laminar;

// ************************************************************************* //
---changeDict---
/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v2512                                 |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |
```

### tool: bash

`grep -rl "externalWallHeatFluxTemperature" /usr/lib/openfoam/openfoam2512/tuto...` exit 0

**input**

```
{
  "cmd": "grep -rl \"externalWallHeatFluxTemperature\" /usr/lib/openfoam/openfoam2512/tutorials 2>/dev/null | head -5"
}
```

**output**

```
exit_code: 0

/usr/lib/openfoam/openfoam2512/tutorials/combustion/fireFoam/LES/compartmentFire/0.orig/panelRegion/T
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/externalSolarLoad/0.orig/floor/T
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/externalSolarLoad/system/floor/changeDictionaryDict
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/reverseBurner/0.orig/solid/T
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/solarBeamWithTrees/0.orig/floor/T
```

### tool: bash

`grep -B2 -A20 "externalWallHeatFluxTemperature" /usr/lib/openfoam/openfoam2512...` exit 0

**input**

```
{
  "cmd": "grep -B2 -A20 \"externalWallHeatFluxTemperature\" /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/reverseBurner/0.orig/solid/T"
}
```

**output**

```
exit_code: 0

    external
    {
        type            externalWallHeatFluxTemperature;
        kappaMethod     solidThermo;
        mode            coefficient;
        h               uniform 1e3;
        Ta              $internalField;
        value           $internalField;
    }

    solid_to_gas
    {
        type            compressible::turbulentTemperatureRadCoupledMixed;
        value           $internalField;
        Tnbr            T;
        kappaMethod     solidThermo;
    }
}

// ************************************************************************* //
```

### tool: bash

`find / -iname "externalWallHeatFluxTemperatureFvPatchScalarField.C" 2>/dev/nul...` exit 0

**input**

```
{
  "cmd": "find / -iname \"externalWallHeatFluxTemperatureFvPatchScalarField.C\" 2>/dev/null | head -1 | xargs -I{} sed -n '1,120p' {} | grep -n \"mode\\|power\\|flux\\|coefficient\" | head -40"
}
```

**output**

```
exit_code: 0

45:    { operationMode::fixedPower, "power" },
46:    { operationMode::fixedHeatFlux, "flux" },
47:    { operationMode::fixedHeatTransferCoeff, "coefficient" },
62:    mode_(fixedHeatFlux),
90:    mode_(operationModeNames.get("mode", dict)),
102:    switch (mode_)
```

### tool: bash

`f=$(find / -iname "externalWallHeatFluxTemperatureFvPatchScalarField.C" 2>/dev...` exit 0

**input**

```
{
  "cmd": "f=$(find / -iname \"externalWallHeatFluxTemperatureFvPatchScalarField.C\" 2>/dev/null | head -1); sed -n '95,180p' \"$f\""
}
```

**output**

```
exit_code: 0

    relaxation_(dict.getOrDefault<scalar>("relaxation", 1)),
    emissivity_(dict.getOrDefault<scalar>("emissivity", 0)),
    qrRelaxation_(dict.getOrDefault<scalar>("qrRelaxation", 1)),
    qrName_(dict.getOrDefault<word>("qr", "none")),
    thicknessLayers_(),
    kappaLayers_()
{
    switch (mode_)
    {
        case fixedPower:
        {
            Q_ = Function1<scalar>::New("Q", dict, &db());
            break;
        }
        case fixedHeatFlux:
        {
            q_ = PatchFunction1<scalar>::New(patch().patch(), "q", dict);
            break;
        }
        case fixedHeatTransferCoeff:
        {
            h_ = PatchFunction1<scalar>::New(patch().patch(), "h", dict);
            Ta_ = Function1<scalar>::New("Ta", dict, &db());

            if (dict.readIfPresent("thicknessLayers", thicknessLayers_))
            {
                dict.readEntry("kappaLayers", kappaLayers_);

                if (thicknessLayers_.size() != kappaLayers_.size())
                {
                    FatalIOErrorInFunction(dict)
                        << "\n number of layers for thicknessLayers and "
                        << "kappaLayers must be the same"
                        << "\n for patch " << p.name()
                        << " of field " << internalField().name()
                        << " in file " << internalField().objectPath()
```

### tool: bash

`f=$(find / -iname "externalWallHeatFluxTemperatureFvPatchScalarField.C" 2>/dev...` exit 0

**input**

```
{
  "cmd": "f=$(find / -iname \"externalWallHeatFluxTemperatureFvPatchScalarField.C\" 2>/dev/null | head -1); grep -n \"fixedPower\" -A15 \"$f\" | head -40"
}
```

**output**

```
exit_code: 0

45:    { operationMode::fixedPower, "power" },
46-    { operationMode::fixedHeatFlux, "flux" },
47-    { operationMode::fixedHeatTransferCoeff, "coefficient" },
48-});
49-
50-
51-// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
52-
53-Foam::externalWallHeatFluxTemperatureFvPatchScalarField::
54-externalWallHeatFluxTemperatureFvPatchScalarField
55-(
56-    const fvPatch& p,
57-    const DimensionedField<scalar, volMesh>& iF
58-)
59-:
60-    mixedFvPatchScalarField(p, iF),
--
104:        case fixedPower:
105-        {
106-            Q_ = Function1<scalar>::New("Q", dict, &db());
107-            break;
108-        }
109-        case fixedHeatFlux:
110-        {
111-            q_ = PatchFunction1<scalar>::New(patch().patch(), "q", dict);
112-            break;
113-        }
114-        case fixedHeatTransferCoeff:
115-        {
116-            h_ = PatchFunction1<scalar>::New(patch().patch(), "h", dict);
117-            Ta_ = Function1<scalar>::New("Ta", dict, &db());
118-
119-            if (dict.readIfPresent("thicknessLayers", thicknessLayers_))
--
328:        case fixedPower:
329-        {
330-            const scalar heatPower =
331-                Q_->value(this->db().time().timeOutputValue());
332-
333-            refGrad() = (heatPower/gSum(patch().magSf()) + qr)/kappa(Tp);
```

### agent

Good — I found the right tutorial pattern (chtMultiRegionSimpleFoam + topoSet/splitMeshRegions from `multiRegionHeater`). Now I'll build a purpose-made case: a symmetric unit-cell CHT model of one fin channel of the heat sink (base + fin in aluminum, air channel, laminar forced convection), which is a legitimate coarse "quick look" for this geometry. Let me write the case files.

### tool: bash

`mkdir -p /work/20260507-080356-73d0/case/{system/fluid,system/solid,constant/f...` exit 0

**input**

```
{
  "cmd": "mkdir -p /work/20260507-080356-73d0/case/{system/fluid,system/solid,constant/fluid,constant/solid,0.orig}\necho ok"
}
```

**output**

```
exit_code: 0

ok
```

### tool: write_file

`/work/20260507-080356-73d0/notes.md`

**input**

```
{
  "path": "/work/20260507-080356-73d0/notes.md",
  "content": "# Heat sink CHT quick look\n\n## Question\n15 W CPU, finned aluminium heat sink, 2 m/s crossflow. Base temperature and\noverall thermal resistance (K/W).\n\n## Modelling choice (read this before trusting the numbers)\nA full 3D heat sink (base + N fin array) in a duct is expensive to mesh well\n(snappyHexMesh, thin fin boundary layers, tens of thousands of cells minimum).\nFor a *quick look* I instead modelled a symmetric unit cell: one fin plus the\nhalf-channel of air on each side of it, using symmetry planes at the mid-channel\npositions on both sides. This is the standard reduced model for a plate-fin\narray with many identical, evenly-spaced fins -- it captures the real\nconjugate heat transfer (aluminium conduction + convecting air) at a fraction\nof the cost, but it assumes:\n\n  - all fin channels carry identical, u...
```

**output**

```
wrote 2775 bytes to /work/20260507-080356-73d0/notes.md
```

### tool: write_file

`/work/20260507-080356-73d0/case/system/blockMeshDict`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/system/blockMeshDict",
  "content": "/*--------------------------------*- C++ -*----------------------------------*\\\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      blockMeshDict;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\n// Unit-cell heat sink model: one fin + half-channel on each side.\n// x: streamwise (fin/base length), y: pitch (fin thickness + channels),\n// z: base thickness + fin height.\n\nscale 1;\n\n// x\n#define X0 0.0\n#define X1 0.04\n\n// y\n#define Y0 0.0\n#define Y1 0.005\n\n// z\n#define Z0 0.0\n#define Z1 0.003\n#define Z2 0.023\n\nvertices\n(\n    ( $X0 $Y0 $Z0 )   // 0\n    ( $X1 $Y0 $Z0 )   // 1\n    ( $X1 $Y1 $Z0 )   // 2\n    ( $X0 $Y1 $Z0 )   // 3\n    ( $X0 $Y0 $Z1 )   // 4\n    ( $X1 $Y0 $Z1 )   // 5\n    ( $X1 $Y1...
```

**output**

```
wrote 1933 bytes to /work/20260507-080356-73d0/case/system/blockMeshDict
```

### tool: write_file

`/work/20260507-080356-73d0/case/system/topoSetDict`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/system/topoSetDict",
  "content": "/*--------------------------------*- C++ -*----------------------------------*\\\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      topoSetDict;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\nactions\n(\n    // Base slab (all of the lower block) -> solid\n    {\n        name    solidCellSet;\n        type    cellSet;\n        action  new;\n        source  boxToCell;\n        box     (-1 -1 -1) (1 1 0.0031);\n    }\n\n    // Fin (within the upper block, y between the two channels) -> solid\n    {\n        name    solidCellSet;\n        type    cellSet;\n        action  add;\n        source  boxToCell;\n        box     (-1 0.00174 0.0029) (1 0.00326 1);\n    }\n\n    {\n        name    solid;\n        type    cellZoneS...
```

**output**

```
wrote 1394 bytes to /work/20260507-080356-73d0/case/system/topoSetDict
```

### agent

Now the region properties, global controlDict/fvSchemes/fvSolution, and 0.orig fields.

### tool: write_file

`/work/20260507-080356-73d0/case/constant/regionProperties`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/constant/regionProperties",
  "content": "/*--------------------------------*- C++ -*----------------------------------*\\\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      regionProperties;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\nregions\n(\n    fluid ( fluid )\n    solid ( solid )\n);\n\n// ************************************************************************* //\n"
}
```

**output**

```
wrote 414 bytes to /work/20260507-080356-73d0/case/constant/regionProperties
```

### tool: write_file

`/work/20260507-080356-73d0/case/constant/g`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/constant/g",
  "content": "/*--------------------------------*- C++ -*----------------------------------*\\\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       uniformDimensionedVectorField;\n    object      g;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\ndimensions      [0 1 -2 0 0 0 0];\nvalue           (0 0 -9.81);\n\n// ************************************************************************* //\n"
}
```

**output**

```
wrote 428 bytes to /work/20260507-080356-73d0/case/constant/g
```

### tool: write_file

`/work/20260507-080356-73d0/case/constant/fluid/thermophysicalProperties`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/constant/fluid/thermophysicalProperties",
  "content": "/*--------------------------------*- C++ -*----------------------------------*\\\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      thermophysicalProperties;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\nthermoType\n{\n    type            heRhoThermo;\n    mixture         pureMixture;\n    transport       const;\n    thermo          hConst;\n    equationOfState rhoConst;\n    specie          specie;\n    energy          sensibleEnthalpy;\n}\n\nmixture\n{\n    specie\n    {\n        molWeight       28.9;\n    }\n    equationOfState\n    {\n        rho             1.2;\n    }\n    thermodynamics\n    {\n        Cp              1005;\n        Hf              0;\n    }\n    transport\n    {\n...
```

**output**

```
wrote 906 bytes to /work/20260507-080356-73d0/case/constant/fluid/thermophysicalProperties
```

### tool: write_file

`/work/20260507-080356-73d0/case/constant/fluid/turbulenceProperties`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/constant/fluid/turbulenceProperties",
  "content": "/*--------------------------------*- C++ -*----------------------------------*\\\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      turbulenceProperties;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\nsimulationType  laminar;\n\n// ************************************************************************* //\n"
}
```

**output**

```
wrote 390 bytes to /work/20260507-080356-73d0/case/constant/fluid/turbulenceProperties
```

### tool: write_file

`/work/20260507-080356-73d0/case/constant/solid/thermophysicalProperties`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/constant/solid/thermophysicalProperties",
  "content": "/*--------------------------------*- C++ -*----------------------------------*\\\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      thermophysicalProperties;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\nthermoType\n{\n    type            heSolidThermo;\n    mixture         pureMixture;\n    transport       constIso;\n    thermo          hConst;\n    equationOfState rhoConst;\n    specie          specie;\n    energy          sensibleEnthalpy;\n}\n\nmixture\n{\n    specie\n    {\n        molWeight   26.98;\n    }\n    transport\n    {\n        kappa   205;\n    }\n    thermodynamics\n    {\n        Hf      0;\n        Cp      900;\n    }\n    equationOfState\n    {\n        rho     2700;\n    }\n...
```

**output**

```
wrote 841 bytes to /work/20260507-080356-73d0/case/constant/solid/thermophysicalProperties
```

### agent

Now the radiationProperties (off) for both regions, global controlDict, and empty top-level fvSchemes/fvSolution:

### tool: write_file

`/work/20260507-080356-73d0/case/constant/fluid/radiationProperties`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/constant/fluid/radiationProperties",
  "content": "/*--------------------------------*- C++ -*----------------------------------*\\\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      radiationProperties;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\nradiation off;\nradiationModel none;\n\n// ************************************************************************* //\n"
}
```

**output**

```
wrote 400 bytes to /work/20260507-080356-73d0/case/constant/fluid/radiationProperties
```

### tool: bash

`cp /work/20260507-080356-73d0/case/constant/fluid/radiationProperties /work/20...` exit 0

**input**

```
{
  "cmd": "cp /work/20260507-080356-73d0/case/constant/fluid/radiationProperties /work/20260507-080356-73d0/case/constant/solid/radiationProperties"
}
```

**output**

```
exit_code: 0
```

### tool: write_file

`/work/20260507-080356-73d0/case/system/controlDict`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/system/controlDict",
  "content": "/*--------------------------------*- C++ -*----------------------------------*\\\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      controlDict;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\napplication     chtMultiRegionSimpleFoam;\n\nstartFrom       startTime;\n\nstartTime       0;\n\nstopAt          endTime;\n\nendTime         1500;\n\ndeltaT          1;\n\nwriteControl    timeStep;\n\nwriteInterval   100;\n\npurgeWrite      2;\n\nwriteFormat     ascii;\n\nwritePrecision  7;\n\nwriteCompression off;\n\ntimeFormat      general;\n\ntimePrecision   6;\n\nrunTimeModifiable true;\n\nfunctions\n{\n    fluidMinMaxT\n    {\n        type        fieldMinMax;\n        libs        (fieldFunctionObjects);\n        region...
```

**output**

```
wrote 1540 bytes to /work/20260507-080356-73d0/case/system/controlDict
```

### tool: bash

`cat > /work/20260507-080356-73d0/case/system/fvSchemes << 'EOF'` exit 0

**input**

```
{
  "cmd": "cat > /work/20260507-080356-73d0/case/system/fvSchemes << 'EOF'\n/*--------------------------------*- C++ -*----------------------------------*\\\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      fvSchemes;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\nddtSchemes {}\ngradSchemes {}\ndivSchemes {}\nlaplacianSchemes {}\ninterpolationSchemes {}\nsnGradSchemes {}\n\n// ************************************************************************* //\nEOF\ncat > /work/20260507-080356-73d0/case/system/fvSolution << 'EOF'\n/*--------------------------------*- C++ -*----------------------------------*\\\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      fvSolution;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *...
```

**output**

```
exit_code: 0

ok
```

### agent

Now the per-region fvSchemes/fvSolution:

### tool: write_file

`/work/20260507-080356-73d0/case/system/fluid/fvSchemes`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/system/fluid/fvSchemes",
  "content": "/*--------------------------------*- C++ -*----------------------------------*\\\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      fvSchemes;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\nddtSchemes\n{\n    default         steadyState;\n}\n\ngradSchemes\n{\n    default         Gauss linear;\n}\n\ndivSchemes\n{\n    default         none;\n    div(phi,U)      bounded Gauss upwind;\n    energy          bounded Gauss upwind;\n    div(phi,K)      $energy;\n    div(phi,h)      $energy;\n    div(((rho*nuEff)*dev2(T(grad(U))))) Gauss linear;\n}\n\nlaplacianSchemes\n{\n    default         Gauss linear uncorrected;\n}\n\ninterpolationSchemes\n{\n    default         linear;\n}\n\nsnGradSchemes\n{\n    default         unco...
```

**output**

```
wrote 865 bytes to /work/20260507-080356-73d0/case/system/fluid/fvSchemes
```

### tool: write_file

`/work/20260507-080356-73d0/case/system/fluid/fvSolution`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/system/fluid/fvSolution",
  "content": "/*--------------------------------*- C++ -*----------------------------------*\\\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      fvSolution;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\nsolvers\n{\n    rho\n    {\n        solver          PCG;\n        preconditioner  DIC;\n        tolerance       1e-7;\n        relTol          0;\n    }\n\n    p_rgh\n    {\n        solver           GAMG;\n        tolerance        1e-8;\n        relTol           0.01;\n        smoother         GaussSeidel;\n    }\n\n    \"(U|h)\"\n    {\n        solver           PBiCGStab;\n        preconditioner   DILU;\n        tolerance        1e-8;\n        relTol           0.1;\n    }\n}\n\nSIMPLE\n{\n    momentumPredictor yes;\n    nNo...
```

**output**

```
wrote 1290 bytes to /work/20260507-080356-73d0/case/system/fluid/fvSolution
```

### tool: write_file

`/work/20260507-080356-73d0/case/system/solid/fvSchemes`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/system/solid/fvSchemes",
  "content": "/*--------------------------------*- C++ -*----------------------------------*\\\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      fvSchemes;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\nddtSchemes\n{\n    default         steadyState;\n}\n\ngradSchemes\n{\n    default         Gauss linear;\n}\n\ndivSchemes\n{\n    default         none;\n}\n\nlaplacianSchemes\n{\n    default             none;\n    laplacian(alpha,h)  Gauss linear uncorrected;\n}\n\ninterpolationSchemes\n{\n    default         linear;\n}\n\nsnGradSchemes\n{\n    default         uncorrected;\n}\n\n// ************************************************************************* //\n"
}
```

**output**

```
wrote 703 bytes to /work/20260507-080356-73d0/case/system/solid/fvSchemes
```

### tool: write_file

`/work/20260507-080356-73d0/case/system/solid/fvSolution`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/system/solid/fvSolution",
  "content": "/*--------------------------------*- C++ -*----------------------------------*\\\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      fvSolution;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\nsolvers\n{\n    h\n    {\n        solver           PCG;\n        preconditioner   DIC;\n        tolerance        1e-8;\n        relTol           0.01;\n    }\n}\n\nSIMPLE\n{\n    nNonOrthogonalCorrectors 0;\n\n    residualControl\n    {\n        h               1e-7;\n    }\n}\n\nrelaxationFactors\n{\n    equations\n    {\n        h               0.7;\n    }\n}\n\n// ************************************************************************* //\n"
}
```

**output**

```
wrote 692 bytes to /work/20260507-080356-73d0/case/system/solid/fvSolution
```

### agent

Now the 0.orig fields (single-mesh placeholders before split) and the changeDictionaryDict for each region.

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\nfor f in T U p p_rgh k epsilon; do\ncase $f in\n  U) dims=\"[0 1 -1 0 0 0 0]\"; ival=\"uniform (2 0 0)\";;\n  p|p_rgh) dims=\"[1 -1 -2 0 0 0 0]\"; ival=\"uniform 1e5\";;\n  T) dims=\"[0 0 0 1 0 0 0]\"; ival=\"uniform 298.15\";;\n  k) dims=\"[0 2 -2 0 0 0 0]\"; ival=\"uniform 0.001\";;\n  epsilon) dims=\"[0 2 -3 0 0 0 0]\"; ival=\"uniform 0.0001\";;\nesac\nclass=\"volScalarField\"\nif [ \"$f\" = \"U\" ]; then class=\"volVectorField\"; fi\ncat > 0.orig/$f << EOF\n/*--------------------------------*- C++ -*----------------------------------*\\\\\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       $class;\n    object      $f;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\ndimensions      $dims;\n\ninternalField   $ival;\n\nboundaryField\n{\n    \".*\"\n    {\n        type...
```

**output**

```
exit_code: 0

T
U
epsilon
k
p
p_rgh
```

### agent

Now the changeDictionaryDicts for fluid and solid regions.

### tool: write_file

`/work/20260507-080356-73d0/case/system/fluid/changeDictionaryDict`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/system/fluid/changeDictionaryDict",
  "content": "/*--------------------------------*- C++ -*----------------------------------*\\\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      changeDictionaryDict;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\nboundary\n{\n    sideMinY\n    {\n        type            symmetryPlane;\n    }\n    sideMaxY\n    {\n        type            symmetryPlane;\n    }\n}\n\nU\n{\n    internalField   uniform (2 0 0);\n\n    boundaryField\n    {\n        inlet\n        {\n            type            fixedValue;\n            value           uniform (2 0 0);\n        }\n        outlet\n        {\n            type            inletOutlet;\n            inletValue      uniform (0 0 0);\n            value           uniform (2 0 0);\...
```

**output**

```
wrote 3502 bytes to /work/20260507-080356-73d0/case/system/fluid/changeDictionaryDict
```

### tool: write_file

`/work/20260507-080356-73d0/case/system/solid/changeDictionaryDict`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/system/solid/changeDictionaryDict",
  "content": "/*--------------------------------*- C++ -*----------------------------------*\\\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      changeDictionaryDict;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\nboundary\n{\n    sideMinY\n    {\n        type            symmetryPlane;\n    }\n    sideMaxY\n    {\n        type            symmetryPlane;\n    }\n}\n\nT\n{\n    internalField   uniform 310;\n\n    boundaryField\n    {\n        sideMinY\n        {\n            type            symmetryPlane;\n        }\n        sideMaxY\n        {\n            type            symmetryPlane;\n        }\n        baseBottom\n        {\n            type            externalWallHeatFluxTemperature;\n            mode...
```

**output**

```
wrote 1339 bytes to /work/20260507-080356-73d0/case/system/solid/changeDictionaryDict
```

### agent

Now the Allrun.pre script that builds the mesh, splits regions, and applies BCs, following the tutorial pattern:

### tool: write_file

`/work/20260507-080356-73d0/case/Allrun.pre`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/Allrun.pre",
  "content": "#!/bin/sh\ncd \"${0%/*}\" || exit\n. ${WM_PROJECT_DIR:?}/bin/tools/RunFunctions\n#------------------------------------------------------------------------------\n\nrunApplication blockMesh\nrunApplication topoSet\n\nrestore0Dir\n\nrunApplication splitMeshRegions -cellZones -overwrite\n\nfields=\"U p p_rgh k epsilon\"\nfor region in $(foamListRegions solid)\ndo\n    remove0DirFields -region \"$region\" -- $fields\ndone\n\nfor region in $(foamListRegions)\ndo\n    runApplication -s \"$region\" changeDictionary -region \"$region\"\ndone\n\necho \"Allrun.pre done\"\n#------------------------------------------------------------------------------\n"
}
```

**output**

```
wrote 613 bytes to /work/20260507-080356-73d0/case/Allrun.pre
```

### tool: bash

`chmod +x /work/20260507-080356-73d0/case/Allrun.pre` exit 0

**input**

```
{
  "cmd": "chmod +x /work/20260507-080356-73d0/case/Allrun.pre\ncd /work/20260507-080356-73d0/case\nblockMesh 2>&1 | tail -40"
}
```

**output**

```
exit_code: 0

Create time

--> FOAM Warning : 
    From bool Foam::IOobject::readHeader(Foam::dictionary&, Foam::Istream&)
    in file db/IOobject/IOobjectReadHeader.C at line 118
    Reading "system/controlDict" at line 77
    First token could not be read or is not 'FoamFile'

Check header is of the form:

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2512                                  |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    arch        "LSB;label=32;scalar=64";
    class       dictionary;
    location    "system";
    object      controlDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

--> FOAM FATAL IO ERROR: (openfoam-2512)
problem while reading header for object controlDict

file: system/controlDict at line 77.

    From virtual Foam::autoPtr<Foam::ISstream> Foam::fileOperations::uncollatedFileOperation::readStream(Foam::regIOobject&, const Fo
```

### tool: bash

`cat -A /work/20260507-080356-73d0/case/system/controlDict | sed -n '70,90p'` exit 0

**input**

```
{
  "cmd": "cat -A /work/20260507-080356-73d0/case/system/controlDict | sed -n '70,90p'"
}
```

**output**

```
exit_code: 0

        writeControl    timeStep;$
        writeInterval   20;$
        writeFields     no;$
    }$
}$
$
// ************************************************************************* //$
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\npython3 - << 'EOF'\nimport re\np=\"system/controlDict\"\ns=open(p).read()\ns2 = re.sub(r\"functions\\n\\{.*?\\n\\}\\n\", \"functions\\n{\\n}\\n\", s, flags=re.S)\nopen(p,\"w\").write(s2)\nEOF\ntail -20 system/controlDict\nblockMesh 2>&1 | tail -30"
}
```

**output**

```
exit_code: 0

purgeWrite      2;

writeFormat     ascii;

writePrecision  7;

writeCompression off;

timeFormat      general;

timePrecision   6;

runTimeModifiable true;

functions
{
}

// ************************************************************************* //
/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2512                                  |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    arch        "LSB;label=32;scalar=64";
    class       dictionary;
    location    "system";
    object      controlDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

--> FOAM FATAL IO ERROR: (openfoam-2512)
problem while reading header for object controlDict

file: system/controlDict at line 46.

    From virtual Foam::autoPtr<Foam::ISstream> Foam::fileOperations::uncollatedFileOperation::readStream(Foam::regIOobject&, const Foam::fileName&, const Foam::word&, bool) co
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\nblockMesh 2>&1 | head -60"
}
```

**output**

```
exit_code: 0

/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2512                                  |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : _87ed40d2-20251219 OPENFOAM=2512 version=2512
Arch   : "LSB;label=32;scalar=64"
Exec   : blockMesh
Date   : Aug 29 2026
Time   : 00:22:54
Host   : modal
PID    : 50359
I/O    : uncollated
Case   : /work/20260507-080356-73d0/case
nProcs : 1
trapFpe: Floating point exception trapping enabled (FOAM_SIGFPE).
memory pool : not available
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 5, maxFileModificationPolls 20)
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

--> FOAM Warning : 
    From bool Foam::IOobject::readHeader(Foam::dictionary&, Foam::Istream&)
    in file db/IOobject/IOobjectReadHeader.C at line 118
    Reading "system/controlD
```

### tool: bash

`cat -n /work/20260507-080356-73d0/case/system/controlDict | sed -n '1,50p'` exit 0

**input**

```
{
  "cmd": "cat -n /work/20260507-080356-73d0/case/system/controlDict | sed -n '1,50p'"
}
```

**output**

```
exit_code: 0

     1	/*--------------------------------*- C++ -*----------------------------------*\
     2	FoamFile
     3	{
     4	    version     2.0;
     5	    format      ascii;
     6	    class       dictionary;
     7	    object      controlDict;
     8	}
     9	// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
    10	
    11	application     chtMultiRegionSimpleFoam;
    12	
    13	startFrom       startTime;
    14	
    15	startTime       0;
    16	
    17	stopAt          endTime;
    18	
    19	endTime         1500;
    20	
    21	deltaT          1;
    22	
    23	writeControl    timeStep;
    24	
    25	writeInterval   100;
    26	
    27	purgeWrite      2;
    28	
    29	writeFormat     ascii;
    30	
    31	writePrecision  7;
    32	
    33	writeCompression off;
    34	
    35	timeFormat      general;
    36	
    37	timePrecision   6;
    38	
    39	runTimeModifiable true;
    40	
    41	functions
    42	{
    43	}
    44	
    45	// ************************************************************************* //
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\ngrep -rl '^/\\*-.*-\\*\\\\$' --include=\"*\" . | while read f; do\n  if ! head -8 \"$f\" | grep -q '\\\\*---.*---\\*/'; then\n    echo \"FIX: $f\"\n  fi\ndone"
}
```

**output**

```
exit_code: 0

FIX: ./0.orig/T
FIX: ./0.orig/U
FIX: ./0.orig/epsilon
FIX: ./0.orig/k
FIX: ./0.orig/p
FIX: ./0.orig/p_rgh
FIX: ./constant/fluid/radiationProperties
FIX: ./constant/fluid/thermophysicalProperties
FIX: ./constant/fluid/turbulenceProperties
FIX: ./constant/g
FIX: ./constant/regionProperties
FIX: ./constant/solid/radiationProperties
FIX: ./constant/solid/thermophysicalProperties
FIX: ./system/blockMeshDict
FIX: ./system/controlDict
FIX: ./system/fluid/changeDictionaryDict
FIX: ./system/fluid/fvSchemes
FIX: ./system/fluid/fvSolution
FIX: ./system/fvSchemes
FIX: ./system/fvSolution
FIX: ./system/solid/changeDictionaryDict
FIX: ./system/solid/fvSchemes
FIX: ./system/solid/fvSolution
FIX: ./system/topoSetDict
```

### agent

All of them need the fix. Let me patch every file by inserting the closing comment line right before `FoamFile`.

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\nfiles=$(grep -rl '^/\\*-.*-\\*\\\\$' --include=\"*\" .)\nfor f in $files; do\n  python3 - \"$f\" << 'EOF'\nimport sys\np=sys.argv[1]\ns=open(p).read()\nmarker=\"\\\\*---------------------------------------------------------------------------*/\\n\"\ns2 = s.replace(\"FoamFile\\n\", marker+\"FoamFile\\n\", 1)\nopen(p,\"w\").write(s2)\nEOF\ndone\nhead -10 system/controlDict"
}
```

**output**

```
exit_code: 0

/*--------------------------------*- C++ -*----------------------------------*\
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      controlDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
```

### agent

That should be a properly closed (if minimal) comment now. Let's test blockMesh.

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\nblockMesh 2>&1 | tail -40"
}
```

**output**

```
exit_code: 0
[took 20s]

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Creating block mesh from "system/blockMeshDict"

--> FOAM FATAL ERROR: (openfoam-2512)
Unknown functionEntry 'define' in "system/blockMeshDict" near line 19

Valid functionEntries :

19
(
calc
codeStream
default
error
if
ifeq
include
includeEtc
includeFunc
includeIfPresent
inputMode
merge
message
overwrite
remove
sinclude
sincludeEtc
warn
word
)

    From static bool Foam::functionEntry::execute(const Foam::word&, Foam::dictionary&, Foam::Istream&)
    in file db/dictionary/functionEntries/functionEntry/functionEntry.C at line 122.

FOAM exiting
```

### tool: write_file

`/work/20260507-080356-73d0/case/system/blockMeshDict`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/system/blockMeshDict",
  "content": "/*--------------------------------*- C++ -*----------------------------------*\\\n\\*---------------------------------------------------------------------------*/\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      blockMeshDict;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\n// Unit-cell heat sink model: one fin + half-channel on each side.\n// x: streamwise (fin/base length), y: pitch (fin thickness + channels),\n// z: base thickness + fin height.\n// x0=0.0 x1=0.04 ; y0=0.0 y1=0.005 ; z0=0.0 z1=0.003 z2=0.023\n\nscale 1;\n\nvertices\n(\n    ( 0.0  0.0   0.0   )   // 0\n    ( 0.04 0.0   0.0   )   // 1\n    ( 0.04 0.005 0.0   )   // 2\n    ( 0.0  0.005 0.0   )   // 3\n    ( 0.0  0.0   0.003 )   // 4\n    ( 0.04 0.0...
```

**output**

```
wrote 2006 bytes to /work/20260507-080356-73d0/case/system/blockMeshDict
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\nblockMesh 2>&1 | tail -50"
}
```

**output**

```
exit_code: 0

Check topology

	Basic statistics
		Number of internal faces : 1
		Number of boundary faces : 10
		Number of defined boundary faces : 10
		Number of undefined boundary faces : 0
	Checking patch -> block consistency

Creating block offsets
Creating merge list (topological search)...

Creating polyMesh from blockMesh
Creating patches
Creating cells
Creating points with scale (1 1 1)
    Block 0 cell size :
        i : 0.00125 .. 0.00125
        j : 0.00025 .. 0.00025
        k : 0.001 .. 0.001

    Block 1 cell size :
        i : 0.00125 .. 0.00125
        j : 0.00025 .. 0.00025
        k : 0.002 .. 0.002

No patch pairs to merge

Writing polyMesh with 0 cellZones
----------------
Mesh Information
----------------
  boundingBox: (0 0 0) (0.04 0.005 0.023)
  nPoints: 9702
  nCells: 8320
  nFaces: 26276
  nInternalFaces: 23644
----------------
Patches
----------------
  patch 0 (start: 23644 size: 260) name: inlet
  patch 1 (start: 23904 size: 260) name: outlet
  patch 2 (start: 24164 size: 416) name: sideMinY
  patch 3 (start: 24580 size: 416) name: sideMaxY
  patch 4 (start: 24996 size: 640) name: baseBottom
  patch 5 (start: 25636 size: 640) name: topOpen

End
```

### agent

Mesh built: 8320 cells as expected. Now topoSet, then checkMesh before proceeding further.

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\ntopoSet 2>&1 | tail -40"
}
```

**output**

```
exit_code: 0

trapFpe: Floating point exception trapping enabled (FOAM_SIGFPE).
memory pool : not available
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 5, maxFileModificationPolls 20)
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create polyMesh for time = 0

Reading topoSetDict

Time = 0
    mesh not changed.
Created cellSet solidCellSet
    Applying source boxToCell
    Adding cells with centre within boxes 1((-1 -1 -1) (1 1 0.0031))
    cellSet solidCellSet now size 1920
Read set cellSet solidCellSet size:1920
    Applying source boxToCell
    Adding cells with centre within boxes 1((-1 0.00174 0.0029) (1 0.00326 1))
    cellSet solidCellSet now size 3840
Created cellZoneSet solid
    Applying source setToCellZone
    Adding all cells from cell set: solidCellSet ...
    cellZoneSet solid now size 3840
Created cellSet fluidCellSet
    Applying source cellToCell
    Adding all elements of cell sets: (solidCellSet)
    cellSet fluidCellSet now size 3840
Read set cellSet fluidCellSet size:3840
    Inverting cellSet
    cellSet fluidCellSet now size 4480
Created cellZoneSet fluid
    Applying source setToCellZone
    Adding all cells from cell set: fluidCellSet ...
    cellZoneSet fluid now size 4480

E
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\nrestore0Dir 2>&1 | tail -20\nls 0\nsplitMeshRegions -cellZones -overwrite 2>&1 | tail -60"
}
```

**output**

```
exit_code: 0

bash: line 5: restore0Dir: command not found
ls: cannot access '0': No such file or directory

Reading volScalarField: cellToRegion

Adding patches

Adding patches

For interface between region solid and domain1 added patches
    6	solid_to_domain1
    7	domain1_to_solid
For interface between region solid and domain2 added patches
    8	solid_to_domain2
    9	domain2_to_solid

Region 0
-------- 
Creating mesh for region 0 solid
Mapping fields
Mapping field cellToRegion
Deleting empty patches
Writing new mesh
Writing addressing to base mesh
Writing map pointRegionAddressing from region0 points back to base mesh.
Writing map faceRegionAddressing from region0 faces back to base mesh.
Writing map cellRegionAddressing from region0 cells back to base mesh.
Writing map boundaryRegionAddressing from region0 boundary back to base mesh.

Region 1
-------- 
Creating mesh for region 1 domain1
Writing dummy "domain1/fvSchemes"
Writing dummy "domain1/fvSolution"
Mapping fields
Mapping field cellToRegion
Deleting empty patches
Writing new mesh
Writing addressing to base mesh
Writing map pointRegionAddressing from region1 points back to base mesh.
Writing map faceRegionAddressing from region1 faces back to base mesh.
Writing map cellRegionAddressing from region1 cells back to base mesh.
Writing map boundaryRegionAddressing from region1 boundary back to base mesh.

Region 2
----
```

### tool: bash

`splitMeshRegions -help 2>&1 | head -60` exit 0

**input**

```
{
  "cmd": "splitMeshRegions -help 2>&1 | head -60"
}
```

**output**

```
exit_code: 0

Usage: splitMeshRegions [OPTIONS]
Options:
  -addZones <lists of zones>
                    Combine zones in follow-on analysis
  -blockedFaces <faceSet>
                    Specify additional region boundaries that walking does not
                    cross
  -case <dir>       Case directory (instead of current directory)
  -cellZones        Additionally split cellZones off into separate regions
  -cellZonesFileOnly <file>
                    Like -cellZonesOnly, but use specified file
  -cellZonesOnly    Use cellZones only to split mesh into regions; do not use
                    walking
  -combineZones <lists of zones>
                    Combine zones in follow-on analysis
  -decomposeParDict <file>
                    Alternative decomposePar dictionary file
  -detectOnly       Do not write mesh
  -insidePoint <point>
                    Only write region containing point
  -largestOnly      Only write largest region
  -makeCellZones    Place cells into cellZones instead of splitting mesh
  -overwrite        Overwrite existing mesh/results files
  -parallel         Run in parallel
  -prefixRegion     Prefix region name to all patches, not just coupling patches
  -region <name>    Specify mesh region (default: region0)
  -sloppyCellZones  Try to match heuristically regions to existing cell zones
  -useFaceZones     Use faceZones to patch inter-region faces i
```

### agent

I need `-cellZonesOnly` instead of `-cellZones` (which additionally does connectivity-based splitting). Let me redo.

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\nrm -rf constant/solid constant/domain1 constant/domain2 constant/fluid 0 processor* 2>/dev/null\n# restore original single-region constant dir structure (need thermophysical etc only in solid/fluid which we already wrote separately; splitMeshRegions with -cellZonesOnly will just create region meshes named after zone names \"solid\",\"fluid\")\nls constant\n"
}
```

**output**

```
exit_code: 0

cellToRegion
g
polyMesh
regionProperties
```

### tool: bash

`ls /work/20260507-080356-73d0/case/system/fluid /work/20260507-080356-73d0/cas...` exit 0

**input**

```
{
  "cmd": "ls /work/20260507-080356-73d0/case/system/fluid /work/20260507-080356-73d0/case/system/solid"
}
```

**output**

```
exit_code: 0
[took 12s]

/work/20260507-080356-73d0/case/system/fluid:
changeDictionaryDict
fvSchemes
fvSolution

/work/20260507-080356-73d0/case/system/solid:
changeDictionaryDict
fvSchemes
fvSolution
```

### agent

Good, system/ is intact. Let me recreate constant/fluid and constant/solid.

### tool: bash

`mkdir -p /work/20260507-080356-73d0/case/constant/fluid /work/20260829-080356-...` exit 0

**input**

```
{
  "cmd": "mkdir -p /work/20260507-080356-73d0/case/constant/fluid /work/20260507-080356-73d0/case/constant/solid"
}
```

**output**

```
exit_code: 0
```

### tool: write_file

`/work/20260507-080356-73d0/case/constant/fluid/thermophysicalProperties`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/constant/fluid/thermophysicalProperties",
  "content": "/*--------------------------------*- C++ -*----------------------------------*\\\n\\*---------------------------------------------------------------------------*/\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      thermophysicalProperties;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\nthermoType\n{\n    type            heRhoThermo;\n    mixture         pureMixture;\n    transport       const;\n    thermo          hConst;\n    equationOfState rhoConst;\n    specie          specie;\n    energy          sensibleEnthalpy;\n}\n\nmixture\n{\n    specie\n    {\n        molWeight       28.9;\n    }\n    equationOfState\n    {\n        rho             1.2;\n    }\n    thermodynamics\n    {\n        Cp...
```

**output**

```
wrote 986 bytes to /work/20260507-080356-73d0/case/constant/fluid/thermophysicalProperties
```

### tool: write_file

`/work/20260507-080356-73d0/case/constant/fluid/turbulenceProperties`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/constant/fluid/turbulenceProperties",
  "content": "/*--------------------------------*- C++ -*----------------------------------*\\\n\\*---------------------------------------------------------------------------*/\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      turbulenceProperties;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\nsimulationType  laminar;\n\n// ************************************************************************* //\n"
}
```

**output**

```
wrote 470 bytes to /work/20260507-080356-73d0/case/constant/fluid/turbulenceProperties
```

### tool: write_file

`/work/20260507-080356-73d0/case/constant/fluid/radiationProperties`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/constant/fluid/radiationProperties",
  "content": "/*--------------------------------*- C++ -*----------------------------------*\\\n\\*---------------------------------------------------------------------------*/\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      radiationProperties;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\nradiation off;\nradiationModel none;\n\n// ************************************************************************* //\n"
}
```

**output**

```
wrote 480 bytes to /work/20260507-080356-73d0/case/constant/fluid/radiationProperties
```

### tool: write_file

`/work/20260507-080356-73d0/case/constant/solid/thermophysicalProperties`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/constant/solid/thermophysicalProperties",
  "content": "/*--------------------------------*- C++ -*----------------------------------*\\\n\\*---------------------------------------------------------------------------*/\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      thermophysicalProperties;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\nthermoType\n{\n    type            heSolidThermo;\n    mixture         pureMixture;\n    transport       constIso;\n    thermo          hConst;\n    equationOfState rhoConst;\n    specie          specie;\n    energy          sensibleEnthalpy;\n}\n\nmixture\n{\n    specie\n    {\n        molWeight   26.98;\n    }\n    transport\n    {\n        kappa   205;\n    }\n    thermodynamics\n    {\n        Hf      0;\n...
```

**output**

```
wrote 921 bytes to /work/20260507-080356-73d0/case/constant/solid/thermophysicalProperties
```

### tool: write_file

`/work/20260507-080356-73d0/case/constant/solid/radiationProperties`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/constant/solid/radiationProperties",
  "content": "/*--------------------------------*- C++ -*----------------------------------*\\\n\\*---------------------------------------------------------------------------*/\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      radiationProperties;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\nradiation off;\nradiationModel none;\n\n// ************************************************************************* //\n"
}
```

**output**

```
wrote 480 bytes to /work/20260507-080356-73d0/case/constant/solid/radiationProperties
```

### agent

Now let's rebuild the mesh from scratch and redo the region split properly with `-cellZonesOnly`.

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 1

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\nrm -rf constant/polyMesh constant/cellToRegion 0\nblockMesh > log.blockMesh 2>&1 && tail -5 log.blockMesh\ntopoSet > log.topoSet 2>&1 && tail -5 log.topoSet\nwhich restore0Dir foamListRegions remove0DirFields"
}
```

**output**

```
exit_code: 1

  patch 4 (start: 24996 size: 640) name: baseBottom
  patch 5 (start: 25636 size: 640) name: topOpen

End

    Adding all cells from cell set: fluidCellSet ...
    cellZoneSet fluid now size 4480

End

/usr/lib/openfoam/openfoam2512/platforms/linux64GccDPInt32Opt/bin/foamListRegions
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\n. ${WM_PROJECT_DIR}/bin/tools/RunFunctions\ncp -r 0.orig 0\nsplitMeshRegions -cellZonesOnly -overwrite > log.split 2>&1\ntail -60 log.split"
}
```

**output**

```
exit_code: 0

Build  : _87ed40d2-20251219 OPENFOAM=2512 version=2512
Arch   : "LSB;label=32;scalar=64"
Exec   : splitMeshRegions -cellZonesOnly -overwrite
Date   : Aug 29 2026
Time   : 00:26:11
Host   : modal
PID    : 61235
I/O    : uncollated
Case   : /work/20260507-080356-73d0/case
nProcs : 1
trapFpe: Floating point exception trapping enabled (FOAM_SIGFPE).
memory pool : not available
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 5, maxFileModificationPolls 20)
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create mesh for time = 0

Creating single patch per inter-region interface.

Using current cellZones to split mesh into regions. This requires all cells to be in one and only one cellZone.

Number of regions:2

Writing region per cell file (for manual decomposition) to "/work/20260507-080356-73d0/case/constant/cellToRegion"

Writing region per cell as volScalarField to "/work/20260507-080356-73d0/case/0/cellToRegion"

Region	Cells
------	-----
0	3840
1	4480

Region	Zone	Name
------	----	----
0	(0)	solid
1	(1)	fluid

Sizes of interfaces between regions:

Interface	Region	Region	Faces
---------	------	------	-----
0		0	1	1088

Reading volScalarField: T

--> FOAM FATAL IO ERROR: (openfoam-2512)
incons
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\nfor f in 0.orig/T 0.orig/U 0.orig/p 0.orig/p_rgh 0.orig/k 0.orig/epsilon; do\npython3 - \"$f\" << 'EOF'\nimport sys\np=sys.argv[1]\ns=open(p).read()\nins = '''        sideMinY\n        {\n            type            symmetryPlane;\n        }\n        sideMaxY\n        {\n            type            symmetryPlane;\n        }\n'''\ns2 = s.replace(\"boundaryField\\n{\\n\", \"boundaryField\\n{\\n\"+ins, 1)\nopen(p,\"w\").write(s2)\nEOF\ndone\ncat 0.orig/T"
}
```

**output**

```
exit_code: 0

/*--------------------------------*- C++ -*----------------------------------*\
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    object      T;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 0 0 1 0 0 0];

internalField   uniform 298.15;

boundaryField
{
        sideMinY
        {
            type            symmetryPlane;
        }
        sideMaxY
        {
            type            symmetryPlane;
        }
    ".*"
    {
        type            calculated;
        value           $internalField;
    }
}

// ************************************************************************* //
```

### agent

Now redo the split from scratch.

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\nrm -rf 0 processor* constant/solid/polyMesh constant/fluid/polyMesh constant/cellToRegion\ncp -r 0.orig 0\nsplitMeshRegions -cellZonesOnly -overwrite > log.split 2>&1\ntail -40 log.split"
}
```

**output**

```
exit_code: 0

Region 0
-------- 
Creating mesh for region 0 solid
Mapping fields
Mapping field T
Mapping field cellToRegion
Mapping field epsilon
Mapping field k
Mapping field p
Mapping field p_rgh
Mapping field U
Deleting empty patches
Writing new mesh
Writing addressing to base mesh
Writing map pointRegionAddressing from region0 points back to base mesh.
Writing map faceRegionAddressing from region0 faces back to base mesh.
Writing map cellRegionAddressing from region0 cells back to base mesh.
Writing map boundaryRegionAddressing from region0 boundary back to base mesh.

Region 1
-------- 
Creating mesh for region 1 fluid
Mapping fields
Mapping field T
Mapping field cellToRegion
Mapping field epsilon
Mapping field k
Mapping field p
Mapping field p_rgh
Mapping field U
Deleting empty patches
Writing new mesh
Writing addressing to base mesh
Writing map pointRegionAddressing from region1 points back to base mesh.
Writing map faceRegionAddressing from region1 faces back to base mesh.
Writing map cellRegionAddressing from region1 cells back to base mesh.
Writing map boundaryRegionAddressing from region1 boundary back to base mesh.
End
```

### agent

Split succeeded. Now remove fluid-only fields from the solid region, then apply changeDictionary per region.

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\n. ${WM_PROJECT_DIR}/bin/tools/RunFunctions\nfoamListRegions\necho ---\nfoamListRegions solid\nls 0/solid 0/fluid"
}
```

**output**

```
exit_code: 0
[took 46s]

fluid
solid
---
solid
0/fluid:
T
U
cellToRegion
epsilon
k
p
p_rgh

0/solid:
T
U
cellToRegion
epsilon
k
p
p_rgh
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\nrm -f 0/solid/U 0/solid/p 0/solid/p_rgh 0/solid/k 0/solid/epsilon 0/solid/cellToRegion 0/fluid/cellToRegion\nls 0/solid 0/fluid"
}
```

**output**

```
exit_code: 0

0/fluid:
T
U
epsilon
k
p
p_rgh

0/solid:
T
```

### agent

Now apply changeDictionary for each region.

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\nchangeDictionary -region fluid > log.changeDict.fluid 2>&1; tail -30 log.changeDict.fluid"
}
```

**output**

```
exit_code: 0

Merging entries from 2(internalField boundaryField)
Writing modified fieldDict U
Replacing entries in dictionary T
Loading dictionary T
Loaded dictionary T with entries 3(dimensions internalField boundaryField)
Merging entries from 2(internalField boundaryField)
Writing modified fieldDict T
Replacing entries in dictionary p_rgh
Loading dictionary p_rgh
Loaded dictionary p_rgh with entries 3(dimensions internalField boundaryField)
Merging entries from 2(internalField boundaryField)
Writing modified fieldDict p_rgh
Replacing entries in dictionary p
Loading dictionary p
Loaded dictionary p with entries 3(dimensions internalField boundaryField)
Merging entries from 2(internalField boundaryField)
Writing modified fieldDict p
Replacing entries in dictionary k
Loading dictionary k
Loaded dictionary k with entries 3(dimensions internalField boundaryField)
Merging entries from 2(internalField boundaryField)
Writing modified fieldDict k
Replacing entries in dictionary epsilon
Loading dictionary epsilon
Loaded dictionary epsilon with entries 3(dimensions internalField boundaryField)
Merging entries from 2(internalField boundaryField)
Writing modified fieldDict epsilon

End
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\nchangeDictionary -region solid > log.changeDict.solid 2>&1; tail -30 log.changeDict.solid"
}
```

**output**

```
exit_code: 0

        startFace       10776;
    }
    topOpen
    {
        type            wall;
        inGroups        1 ( wall );
        nFaces          192;
        startFace       11416;
    }
    solid_to_fluid
    {
        type            mappedWall;
        inGroups        1 ( wall );
        nFaces          1088;
        startFace       11608;
        sampleMode      nearestPatchFace;
        sampleRegion    fluid;
        samplePatch     fluid_to_solid;
    }
}

Writing modified boundary
Replacing entries in dictionary T
Loading dictionary T
Loaded dictionary T with entries 3(dimensions internalField boundaryField)
Merging entries from 2(internalField boundaryField)
Writing modified fieldDict T

End
```

### agent

Both regions processed cleanly. Let's check the boundary field content applied correctly and check patch names match my regex `.*_to_.*`.

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\ncat 0/solid/T\necho ===FLUID T===\ncat 0/fluid/T | head -60"
}
```

**output**

```
exit_code: 0

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2512                                  |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    arch        "LSB;label=32;scalar=64";
    class       volScalarField;
    location    "0/solid";
    object      T;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [ 0 0 0 1 0 0 0 ];

internalField   uniform 310;

boundaryField
{
    inlet
    {
        type            zeroGradient;
        value           uniform 310;
    }
    outlet
    {
        type            zeroGradient;
        value           uniform 310;
    }
    sideMinY
    {
        type            symmetryPlane;
    }
    sideMaxY
    {
        type            symmetryPlane;
    }
    baseBottom
    {
        type            externalWallHeatFluxTemperature;
        value           uniform 310;
        mode            power;
        Q
```

### tool: write_file

`/work/20260507-080356-73d0/case/system/solid/changeDictionaryDict`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/system/solid/changeDictionaryDict",
  "content": "/*--------------------------------*- C++ -*----------------------------------*\\\n\\*---------------------------------------------------------------------------*/\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      changeDictionaryDict;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\nboundary\n{\n    sideMinY\n    {\n        type            symmetryPlane;\n    }\n    sideMaxY\n    {\n        type            symmetryPlane;\n    }\n}\n\nT\n{\n    internalField   uniform 310;\n\n    boundaryField\n    {\n        \".*\"\n        {\n            type            zeroGradient;\n            value           uniform 310;\n        }\n        sideMinY\n        {\n            type            symmetryPlane;\n        }\...
```

**output**

```
wrote 1419 bytes to /work/20260507-080356-73d0/case/system/solid/changeDictionaryDict
```

### agent

Now reorder the fluid one similarly (put the coupling pattern last).

### tool: write_file

`/work/20260507-080356-73d0/case/system/fluid/changeDictionaryDict`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/system/fluid/changeDictionaryDict",
  "content": "/*--------------------------------*- C++ -*----------------------------------*\\\n\\*---------------------------------------------------------------------------*/\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      changeDictionaryDict;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\nboundary\n{\n    sideMinY\n    {\n        type            symmetryPlane;\n    }\n    sideMaxY\n    {\n        type            symmetryPlane;\n    }\n}\n\nU\n{\n    internalField   uniform (2 0 0);\n\n    boundaryField\n    {\n        \".*\"\n        {\n            type            fixedValue;\n            value           uniform (0 0 0);\n        }\n        inlet\n        {\n            type            fixedValue;\n...
```

**output**

```
wrote 3701 bytes to /work/20260507-080356-73d0/case/system/fluid/changeDictionaryDict
```

### agent

Now rebuild fully from scratch and re-verify.

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\nrm -rf 0 processor* constant/solid/polyMesh constant/fluid/polyMesh constant/cellToRegion constant/polyMesh log.*\n. ${WM_PROJECT_DIR}/bin/tools/RunFunctions\nblockMesh > log.blockMesh 2>&1\ntopoSet > log.topoSet 2>&1\ncp -r 0.orig 0\nsplitMeshRegions -cellZonesOnly -overwrite > log.split 2>&1\ntail -5 log.split\nrm -f 0/solid/U 0/solid/p 0/solid/p_rgh 0/solid/k 0/solid/epsilon 0/solid/cellToRegion 0/fluid/cellToRegion\nchangeDictionary -region fluid > log.changeDict.fluid 2>&1; tail -5 log.changeDict.fluid\nchangeDictionary -region solid > log.changeDict.solid 2>&1; tail -5 log.changeDict.solid\necho \"=== solid T ===\"; cat 0/solid/T\necho \"=== fluid T ===\"; cat 0/fluid/T"
}
```

**output**

```
exit_code: 0

Writing map faceRegionAddressing from region1 faces back to base mesh.
Writing map cellRegionAddressing from region1 cells back to base mesh.
Writing map boundaryRegionAddressing from region1 boundary back to base mesh.
End

Merging entries from 2(internalField boundaryField)
Writing modified fieldDict epsilon

End

Merging entries from 2(internalField boundaryField)
Writing modified fieldDict T

End

=== solid T ===
/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2512                                  |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    arch        "LSB;label=32;scalar=64";
    class       volScalarField;
    location    "0/solid";
    object      T;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [ 0 0 0 1 0 0 0 ];

internalField   uniform 310;

boundaryField
{
    inlet
    {
        type            zeroGradient;
        val
```

### agent

Now correct on both regions. Let's check U, p, p_rgh for fluid too, then run checkMesh and render before solving.

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\ncat 0/fluid/U\necho ===p_rgh===; cat 0/fluid/p_rgh"
}
```

**output**

```
exit_code: 0

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2512                                  |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    arch        "LSB;label=32;scalar=64";
    class       volVectorField;
    location    "0/fluid";
    object      U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [ 0 1 -1 0 0 0 0 ];

internalField   uniform ( 2 0 0 );

boundaryField
{
    inlet
    {
        type            fixedValue;
        value           uniform ( 2 0 0 );
    }
    outlet
    {
        type            inletOutlet;
        value           uniform ( 2 0 0 );
        inletValue      uniform ( 0 0 0 );
    }
    sideMinY
    {
        type            symmetryPlane;
    }
    sideMaxY
    {
        type            symmetryPlane;
    }
    topOpen
    {
        type            fixedValue;
        value           uniform ( 0 0 0 );
    }
```

### agent

All good. Now checkMesh on both regions, then render.

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\ncheckMesh -region fluid > log.checkMesh.fluid 2>&1; tail -60 log.checkMesh.fluid"
}
```

**output**

```
exit_code: 0

    prisms:        0
    wedges:        0
    pyramids:      0
    tet wedges:    0
    tetrahedra:    0
    polyhedra:     0

Checking topology...
    Boundary definition OK.
    Cell to face addressing OK.
    Point usage OK.
    Upper triangular ordering OK.
    Face vertices OK.
   *Number of regions: 2
    The mesh has multiple regions which are not connected by any face.
  <<Writing region information to "0/cellToRegion"
  <<Writing region 0 with 2240 cells to cellSet region0
  <<Writing region 1 with 2240 cells to cellSet region1

Checking patch topology for multiply connected surfaces...
    Patch               Faces    Points     Surface topology
    inlet               140      176      ok (non-closed singly connected)  
    outlet              140      176      ok (non-closed singly connected)  
    sideMinY            320      363      ok (non-closed singly connected)  
    sideMaxY            320      363      ok (non-closed singly connected)  
    topOpen             448      528      ok (non-closed singly connected)  
    fluid_to_solid      1088     1188     ok (non-closed singly connected)  
    ".*"                2456     2460     ok (closed singly connected)      

Checking faceZone topology for multiply connected surfaces...
    No faceZones found.

Checking basic cellZone addressing...
    CellZone            Cells        Points       Volume
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\ncheckMesh -region solid > log.checkMesh.solid 2>&1; tail -50 log.checkMesh.solid"
}
```

**output**

```
exit_code: 0

Checking topology...
    Boundary definition OK.
    Cell to face addressing OK.
    Point usage OK.
    Upper triangular ordering OK.
    Face vertices OK.
    Number of regions: 1 (OK).

Checking patch topology for multiply connected surfaces...
    Patch               Faces    Points     Surface topology
    inlet               120      154      ok (non-closed singly connected)  
    outlet              120      154      ok (non-closed singly connected)  
    sideMinY            96       132      ok (non-closed singly connected)  
    sideMaxY            96       132      ok (non-closed singly connected)  
    baseBottom          640      693      ok (non-closed singly connected)  
    topOpen             192      231      ok (non-closed singly connected)  
    solid_to_fluid      1088     1188     ok (non-closed singly connected)  
    ".*"                2352     2354     ok (closed singly connected)      

Checking faceZone topology for multiply connected surfaces...
    No faceZones found.

Checking basic cellZone addressing...
    CellZone            Cells        Points       Volume       BoundingBox
    solid               3840         5082         1.8e-06      (0 0 0) (0.04 0.005 0.023)
    fluid               0            0            0            (1e+150 1e+150 1e+150) (-1e+150 -1e+150 -1e+150)

Checking basic pointZone addressing...
    No pointZones
```

### agent

Both regions clean (perfectly orthogonal, aspect ratio 8, mesh OK). Now render geometry/mesh views before running the solve.

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\ntouch case.foam 2>/dev/null\npython3 /work/.toolbox/render.py . --scene mesh --normal y --out renders 2>&1 | tail -30\npython3 /work/.toolbox/render.py . --scene mesh --normal x --out renders 2>&1 | tail -30\npython3 /work/.toolbox/render.py . --scene mesh --normal z --out renders 2>&1 | tail -30\nls renders"
}
```

**output**

```
exit_code: 0
[took 47s]

time 0  (available: 0)
cells 8,320  points 9,702
renders/mesh_y.png
time 0  (available: 0)
cells 8,320  points 9,702
renders/mesh_x.png
2026-08-29 00:29:41.315 (   0.793s) [    2AC27B0FF540]        vtkRenderer.cxx:1161  WARN| vtkOpenGLRenderer (0x25c9a40): Resetting view-up since view plane normal is parallel
time 0  (available: 0)
cells 8,320  points 9,702
renders/mesh_z.png
mesh_x.png
mesh_y.png
mesh_z.png
```

### tool: read_file

`/work/20260507-080356-73d0/case/renders/mesh_y.png`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/renders/mesh_y.png"
}
```

**output**

```
[image/png, 33861 bytes]
/work/20260507-080356-73d0/case/renders/mesh_y.png — 1100x800 image/png, 33860 bytes
```

### tool: bash

`ls /work/20260507-080356-73d0/case/constant/` exit 0

**input**

```
{
  "cmd": "ls /work/20260507-080356-73d0/case/constant/\nls /work/20260507-080356-73d0/case/constant/polyMesh 2>/dev/null | head\nls /work/20260507-080356-73d0/case/constant/fluid/polyMesh | head\nls /work/20260507-080356-73d0/case/constant/solid/polyMesh | head"
}
```

**output**

```
exit_code: 0

cellToRegion
fluid
g
polyMesh
regionProperties
solid
boundary
cellZones
faces
neighbour
owner
points
sets
boundary
boundaryRegionAddressing
cellRegionAddressing
cellZones
faceRegionAddressing
faceZones
faces
neighbour
owner
pointRegionAddressing
boundary
boundaryRegionAddressing
cellRegionAddressing
cellZones
faceRegionAddressing
faceZones
faces
neighbour
owner
pointRegionAddressing
```

### tool: bash

`grep -n "region\|add_argument" /work/.toolbox/render.py | head -30` exit 0

**input**

```
{
  "cmd": "grep -n \"region\\|add_argument\" /work/.toolbox/render.py | head -30"
}
```

**output**

```
exit_code: 0

110:    parser.add_argument("case", type=Path)
111:    parser.add_argument("--out", type=Path, default=None, help="defaults to <case>/renders")
112:    parser.add_argument("--fields", nargs="*", default=["U", "p"])
113:    parser.add_argument("--normal", default="z", choices=sorted(NORMALS))
114:    parser.add_argument("--time", type=float, default=None)
115:    parser.add_argument("--scene", default="all", choices=["all", "mesh", "fields"])
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\nfoamToVTK -region fluid -time 0 > log.vtk.fluid 2>&1; tail -20 log.vtk.fluid\nfoamToVTK -region solid -time 0 > log.vtk.solid 2>&1; tail -20 log.vtk.solid\nfind VTK -iname \"*.vtu\" -o -iname \"*.vtk\""
}
```

**output**

```
exit_code: 0

Create time

Initial memory 133160 kB
Create mesh for time = 0

VTK mesh topology: 0.03 s, 135120 kB
Time: 0
    volScalar    : T epsilon k p p_rgh
    volVector    : U
    Internal  : "VTK/fluid/case_0/internal.vtu"
    Boundary  : "VTK/fluid/case_0/boundary/inlet.vtp"
    Boundary  : "VTK/fluid/case_0/boundary/outlet.vtp"
    Boundary  : "VTK/fluid/case_0/boundary/sideMinY.vtp"
    Boundary  : "VTK/fluid/case_0/boundary/sideMaxY.vtp"
    Boundary  : "VTK/fluid/case_0/boundary/topOpen.vtp"
    Boundary  : "VTK/fluid/case_0/boundary/fluid_to_solid.vtp"
Wrote in 0.05 s, 138256 kB

End: 0.08 s, 0 kB (peak)

Create time

Initial memory 133160 kB
Create mesh for time = 0

VTK mesh topology: 0.03 s, 134848 kB
Time: 0
    volScalar    : T
    Internal  : "VTK/solid/case_0/internal.vtu"
    Boundary  : "VTK/solid/case_0/boundary/inlet.vtp"
    Boundary  : "VTK/solid/case_0/boundary/outlet.vtp"
    Boundary  : "VTK/solid/case_0/boundary/sideMinY.vtp"
    Boundary  : "VTK/solid/case_0/boundary/sideMaxY.vtp"
    Boundary  : "VTK/solid/case_0/boundary/baseBottom.vtp"
    Boundary  : "VTK/solid/case_0/boundary/topOpen.vtp"
    Boundary  : "VTK/solid/case_0/boundary/solid_to_fluid.vtp"
Wrote in 0.04 s, 137124 kB

End: 0.07 s, 0 kB (peak)

VTK/fluid/case_0/internal.vtu
VTK/solid/case_0/internal.vtu
```

### agent

Now let's write a small custom pyvista script that shows both regions (solid=aluminum, fluid=air) together, sliced.

### tool: write_file

`/work/20260507-080356-73d0/case/renders/make_region_views.py`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/renders/make_region_views.py",
  "content": "import pyvista as pv\nimport numpy as np\npv.OFF_SCREEN = True\n\nfluid = pv.read(\"VTK/fluid/case_0/internal.vtu\")\nsolid = pv.read(\"VTK/solid/case_0/internal.vtu\")\n\ndef render(normal, origin_frac, fname, title):\n    bounds = np.array(fluid.merge(solid).bounds).reshape(3,2).mean(axis=1) if False else None\n    plotter = pv.Plotter(off_screen=True, window_size=(1300, 800))\n    plotter.add_mesh(solid, color=\"lightsteelblue\", show_edges=True, edge_color=\"black\", line_width=0.5, label=\"aluminium (solid)\")\n    plotter.add_mesh(fluid, color=\"salmon\", show_edges=True, edge_color=\"black\", line_width=0.5, label=\"air (fluid)\")\n    plotter.add_legend()\n    plotter.add_text(title, font_size=10)\n    if normal == \"iso\":\n        plotter.view_isometric()\n    else:\n        plotter.view_v...
```

**output**

```
wrote 1916 bytes to /work/20260507-080356-73d0/case/renders/make_region_views.py
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\npython3 renders/make_region_views.py 2>&1 | tail -30\nls renders"
}
```

**output**

```
exit_code: 0

done
make_region_views.py
mesh_x.png
mesh_xz_slice.png
mesh_y.png
mesh_yz_slice.png
mesh_z.png
regions_iso.png
```

### tool: read_file

`/work/20260507-080356-73d0/case/renders/regions_iso.png`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/renders/regions_iso.png"
}
```

**output**

```
[image/png, 280197 bytes]
/work/20260507-080356-73d0/case/renders/regions_iso.png — 1300x800 image/png, 280196 bytes
```

### tool: read_file

`/work/20260507-080356-73d0/case/renders/mesh_xz_slice.png`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/renders/mesh_xz_slice.png"
}
```

**output**

```
[image/png, 26739 bytes]
/work/20260507-080356-73d0/case/renders/mesh_xz_slice.png — 1300x500 image/png, 26738 bytes
```

### tool: read_file

`/work/20260507-080356-73d0/case/renders/mesh_yz_slice.png`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/renders/mesh_yz_slice.png"
}
```

**output**

```
[image/png, 37587 bytes]
/work/20260507-080356-73d0/case/renders/mesh_yz_slice.png — 900x900 image/png, 37585 bytes
```

### tool: write_file

`/work/20260507-080356-73d0/case/renders/make_region_views2.py`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/renders/make_region_views2.py",
  "content": "import pyvista as pv\npv.OFF_SCREEN = True\n\nfluid = pv.read(\"VTK/fluid/case_0/internal.vtu\")\nsolid = pv.read(\"VTK/solid/case_0/internal.vtu\")\n\n# y-z cross-section (fin+channels) at mid x, colour by region\nxmid = 0.5*(fluid.bounds[0]+fluid.bounds[1])\nfcut = fluid.slice(normal=(1,0,0), origin=(xmid,0,0))\nscut = solid.slice(normal=(1,0,0), origin=(xmid,0,0))\n\nplotter = pv.Plotter(off_screen=True, window_size=(900, 900))\nplotter.add_mesh(scut, color=\"lightsteelblue\", show_edges=True, edge_color=\"black\", line_width=0.6, label=\"aluminium\")\nplotter.add_mesh(fcut, color=\"salmon\", show_edges=True, edge_color=\"black\", line_width=0.6, label=\"air\")\nplotter.add_legend()\nplotter.view_vector((1,0,0))\nplotter.add_text(\"mesh - y-z cross-section at mid-length (fin + 2 half-channels)\"...
```

**output**

```
wrote 2350 bytes to /work/20260507-080356-73d0/case/renders/make_region_views2.py
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\npython3 renders/make_region_views2.py 2>&1 | tail -30\nls renders"
}
```

**output**

```
exit_code: 0

done
make_region_views.py
make_region_views2.py
mesh_x.png
mesh_xz_channel.png
mesh_xz_fin.png
mesh_xz_slice.png
mesh_y.png
mesh_yz_regions.png
mesh_yz_slice.png
mesh_z.png
regions_iso.png
```

### tool: read_file

`/work/20260507-080356-73d0/case/renders/mesh_yz_regions.png`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/renders/mesh_yz_regions.png"
}
```

**output**

```
[image/png, 38049 bytes]
/work/20260507-080356-73d0/case/renders/mesh_yz_regions.png — 900x900 image/png, 38047 bytes
```

### agent

This confirms the geometry is exactly as intended: base plate (blue, bottom 3 rows) spanning full width, fin (blue, centre column, 6 cells wide) rising through the channel height, with air channels (red) on either side. Let's check the other two slices quickly.

### tool: read_file

`/work/20260507-080356-73d0/case/renders/mesh_xz_channel.png`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/renders/mesh_xz_channel.png"
}
```

**output**

```
[image/png, 28887 bytes]
/work/20260507-080356-73d0/case/renders/mesh_xz_channel.png — 1300x500 image/png, 28887 bytes
```

### agent

Exactly as intended: 32×3 base cells (blue) with 32×10 channel cells (red) above, uniform structured grading, aspect ratio ~8:1 in the fin block (2mm×0.25mm), consistent with checkMesh's reported max aspect ratio of 8. The mesh matches the design and both checkMesh runs came back clean. I'm satisfied this coarse mesh is fit for a quick-look CHT solve. Now let's run the solver.

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\nrm -rf VTK log.vtk.* renders/*.py __pycache__\nls"
}
```

**output**

```
exit_code: 0

0
0.orig
Allrun.pre
case.foam
constant
log.blockMesh
log.changeDict.fluid
log.changeDict.solid
log.checkMesh.fluid
log.checkMesh.solid
log.split
log.topoSet
renders
system
```

### tool: job_start

`chtMultiRegionSimpleFoam`

**input**

```
{
  "name": "chtsolve",
  "cmd": "chtMultiRegionSimpleFoam",
  "cwd": "/work/20260507-080356-73d0/case",
  "kill_on": [
    "FOAM FATAL",
    "Floating point exception"
  ]
}
```

**output**

```
started job 9152a050-623a-4acc-af5e-fdbdcf1753d5 (chtsolve)
```

### tool: job_check

`job_id=9152a050-623a-4acc-af5e-fdbdcf1753d5 wait_s=60`

**input**

```
{
  "job_id": "9152a050-623a-4acc-af5e-fdbdcf1753d5",
  "wait_s": 60
}
```

**output**

```
job 9152a050-623a-4acc-af5e-fdbdcf1753d5 name=chtsolve status=killed end_reason=kill_on_match log_size=1318 ran_for=7s
matched kill_on line: trapFpe: Floating point exception trapping enabled (FOAM_SIGFPE).
log: bytes 0–1318, eof=True

/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2512                                  |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : _87ed40d2-20251219 OPENFOAM=2512 version=2512
Arch   : "LSB;label=32;scalar=64"
Exec   : chtMultiRegionSimpleFoam
Date   : Aug 29 2026
Time   : 00:33:28
Host   : modal
PID    : 14396
I/O    : uncollated
Case   : /work/20260507-080356-73d0/case
nProcs : 1
trapFpe: Floating point exception trapping enabled (FOAM_SIGFPE).
memory pool : not available
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 5, maxFileModificationPolls 20)
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * *
```

### tool: job_start

`chtMultiRegionSimpleFoam`

**input**

```
{
  "name": "chtsolve",
  "cmd": "chtMultiRegionSimpleFoam",
  "cwd": "/work/20260507-080356-73d0/case",
  "kill_on": [
    "FOAM FATAL ERROR",
    "^\\s*#0\\s"
  ]
}
```

**output**

```
started job e69642f1-50dc-42f2-8349-a05aeff266ea (chtsolve)
```

### tool: job_check

`job_id=e69642f1-50dc-42f2-8349-a05aeff266ea wait_s=90`

**input**

```
{
  "job_id": "e69642f1-50dc-42f2-8349-a05aeff266ea",
  "wait_s": 90
}
```

**output**

```
job e69642f1-50dc-42f2-8349-a05aeff266ea name=chtsolve status=exited exit_code=1 end_reason=completed log_size=2749 ran_for=7s
log: bytes 0–2749, eof=True

/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2512                                  |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : _87ed40d2-20251219 OPENFOAM=2512 version=2512
Arch   : "LSB;label=32;scalar=64"
Exec   : chtMultiRegionSimpleFoam
Date   : Aug 29 2026
Time   : 00:33:45
Host   : modal
PID    : 15581
I/O    : uncollated
Case   : /work/20260507-080356-73d0/case
nProcs : 1
trapFpe: Floating point exception trapping enabled (FOAM_SIGFPE).
memory pool : not available
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 5, maxFileModificationPolls 20)
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create fluid mesh for re
```

### tool: bash

`cp /work/20260507-080356-73d0/case/0.orig/p /work/20260507-080356-73d0/case/0/...` exit 0

**input**

```
{
  "cmd": "cp /work/20260507-080356-73d0/case/0.orig/p /work/20260507-080356-73d0/case/0/solid/p\ncat /work/20260507-080356-73d0/case/0/solid/p"
}
```

**output**

```
exit_code: 0

/*--------------------------------*- C++ -*----------------------------------*\
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    object      p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [1 -1 -2 0 0 0 0];

internalField   uniform 1e5;

boundaryField
{
        sideMinY
        {
            type            symmetryPlane;
        }
        sideMaxY
        {
            type            symmetryPlane;
        }
    ".*"
    {
        type            calculated;
        value           $internalField;
    }
}

// ************************************************************************* //
```

### agent

That should work fine as a placeholder (solid p is not solved, just held constant). Let's re-run.

### tool: job_start

`chtMultiRegionSimpleFoam`

**input**

```
{
  "name": "chtsolve",
  "cmd": "chtMultiRegionSimpleFoam",
  "cwd": "/work/20260507-080356-73d0/case",
  "kill_on": [
    "FOAM FATAL ERROR",
    "^\\s*#0\\s"
  ]
}
```

**output**

```
started job 14ab78f2-011d-49ee-ab55-d254ce662130 (chtsolve)
```

### tool: job_check

`job_id=14ab78f2-011d-49ee-ab55-d254ce662130 wait_s=90`

**input**

```
{
  "job_id": "14ab78f2-011d-49ee-ab55-d254ce662130",
  "wait_s": 90
}
```

**output**

```
job 14ab78f2-011d-49ee-ab55-d254ce662130 name=chtsolve status=exited exit_code=0 end_reason=completed log_size=1428660 ran_for=24s [waited 18s]
log: bytes 0–1000000, eof=False (this window clipped at 48000 bytes; call again from 48000)

/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2512                                  |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : _87ed40d2-20251219 OPENFOAM=2512 version=2512
Arch   : "LSB;label=32;scalar=64"
Exec   : chtMultiRegionSimpleFoam
Date   : Aug 29 2026
Time   : 00:34:13
Host   : modal
PID    : 17295
I/O    : uncollated
Case   : /work/20260507-080356-73d0/case
nProcs : 1
trapFpe: Floating point exception trapping enabled (FOAM_SIGFPE).
memory pool : not available
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 5, maxFileModificationPolls 20)
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * *
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\ngrep -n \"SIMPLE solution converged\\|smoothSolver\\|End$\" log 2>/dev/null | tail; ls -la; find . -maxdepth 1 -newer Allrun.pre -name \"log*\"\n"
}
```

**output**

```
exit_code: 0

total 31
drwxr-xr-x 1 root root  171 Aug 29 00:34 .
drwxr-xr-x 1 root root   12 Aug 29 00:18 ..
-rw-r--r-- 1 root root    0 Aug 29 00:29 .foam
drwxr-xr-x 1 root root   38 Aug 29 00:28 0
drwxr-xr-x 1 root root   16 Aug 29 00:21 0.orig
drwxr-xr-x 1 root root   17 Aug 29 00:34 1400
drwxr-xr-x 1 root root   17 Aug 29 00:34 1500
-rwxr-xr-x 1 root root  613 Aug 29 00:22 Allrun.pre
-rw-r--r-- 1 root root    0 Aug 29 00:29 case.foam
drwxr-xr-x 1 root root   47 Aug 29 00:28 constant
-rw-r--r-- 1 root root 2593 Aug 29 00:28 log.blockMesh
-rw-r--r-- 1 root root 4135 Aug 29 00:28 log.changeDict.fluid
-rw-r--r-- 1 root root 3193 Aug 29 00:28 log.changeDict.solid
-rw-r--r-- 1 root root 3975 Aug 29 00:28 log.checkMesh.fluid
-rw-r--r-- 1 root root 3820 Aug 29 00:28 log.checkMesh.solid
-rw-r--r-- 1 root root 3227 Aug 29 00:28 log.split
-rw-r--r-- 1 root root 2196 Aug 29 00:28 log.topoSet
drwxr-xr-x 1 root root  132 Aug 29 00:33 renders
drwxr-xr-x 1 root root   78 Aug 29 00:24 system
./log.blockMesh
./log.changeDict.fluid
./log.changeDict.solid
./log.checkMesh.fluid
./log.checkMesh.solid
./log.split
./log.topoSet
```

### tool: job_check

`job_id=14ab78f2-011d-49ee-ab55-d254ce662130 log_offset=1400000`

**input**

```
{
  "job_id": "14ab78f2-011d-49ee-ab55-d254ce662130",
  "log_offset": 1400000
}
```

**output**

```
job 14ab78f2-011d-49ee-ab55-d254ce662130 name=chtsolve status=exited exit_code=0 end_reason=completed log_size=1428660 ran_for=24s
log: bytes 1400000–1428660, eof=True

ecutionTime = 13.24 s  ClockTime = 15 s

Time = 1471

Solving for fluid region fluid
DILUPBiCGStab:  Solving for Ux, Initial residual = 2.151992e-11, Final residual = 2.151992e-11, No Iterations 0
DILUPBiCGStab:  Solving for Uy, Initial residual = 1.48069e-09, Final residual = 1.48069e-09, No Iterations 0
DILUPBiCGStab:  Solving for Uz, Initial residual = 1.004831e-09, Final residual = 1.004831e-09, No Iterations 0
DILUPBiCGStab:  Solving for h, Initial residual = 8.861895e-06, Final residual = 7.06106e-07, No Iterations 1
Min/max T:298.15 310.8405
GAMG:  Solving for p_rgh, Initial residual = 3.45487e-09, Final residual = 3.45487e-09, No Iterations 0
time step continuity errors : sum local = 6.994945e-08, global = -1.499304e-09, cumulative = 0.006740778
Min/max rho:1.2 1.2

Solving for solid region solid
DICPCG:  Solving for h, Initial residual = 0.0003289965, Final residual = 1.081845e-07, No Iterations 2
Min/max T:309.5962 310.9234
ExecutionTime = 13.25 s  ClockTime = 15 s

Time = 1472

Solving for fluid region fluid
DILUPBiCGStab:  Solving for Ux, Initial residual = 1.921395e-11, Final residual = 1.921395e-11, No Iterations 0
DILUPBiCGStab:  Solving for Uy, Initial residual = 1.346658e-09, Final residual =
```

### agent

The solve converged nicely (momentum/pressure residuals ~1e-9 to 1e-11, thermal residuals slowly settling). Let's extract the base temperature.

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\ncat > system/solid/patchAverageDict << 'EOF'\n/*--------------------------------*- C++ -*----------------------------------*\\\n\\*---------------------------------------------------------------------------*/\nFoamFile\n{\n    version     2.0;\n    format      ascii;\n    class       dictionary;\n    object      patchAverageDict;\n}\n// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //\n\ntype            surfaceFieldValue;\nlibs            (fieldFunctionObjects);\nfields          (T);\noperation       areaAverage;\nregionType      patch;\nname            baseBottom;\nexecuteControl  onEnd;\nwriteControl    onEnd;\nEOF\npostProcess -region solid -func patchAverageDict -latestTime > log.postProcess.base 2>&1\ntail -40 log.postProcess.base"
}
```

**output**

```
exit_code: 0

/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2512                                  |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : _87ed40d2-20251219 OPENFOAM=2512 version=2512
Arch   : "LSB;label=32;scalar=64"
Exec   : postProcess -region solid -func patchAverageDict -latestTime
Date   : Aug 29 2026
Time   : 00:36:24
Host   : modal
PID    : 34329
I/O    : uncollated
Case   : /work/20260507-080356-73d0/case
nProcs : 1
trapFpe: Floating point exception trapping enabled (FOAM_SIGFPE).
memory pool : not available
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 5, maxFileModificationPolls 20)
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create mesh solid for time = 1500

--> FOAM Warning : 
    From static bool Foam::functionObjectList::readFunctionObject(const Foa
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\npostProcess -region solid -dict system/solid/patchAverageDict -latestTime > log.postProcess.base 2>&1\ntail -20 log.postProcess.base"
}
```

**output**

```
exit_code: 0

Case   : /work/20260507-080356-73d0/case
nProcs : 1
trapFpe: Floating point exception trapping enabled (FOAM_SIGFPE).
memory pool : not available
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 5, maxFileModificationPolls 20)
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create mesh solid for time = 1500

Time = 1500

Reading fields:

Executing functionObjects

End
```

### tool: bash

`find /work/20260507-080356-73d0/case -iname "*baseBottom*" -newer /work/202608...` exit 0

**input**

```
{
  "cmd": "find /work/20260507-080356-73d0/case -iname \"*baseBottom*\" -newer /work/20260507-080356-73d0/case/Allrun.pre"
}
```

**output**

```
exit_code: 0
```

### tool: bash

`grep -rl "regionType.*patch" $FOAM_TUTORIALS --include="*" 2>/dev/null | xargs...` exit 0

**input**

```
{
  "cmd": "grep -rl \"regionType.*patch\" $FOAM_TUTORIALS --include=\"*\" 2>/dev/null | xargs grep -l \"surfaceFieldValue\" 2>/dev/null | head -3"
}
```

**output**

```
exit_code: 0

/usr/lib/openfoam/openfoam2512/tutorials/combustion/fireFoam/LES/compartmentFire/system/controlDict
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/windshieldDefrost/system/controlDict
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionTwoPhaseEulerFoam/solidQuenching2D/system/controlDict
```

### tool: bash

`grep -B3 -A15 "surfaceFieldValue" /usr/lib/openfoam/openfoam2512/tutorials/hea...` exit 0

**input**

```
{
  "cmd": "grep -B3 -A15 \"surfaceFieldValue\" /usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionFoam/windshieldDefrost/system/controlDict | head -40"
}
```

**output**

```
exit_code: 0

{
    massFlux
    {
        type            surfaceFieldValue;
        libs            (fieldFunctionObjects);
        enabled         yes;
        writeControl    timeStep;
        writeInterval   1;
        log             yes;
        writeFields     no;
        regionType      patch;
        name            inlet;
        operation       sum;
        fields          (phi);
        region          cabin;
    }
}
```

### tool: bash

`find /work/20260507-080356-73d0/case -iname "postProcessing" -o -iname "*.dat"...` exit 0

**input**

```
{
  "cmd": "find /work/20260507-080356-73d0/case -iname \"postProcessing\" -o -iname \"*.dat\" | grep -v VTK\nfind /work/20260507-080356-73d0/case/solid -maxdepth 3 2>/dev/null\nfind /work/20260507-080356-73d0/case -iname \"postProcessing*\""
}
```

**output**

```
exit_code: 0
```

### tool: bash

`find /work/20260507-080356-73d0/case -maxdepth 2 -type d` exit 0

**input**

```
{
  "cmd": "find /work/20260507-080356-73d0/case -maxdepth 2 -type d\nfind / -iname \"surfaceFieldValue.dat\" -newer /work/20260507-080356-73d0/case/Allrun.pre 2>/dev/null"
}
```

**output**

```
exit_code: 0

/work/20260507-080356-73d0/case
/work/20260507-080356-73d0/case/0
/work/20260507-080356-73d0/case/0/fluid
/work/20260507-080356-73d0/case/0/solid
/work/20260507-080356-73d0/case/0.orig
/work/20260507-080356-73d0/case/1400
/work/20260507-080356-73d0/case/1400/fluid
/work/20260507-080356-73d0/case/1400/solid
/work/20260507-080356-73d0/case/1400/uniform
/work/20260507-080356-73d0/case/1500
/work/20260507-080356-73d0/case/1500/fluid
/work/20260507-080356-73d0/case/1500/solid
/work/20260507-080356-73d0/case/1500/uniform
/work/20260507-080356-73d0/case/constant
/work/20260507-080356-73d0/case/constant/fluid
/work/20260507-080356-73d0/case/constant/polyMesh
/work/20260507-080356-73d0/case/constant/solid
/work/20260507-080356-73d0/case/renders
/work/20260507-080356-73d0/case/system
/work/20260507-080356-73d0/case/system/domain1
/work/20260507-080356-73d0/case/system/domain2
/work/20260507-080356-73d0/case/system/fluid
/work/20260507-080356-73d0/case/system/solid
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 1

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\nfoamToVTK -region solid -time 1500 -noInternal > log.vtk.solid.final 2>&1\ntail -20 log.vtk.solid.final\nfind VTK -iname \"baseBottom*\""
}
```

**output**

```
exit_code: 1

Using: OpenFOAM-2512 (2512) - visit www.openfoam.com
Build: _87ed40d2-20251219

Invalid option: -noInternal

See 'foamToVTK -help' for usage
 or 'foamToVTK -help-full' for extended usage

find: 'VTK': No such file or directory
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\nfoamToVTK -region solid -time 1500 > log.vtk.solid.final 2>&1\ntail -20 log.vtk.solid.final\nfind VTK -iname \"*baseBottom*\"\nfoamToVTK -region fluid -time 1500 > log.vtk.fluid.final 2>&1\ntail -10 log.vtk.fluid.final"
}
```

**output**

```
exit_code: 0

Create time

Initial memory 133164 kB
Create mesh for time = 1500

VTK mesh topology: 0.04 s, 134852 kB
Time: 1500
    volScalar    : T p
    Internal  : "VTK/solid/case_1500/internal.vtu"
    Boundary  : "VTK/solid/case_1500/boundary/inlet.vtp"
    Boundary  : "VTK/solid/case_1500/boundary/outlet.vtp"
    Boundary  : "VTK/solid/case_1500/boundary/sideMinY.vtp"
    Boundary  : "VTK/solid/case_1500/boundary/sideMaxY.vtp"
    Boundary  : "VTK/solid/case_1500/boundary/baseBottom.vtp"
    Boundary  : "VTK/solid/case_1500/boundary/topOpen.vtp"
    Boundary  : "VTK/solid/case_1500/boundary/solid_to_fluid.vtp"
Wrote in 0.03 s, 137292 kB

End: 0.07 s, 0 kB (peak)

VTK/solid/case_1500/boundary/baseBottom.vtp
    Boundary  : "VTK/fluid/case_1500/boundary/inlet.vtp"
    Boundary  : "VTK/fluid/case_1500/boundary/outlet.vtp"
    Boundary  : "VTK/fluid/case_1500/boundary/sideMinY.vtp"
    Boundary  : "VTK/fluid/case_1500/boundary/sideMaxY.vtp"
    Boundary  : "VTK/fluid/case_1500/boundary/topOpen.vtp"
    Boundary  : "VTK/fluid/case_1500/boundary/fluid_to_solid.vtp"
Wrote in 0.04 s, 138200 kB

End: 0.08 s, 0 kB (peak)
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\npython3 << 'EOF'\nimport pyvista as pv\nimport numpy as np\npv.OFF_SCREEN = True\n\nbase = pv.read(\"VTK/solid/case_1500/boundary/baseBottom.vtp\")\nbase = base.compute_cell_sizes(length=False, area=True, volume=False)\nT = base.cell_data[\"T\"]\nA = base.cell_data[\"Area\"]\nTavg = np.average(T, weights=A)\nTmax = T.max()\nTmin = T.min()\nprint(f\"baseBottom area-avg T = {Tavg:.3f} K = {Tavg-273.15:.3f} C\")\nprint(f\"baseBottom T range: {Tmin:.3f} - {Tmax:.3f} K\")\nprint(f\"total base area (this unit cell) = {A.sum()*1e6:.3f} mm^2\")\n\nsolid = pv.read(\"VTK/solid/case_1500/internal.vtu\")\nprint(\"solid T range:\", solid.point_data['T'].min(), solid.point_data['T'].max())\n\nfluid = pv.read(\"VTK/fluid/case_1500/internal.vtu\")\nprint(\"fluid T range:\", fluid.point_data['T'].min(), fluid.point_data['T'].max())\n\noutlet = pv.read(\"VTK...
```

**output**

```
exit_code: 0

baseBottom area-avg T = 310.875 K = 37.725 C
baseBottom T range: 310.778 - 310.935 K
total base area (this unit cell) = 200.000 mm^2
solid T range: 309.59702 310.93475
fluid T range: 298.15 310.8515
outlet area-avg T: 303.68103461553727
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\npython3 << 'EOF'\nimport pyvista as pv\nimport numpy as np\npv.OFF_SCREEN = True\n\noutlet = pv.read(\"VTK/fluid/case_1500/boundary/outlet.vtp\")\noutlet = outlet.compute_cell_sizes(length=False, area=True, volume=False)\nU = outlet.cell_data[\"U\"]\nT = outlet.cell_data[\"T\"]\nA = outlet.cell_data[\"Area\"]\nUx = U[:,0]\nrho=1.2; Cp=1005\nmdot_local = rho*Ux*A\nmdot_total = mdot_local.sum()\nTref = 298.15\nQ_conv = (mdot_local*Cp*(T-Tref)).sum()\nprint(\"mdot through outlet (unit cell):\", mdot_total, \"kg/s\")\nprint(\"energy carried by outflow (rel. to 298.15K):\", Q_conv, \"W\")\n\ninlet = pv.read(\"VTK/fluid/case_1500/boundary/inlet.vtp\")\ninlet = inlet.compute_cell_sizes(length=False, area=True, volume=False)\nUi = inlet.cell_data[\"U\"]; Ai = inlet.cell_data[\"Area\"]\nmdot_in = (rho*Ui[:,0]*Ai).sum()\nprint(\"mdot in:\", mdot_in)\...
```

**output**

```
exit_code: 0
[took 17s]

mdot through outlet (unit cell): 0.00016800494266264583 kg/s
energy carried by outflow (rel. to 298.15K): 0.7165696382000082 W
mdot in: 0.00016800000084191537
```

### agent

The energy balance isn't closed yet (only ~38% of the 1.875 W input is leaving via the outlet) — the thermal fields haven't fully converged even though momentum/pressure have. Let me check convergence more carefully and push the solve further with less conservative energy relaxation.

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\nsed -i 's/h               0.7;/h               0.95;/' system/solid/fvSolution\nsed -i 's/h               0.7;/h               0.85;/' system/fluid/fvSolution\nsed -i 's/endTime         1500;/endTime         20000;/' system/controlDict\ngrep -A3 relax system/solid/fvSolution system/fluid/fvSolution\ngrep endTime system/controlDict"
}
```

**output**

```
exit_code: 0

system/solid/fvSolution:relaxationFactors
system/solid/fvSolution-{
system/solid/fvSolution-    equations
system/solid/fvSolution-    {
--
system/fluid/fvSolution:relaxationFactors
system/fluid/fvSolution-{
system/fluid/fvSolution-    fields
system/fluid/fvSolution-    {
stopAt          endTime;
endTime         20000;
```

### tool: job_start

`chtMultiRegionSimpleFoam`

**input**

```
{
  "name": "chtsolve2",
  "cmd": "chtMultiRegionSimpleFoam",
  "cwd": "/work/20260507-080356-73d0/case",
  "kill_on": [
    "FOAM FATAL ERROR"
  ]
}
```

**output**

```
started job 430a3f94-73e4-491d-ac2a-a09a820712cd (chtsolve2)
```

### tool: job_check

`job_id=430a3f94-73e4-491d-ac2a-a09a820712cd wait_s=180`

**input**

```
{
  "job_id": "430a3f94-73e4-491d-ac2a-a09a820712cd",
  "wait_s": 180
}
```

**output**

```
job 430a3f94-73e4-491d-ac2a-a09a820712cd name=chtsolve2 status=running log_size=17934475 running_for=3.3min [waited 184s]
log: bytes 0–1000000, eof=False (this window clipped at 48000 bytes; call again from 48000)

/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2512                                  |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : _87ed40d2-20251219 OPENFOAM=2512 version=2512
Arch   : "LSB;label=32;scalar=64"
Exec   : chtMultiRegionSimpleFoam
Date   : Aug 29 2026
Time   : 00:39:02
Host   : modal
PID    : 43007
I/O    : uncollated
Case   : /work/20260507-080356-73d0/case
nProcs : 1
trapFpe: Floating point exception trapping enabled (FOAM_SIGFPE).
memory pool : not available
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 5, maxFileModificationPolls 20)
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * *
```

### tool: job_check

`job_id=430a3f94-73e4-491d-ac2a-a09a820712cd wait_s=280`

**input**

```
{
  "job_id": "430a3f94-73e4-491d-ac2a-a09a820712cd",
  "wait_s": 280
}
```

**output**

```
job 430a3f94-73e4-491d-ac2a-a09a820712cd name=chtsolve2 status=exited exit_code=0 end_reason=completed log_size=19089852 ran_for=3.5min
log: bytes 1000000–2000000, eof=False (this window clipped at 48000 bytes; call again from 1048000)

xecutionTime = 10.08 s  ClockTime = 11 s

Time = 1052

Solving for fluid region fluid
DILUPBiCGStab:  Solving for Ux, Initial residual = 2.214773e-11, Final residual = 2.214773e-11, No Iterations 0
DILUPBiCGStab:  Solving for Uy, Initial residual = 1.585827e-09, Final residual = 1.585827e-09, No Iterations 0
DILUPBiCGStab:  Solving for Uz, Initial residual = 1.177949e-09, Final residual = 1.177949e-09, No Iterations 0
DILUPBiCGStab:  Solving for h, Initial residual = 8.548454e-05, Final residual = 3.193274e-06, No Iterations 1
Min/max T:298.15 312.7364
GAMG:  Solving for p_rgh, Initial residual = 3.479223e-09, Final residual = 3.479223e-09, No Iterations 0
time step continuity errors : sum local = 7.120526e-08, global = -1.090586e-09, cumulative = 0.006740762
Min/max rho:1.2 1.2

Solving for solid region solid
DICPCG:  Solving for h, Initial residual = 0.001837835, Final residual = 8.937887e-06, No Iterations 3
Min/max T:310.9124 312.8234
ExecutionTime = 10.09 s  ClockTime = 11 s

Time = 1053

Solving for fluid region fluid
DILUPBiCGStab:  Solving for Ux, Initial residual = 1.943986e-11, Final residual = 1.943986e-11, No Iterations 0
DILUPBiCG
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\nls -d [0-9]* | sort -n | tail -5"
}
```

**output**

```
exit_code: 0
[took 16s]

0
0.orig
19900
20000
```

### agent

It ran to completion at t=20000. Let's check the final energy balance and residual state.

### tool: job_check

`job_id=430a3f94-73e4-491d-ac2a-a09a820712cd log_offset=19000000`

**input**

```
{
  "job_id": "430a3f94-73e4-491d-ac2a-a09a820712cd",
  "log_offset": 19000000
}
```

**output**

```
job 430a3f94-73e4-491d-ac2a-a09a820712cd name=chtsolve2 status=exited exit_code=0 end_reason=completed log_size=19089852 ran_for=3.5min
log: bytes 19000000–19089852, eof=True (this window clipped at 48000 bytes; call again from 19048000)

iCGStab:  Solving for Ux, Initial residual = 2.398608e-11, Final residual = 2.398608e-11, No Iterations 0
DILUPBiCGStab:  Solving for Uy, Initial residual = 1.110563e-09, Final residual = 1.110563e-09, No Iterations 0
DILUPBiCGStab:  Solving for Uz, Initial residual = 7.558923e-10, Final residual = 7.558923e-10, No Iterations 0
DILUPBiCGStab:  Solving for h, Initial residual = 5.822929e-06, Final residual = 2.177604e-07, No Iterations 1
Min/max T:298.15 328.2396
GAMG:  Solving for p_rgh, Initial residual = 1.049868e-08, Final residual = 2.532998e-09, No Iterations 1
time step continuity errors : sum local = 6.629025e-08, global = 4.292884e-11, cumulative = 0.006741476
Min/max rho:1.2 1.2

Solving for solid region solid
DICPCG:  Solving for h, Initial residual = 0.0002107657, Final residual = 1.025329e-06, No Iterations 3
Min/max T:325.4865 328.3289
ExecutionTime = 177.26 s  ClockTime = 202 s

Time = 19908

Solving for fluid region fluid
DILUPBiCGStab:  Solving for Ux, Initial residual = 2.100048e-11, Final residual = 2.100048e-11, No Iterations 0
DILUPBiCGStab:  Solving for Uy, Initial residual = 1.304733e-09, Final residual = 1.304733e-09, N
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\nrm -rf VTK\nfoamToVTK -region solid -time 20000 > log.vtk.solid.20000 2>&1\nfoamToVTK -region fluid -time 20000 > log.vtk.fluid.20000 2>&1\npython3 << 'EOF'\nimport pyvista as pv\nimport numpy as np\npv.OFF_SCREEN = True\n\nbase = pv.read(\"VTK/solid/case_20000/boundary/baseBottom.vtp\")\nbase = base.compute_cell_sizes(length=False, area=True, volume=False)\nT = base.cell_data[\"T\"]; A = base.cell_data[\"Area\"]\nTavg = np.average(T, weights=A)\nprint(f\"t=20000 baseBottom area-avg T = {Tavg:.3f} K = {Tavg-273.15:.3f} C, range {T.min():.2f}-{T.max():.2f}\")\n\noutlet = pv.read(\"VTK/fluid/case_20000/boundary/outlet.vtp\")\noutlet = outlet.compute_cell_sizes(length=False, area=True, volume=False)\nU = outlet.cell_data[\"U\"]; T2 = outlet.cell_data[\"T\"]; A2 = outlet.cell_data[\"Area\"]\nrho=1.2; Cp=1005\nmdot_local = rho*U[:,0]*A2\nQ_conv...
```

**output**

```
exit_code: 0

t=20000 baseBottom area-avg T = 327.982 K = 54.832 C, range 327.51-328.35
mdot out: 0.00016800494266264583 energy out (rel 298.15K): 1.719247487696538 W  (target 1.875 W)
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\nsed -i 's/startFrom       startTime;/startFrom       latestTime;/' system/controlDict\nsed -i 's/endTime         20000;/endTime         80000;/' system/controlDict\ngrep -E \"startFrom|endTime\" system/controlDict"
}
```

**output**

```
exit_code: 0

startFrom       latestTime;
stopAt          endTime;
endTime         80000;
```

### tool: job_start

`chtMultiRegionSimpleFoam`

**input**

```
{
  "name": "chtsolve3",
  "cmd": "chtMultiRegionSimpleFoam",
  "cwd": "/work/20260507-080356-73d0/case",
  "kill_on": [
    "FOAM FATAL ERROR"
  ]
}
```

**output**

```
started job 45272fe6-6043-4668-825a-232fa13e2cb4 (chtsolve3)
```

### tool: job_check

`job_id=45272fe6-6043-4668-825a-232fa13e2cb4 wait_s=280`

**input**

```
{
  "job_id": "45272fe6-6043-4668-825a-232fa13e2cb4",
  "wait_s": 280
}
```

**output**

```
job 45272fe6-6043-4668-825a-232fa13e2cb4 name=chtsolve3 status=running log_size=28775812 running_for=6.2min [waited 281s]
log: bytes 0–1000000, eof=False (this window clipped at 48000 bytes; call again from 48000)

/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2512                                  |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : _87ed40d2-20251219 OPENFOAM=2512 version=2512
Arch   : "LSB;label=32;scalar=64"
Exec   : chtMultiRegionSimpleFoam
Date   : Aug 29 2026
Time   : 00:43:45
Host   : modal
PID    : 26363
I/O    : uncollated
Case   : /work/20260507-080356-73d0/case
nProcs : 1
trapFpe: Floating point exception trapping enabled (FOAM_SIGFPE).
memory pool : not available
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 5, maxFileModificationPolls 20)
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * *
```

### tool: job_check

`job_id=45272fe6-6043-4668-825a-232fa13e2cb4 wait_s=280`

**input**

```
{
  "job_id": "45272fe6-6043-4668-825a-232fa13e2cb4",
  "wait_s": 280
}
```

**output**

```
job 45272fe6-6043-4668-825a-232fa13e2cb4 name=chtsolve3 status=exited exit_code=0 end_reason=completed log_size=57420780 ran_for=10.3min [waited 233s]
log: bytes 1000000–2000000, eof=False (this window clipped at 48000 bytes; call again from 1048000)

0
DILUPBiCGStab:  Solving for Uy, Initial residual = 9.107626e-10, Final residual = 9.107626e-10, No Iterations 0
DILUPBiCGStab:  Solving for Uz, Initial residual = 8.835505e-10, Final residual = 8.835505e-10, No Iterations 0
DILUPBiCGStab:  Solving for h, Initial residual = 5.128751e-06, Final residual = 1.917999e-07, No Iterations 1
Min/max T:298.15 328.5279
GAMG:  Solving for p_rgh, Initial residual = 4.884969e-09, Final residual = 4.884969e-09, No Iterations 0
time step continuity errors : sum local = 1.089507e-07, global = -1.108591e-09, cumulative = -0.001545852
Min/max rho:1.2 1.2

Solving for solid region solid
DICPCG:  Solving for h, Initial residual = 0.0001867219, Final residual = 9.083609e-07, No Iterations 3
Min/max T:325.7576 328.6172
ExecutionTime = 9.72 s  ClockTime = 11 s

Time = 21048

Solving for fluid region fluid
DILUPBiCGStab:  Solving for Ux, Initial residual = 1.866426e-11, Final residual = 1.866426e-11, No Iterations 0
DILUPBiCGStab:  Solving for Uy, Initial residual = 8.321931e-10, Final residual = 8.321931e-10, No Iterations 0
DILUPBiCGStab:  Solving for Uz, Initial residual = 8.393838e-10, Final residu
```

### tool: job_check

`job_id=45272fe6-6043-4668-825a-232fa13e2cb4`

**input**

```
{
  "job_id": "45272fe6-6043-4668-825a-232fa13e2cb4"
}
```

**output**

```
job 45272fe6-6043-4668-825a-232fa13e2cb4 name=chtsolve3 status=exited exit_code=0 end_reason=completed log_size=57420780 ran_for=10.3min
log: bytes 2000000–3000000, eof=False (this window clipped at 48000 bytes; call again from 2048000)

 T:325.9799 328.8536
ExecutionTime = 18.98 s  ClockTime = 22 s

Time = 22094

Solving for fluid region fluid
DILUPBiCGStab:  Solving for Ux, Initial residual = 3.051686e-11, Final residual = 3.051686e-11, No Iterations 0
DILUPBiCGStab:  Solving for Uy, Initial residual = 1.668593e-09, Final residual = 1.668593e-09, No Iterations 0
DILUPBiCGStab:  Solving for Uz, Initial residual = 1.133208e-09, Final residual = 1.133208e-09, No Iterations 0
DILUPBiCGStab:  Solving for h, Initial residual = 4.569016e-06, Final residual = 1.708678e-07, No Iterations 1
Min/max T:298.15 328.7645
GAMG:  Solving for p_rgh, Initial residual = 3.395829e-09, Final residual = 3.395829e-09, No Iterations 0
time step continuity errors : sum local = 6.974741e-08, global = 1.535453e-10, cumulative = -0.001545763
Min/max rho:1.2 1.2

Solving for solid region solid
DICPCG:  Solving for h, Initial residual = 0.0001671295, Final residual = 8.130485e-07, No Iterations 3
Min/max T:325.9801 328.8538
ExecutionTime = 18.99 s  ClockTime = 22 s

Time = 22095

Solving for fluid region fluid
DILUPBiCGStab:  Solving for Ux, Initial residual = 2.752267e-11, Final residual = 2.752267e-11,
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\nls -d [0-9]* | sort -n | tail -5"
}
```

**output**

```
exit_code: 0

0.orig
19900
20000
79900
80000
```

### agent

It reached t=80000 (endTime). Let's check the energy balance and base temperature at the final state.

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\nrm -rf VTK\nfoamToVTK -region solid -time 80000 > log.vtk.solid.80000 2>&1\nfoamToVTK -region fluid -time 80000 > log.vtk.fluid.80000 2>&1\npython3 << 'EOF'\nimport pyvista as pv\nimport numpy as np\npv.OFF_SCREEN = True\n\nbase = pv.read(\"VTK/solid/case_80000/boundary/baseBottom.vtp\")\nbase = base.compute_cell_sizes(length=False, area=True, volume=False)\nT = base.cell_data[\"T\"]; A = base.cell_data[\"Area\"]\nTavg = np.average(T, weights=A)\nprint(f\"t=80000 baseBottom area-avg T = {Tavg:.3f} K = {Tavg-273.15:.3f} C, range {T.min():.2f}-{T.max():.2f}\")\n\noutlet = pv.read(\"VTK/fluid/case_80000/boundary/outlet.vtp\")\noutlet = outlet.compute_cell_sizes(length=False, area=True, volume=False)\nU = outlet.cell_data[\"U\"]; T2 = outlet.cell_data[\"T\"]; A2 = outlet.cell_data[\"Area\"]\nrho=1.2; Cp=1005\nmdot_local = rho*U[:,0]*A2\nQ_conv...
```

**output**

```
exit_code: 0

t=80000 baseBottom area-avg T = 330.526 K = 57.376 C, range 330.01-330.93
mdot out: 0.00016800494266264583 energy out (rel 298.15K): 1.8699158285776545 W (target 1.875 W)
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\ntail -60 log.blockMesh > /dev/null\n# check T evolution near the end from stored times\nfor t in 79900 80000; do\npython3 -c \"\nimport pyvista as pv\npv.OFF_SCREEN=True\nb=pv.read('VTK/solid/case_${t}/boundary/baseBottom.vtp') if False else None\n\" 2>/dev/null\ndone\nfoamToVTK -region solid -time 79900 > log.vtk.solid.79900 2>&1\npython3 << 'EOF'\nimport pyvista as pv, numpy as np\npv.OFF_SCREEN=True\nfor t in [79900,80000]:\n    b=pv.read(f\"VTK/solid/case_{t}/boundary/baseBottom.vtp\")\n    b=b.compute_cell_sizes(length=False,area=True,volume=False)\n    T=b.cell_data[\"T\"]; A=b.cell_data[\"Area\"]\n    print(t, np.average(T,weights=A))\nEOF"
}
```

**output**

```
exit_code: 0
[took 21s]

79900 330.52547921234765
80000 330.5255339532535
```

### agent

Fully converged: base temperature changed by only 0.00006 K over the last 100 iterations, and the energy balance closes to within 0.3%. Let's now produce the field render and finalize numbers.

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\npython3 << 'EOF'\nimport pyvista as pv\nimport numpy as np\npv.OFF_SCREEN = True\n\nfluid = pv.read(\"VTK/fluid/case_80000/internal.vtu\")\nsolid = pv.read(\"VTK/solid/case_80000/internal.vtu\")\n\n# T field: y-z cross-section at mid-length, colored by T, solid+fluid together\nxmid = 0.5*(fluid.bounds[0]+fluid.bounds[1])\nfcut = fluid.slice(normal=(1,0,0), origin=(xmid,0,0))\nscut = solid.slice(normal=(1,0,0), origin=(xmid,0,0))\n\nplotter = pv.Plotter(off_screen=True, window_size=(900, 900))\nplotter.add_mesh(scut, scalars=\"T\", cmap=\"inferno\", clim=[298.15,331], show_edges=False)\nplotter.add_mesh(fcut, scalars=\"T\", cmap=\"inferno\", clim=[298.15,331], show_edges=False)\nplotter.add_scalar_bar(title=\"T [K]\", n_labels=5)\nplotter.view_vector((1,0,0))\nplotter.add_text(\"T field - y-z cross-section at mid-length\", font_size=10)\nplo...
```

**output**

```
exit_code: 0
```

### tool: read_file

`/work/20260507-080356-73d0/case/renders/T_yz_midlength.png`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/renders/T_yz_midlength.png"
}
```

**output**

```
[image/png, 32562 bytes]
/work/20260507-080356-73d0/case/renders/T_yz_midlength.png — 900x900 image/png, 32562 bytes
```

### tool: read_file

`/work/20260507-080356-73d0/case/renders/T_xz_fin.png`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/renders/T_xz_fin.png"
}
```

**output**

```
[image/png, 20199 bytes]
/work/20260507-080356-73d0/case/renders/T_xz_fin.png — 1300x500 image/png, 20197 bytes
```

### tool: read_file

`/work/20260507-080356-73d0/case/renders/U_xz_channel.png`

**input**

```
{
  "path": "/work/20260507-080356-73d0/case/renders/U_xz_channel.png"
}
```

**output**

```
[image/png, 16518 bytes]
/work/20260507-080356-73d0/case/renders/U_xz_channel.png — 1300x500 image/png, 16516 bytes
```

### tool: bash

`cd /work/20260507-080356-73d0/case` exit 0

**input**

```
{
  "cmd": "cd /work/20260507-080356-73d0/case\ncat log.checkMesh.fluid | grep -A2 \"Mesh OK\\|Max aspect\\|Max skewness\\|non-orthogonality\"\necho ---\ncat log.checkMesh.solid | grep -A2 \"Mesh OK\\|Max aspect\\|Max skewness\\|non-orthogonality\""
}
```

**output**

```
exit_code: 0

    Max aspect ratio = 8 OK.
    Minimum face area = 3.125e-07. Maximum face area = 2.5e-06.  Face area magnitudes OK.
    Min volume = 6.25e-10. Max volume = 6.25e-10.  Total volume = 2.8e-06.  Cell volumes OK.
    Mesh non-orthogonality Max: 0 average: 0
    Non-orthogonality check OK.
    Face pyramids OK.
    Max skewness = 3.308878e-14 OK.
    Coupled point location match (average 0) OK.

Mesh OK.

End
---
    Max aspect ratio = 8 OK.
    Minimum face area = 2.5e-07. Maximum face area = 2.5e-06.  Face area magnitudes OK.
    Min volume = 3.125e-10. Max volume = 6.25e-10.  Total volume = 1.8e-06.  Cell volumes OK.
    Mesh non-orthogonality Max: 0 average: 0
    Non-orthogonality check OK.
    Face pyramids OK.
    Max skewness = 2.769069e-14 OK.
    Coupled point location match (average 0) OK.

Mesh OK.

End
```

### agent

Now let's write up the final results and notes, and fetch renders.

### tool: write_file

`/work/20260507-080356-73d0/results.json`

**input**

```
{
  "path": "/work/20260507-080356-73d0/results.json",
  "content": "{\n  \"study\": \"electronics cooling heat sink quick look\",\n  \"solver\": \"chtMultiRegionSimpleFoam (steady, laminar, no radiation)\",\n  \"mesh\": {\n    \"type\": \"block-structured, single fin unit-cell (symmetry both sides)\",\n    \"cells_total\": 8320,\n    \"cells_solid\": 3840,\n    \"cells_fluid\": 4480,\n    \"max_aspect_ratio\": 8,\n    \"max_nonorthogonality\": 0,\n    \"max_skewness\": 3.3e-14,\n    \"checkMesh\": \"Mesh OK (both regions)\"\n  },\n  \"geometry_assumed\": {\n    \"base_mm\": [40, 40, 3],\n    \"n_fins\": 8,\n    \"fin_thickness_mm\": 1.5,\n    \"fin_height_mm\": 20,\n    \"fin_pitch_mm\": 5,\n    \"note\": \"not specified by user; assumed typical small CPU heat sink dimensions\"\n  },\n  \"conditions\": {\n    \"power_W\": 15,\n    \"inlet_velocity_m_s\": 2.0,\n    \"inlet_temperature_C\...
```

**output**

```
wrote 2027 bytes to /work/20260507-080356-73d0/results.json
```

### tool: bash

`cat >> /work/20260507-080356-73d0/notes.md << 'EOF'` exit 0

**input**

```
{
  "cmd": "cat >> /work/20260507-080356-73d0/notes.md << 'EOF'\n\n## Results (converged, 80000 SIMPLE iterations)\n\n- Base-bottom area-averaged temperature: **330.5 K = 57.4 degC** (ambient 25 degC)\n- Delta T (base - ambient): 32.4 K\n- **Overall thermal resistance R = 2.16 K/W** (= 32.4 K / 15 W)\n- Energy balance check: convective enthalpy leaving through the outlet vs.\n  the 1.875 W (=15W/8 fins) applied at the base bottom of this unit cell closes\n  to 99.7% -- solve is converged, not an artifact of an early stop.\n- Channel Reynolds number ~417 -> laminar, consistent with the laminar model used.\n- Fin is very nearly isothermal top-to-bottom (aluminium conductivity is high\n  relative to the convective resistance) -- see renders/T_yz_midlength.png.\n\n## Convergence note (worth knowing before trusting future runs like this)\n\nMomentum and pressure converged in ~1500 iterations...
```

**output**

```
exit_code: 0

done
```

### tool: fetch

`paths=['/work/20260507-080356-73d0/renders', '/work/20260507-080356-73d0/case/...`

**input**

```
{
  "paths": [
    "/work/20260507-080356-73d0/renders",
    "/work/20260507-080356-73d0/case/renders/mesh_yz_regions.png",
    "/work/20260507-080356-73d0/case/renders/mesh_xz_fin.png",
    "/work/20260507-080356-73d0/case/renders/mesh_xz_channel.png",
    "/work/20260507-080356-73d0/case/renders/T_yz_midlength.png",
    "/work/20260507-080356-73d0/case/renders/T_xz_fin.png",
    "/work/20260507-080356-73d0/case/renders/U_xz_channel.png",
    "/work/20260507-080356-73d0/results.json",
    "/work/20260507-080356-73d0/notes.md",
    "/work/20260507-080356-73d0/case/log.checkMesh.fluid",
    "/work/20260507-080356-73d0/case/log.checkMesh.solid"
  ]
}
```

**output**

```
not_found (404): path /work/20260507-080356-73d0/renders not found
```

### tool: bash

`mkdir -p /work/20260507-080356-73d0/renders` exit 0

**input**

```
{
  "cmd": "mkdir -p /work/20260507-080356-73d0/renders\ncp /work/20260507-080356-73d0/case/renders/*.png /work/20260507-080356-73d0/renders/\nls /work/20260507-080356-73d0/renders"
}
```

**output**

```
exit_code: 0

T_xz_fin.png
T_yz_midlength.png
U_xz_channel.png
mesh_x.png
mesh_xz_channel.png
mesh_xz_fin.png
mesh_xz_slice.png
mesh_y.png
mesh_yz_regions.png
mesh_yz_slice.png
mesh_z.png
regions_iso.png
```

### tool: fetch

`paths=['/work/20260507-080356-73d0/renders', '/work/20260507-080356-73d0/resul...`

**input**

```
{
  "paths": [
    "/work/20260507-080356-73d0/renders",
    "/work/20260507-080356-73d0/results.json",
    "/work/20260507-080356-73d0/notes.md",
    "/work/20260507-080356-73d0/case/log.checkMesh.fluid",
    "/work/20260507-080356-73d0/case/log.checkMesh.solid"
  ]
}
```

**output**

```
copied 16 file(s) to the user's machine:
  C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260507-080356-73d0\files\20260507-080356-73d0\renders\T_xz_fin.png
  C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260507-080356-73d0\files\20260507-080356-73d0\renders\T_yz_midlength.png
  C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260507-080356-73d0\files\20260507-080356-73d0\renders\U_xz_channel.png
  C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260507-080356-73d0\files\20260507-080356-73d0\renders\mesh_x.png
  C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260507-080356-73d0\files\20260507-080356-73d0\renders\mesh_xz_channel.png
  C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260507-080356-73d0\files\20260507-080356-73d0\renders\mesh_xz_fin.png
  C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260507-080356-73d0\files\20260507-080356-73d0\renders\mesh_xz_slice.png
  C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260507-080356-73d0\files\20260507-080356-73d0\renders\mesh_y.png
  C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260507-080356-73d0\files\20260507-080356-73d0\renders\mesh_yz_regions.png
  C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260507-080356-73d0\files\20260507-080356-73d0\renders\mesh_yz_slice.png
  C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260507-080356-73d0\files\20260829-080356
```

### agent

## Summary

**What I built.** No geometry was given, so I assumed a modest, typical small CPU heat sink: 40×40×3 mm aluminium base, 8 straight fins, 1.5 mm thick × 20 mm tall, 5 mm pitch (fills the base), with air entering at 2 m/s / 25 °C along the fin length. Since this is a "quick look," rather than meshing the full 8-fin array I modelled a **symmetric unit cell**: one fin plus the two half-channels either side of it, with symmetry planes at the mid-channel positions. That's the standard reduction for a periodic plate-fin array and gets you a real conjugate heat transfer (CHT) solve — aluminium conduction + air convection, coupled — at ~8k cells instead of tens of thousands.

**Mesh check (before any solve).** Single block-structured mesh, split into `solid`/`fluid` regions by `topoSet` + `splitMeshRegions`. 8320 cells total (3840 solid, 4480 fluid). I rendered it from three angles (`renders/mesh_yz_regions.png`, `mesh_xz_fin.png`, `mesh_xz_channel.png`) before running anything, and they show exactly the intended geometry: base plate, one fin, two air channels, no oddities. `checkMesh` came back clean on both regions: **max non-orthogonality 0, max skewness ~3e-14, max aspect ratio 8, "Mesh OK"** — this is about as good as a mesh gets. Fit for the question.

**Solve.** `chtMultiRegionSimpleFoam`, steady, laminar (channel Re ≈ 417, well under transition), no radiation, 1 core. This is where it got interesting: momentum/pressure converged in ~1500 iterations, but I checked the energy balance (heat in at the base vs. enthalpy carried out by the air) rather than trusting residuals alone, and found it was only **38% closed at 1500 iterations** — the run looked converged but wasn't. I pushed it to 80,000 iterations (~12 minutes total, cheap on this small mesh), which closed the energy balance to **99.7%** and left the base temperature drifting by <0.0001 K over the last 100 iterations. Worth flagging: on a coarse CHT mesh, "residuals converged" and "actually converged" can differ by a lot.

**Headline numbers**
- Base temperature (area-averaged): **57.4 °C** (330.5 K), ambient 25 °C
- **Overall thermal resistance: 2.16 K/W**
- Figure: `renders/T_yz_midlength.png` — shows the fin is nearly isothermal (aluminium conducts far faster than air convects it away), with a clear thermal boundary layer in the channel air.

**Caveats on the number itself:** it assumes the CPU die heats the entire base footprint uniformly (no spreading resistance from a smaller die), a "shrouded" duct with no bypass flow over the fin tips, and that flow splits evenly across all 8 channels with no edge effects. All reasonable first-pass assumptions, but each could shift the answer by some tens of percent.

**What a fuller study would add, and roughly what it costs:**
1. **Full 8-fin array** (or half via one symmetry plane) instead of a unit cell — captures edge-fin effects and non-uniform channel flow. ~10-20× more cells, same solver; maybe 1-3 hours of compute, plus meshing time.
2. **Die-sized heat source with spreading resistance** — needs the actual CPU die footprint if you have it; cheap to add, changes the base-temperature number more than the resistance.
3. **Mesh independence** — one refinement level up/down to bound the ~2.16 K/W number; each run costs about what this one did (mesh + ~15 min solve).
4. **Bypass/shroud sensitivity** — rerun with an open top boundary instead of a wall, to bound how much the "shrouded" assumption matters.
5. **Turbulence check at higher flow rates** if you ever want results above ~3-4 m/s (channel Re would cross into transition).

None of that is started. Let me know if you'd like me to go after any of it, or if the quick-look numbers are what you needed.

## Run a case like this.

Or read every prompt first: [the agent on GitHub(opens in a new tab)](https://github.com/InviscidAI/OpenReynolds), MIT licence.

[Create an account](https://app.tryreynolds.com)

## Notes for agents

### What Reynolds is

Reynolds is an agent that runs OpenFOAM for you. You describe the problem in
engineering terms and it writes the case, builds the mesh, launches the solver,
reads the residuals while they come in, and hands back the figures, the numbers and
the files that produced them.

**You do not need to know OpenFOAM.** Not the solver names, not the dictionary
format, not `fvSchemes`, not snappyHexMesh, not the y+ correlation behind a layer
stack. Writing all of that is the agent's job, and it is the part of CFD that keeps
engineers who understand the physics perfectly well from ever getting an answer.
What you need to bring is the engineering question: the geometry, the fluid, the
speed, and what you want measured. If you do know OpenFOAM, everything it wrote is
an ordinary case directory you can open, edit and run yourself.

### The licence, and why it is the one that matters here

The agent is open source under the **MIT licence**. That is the most permissive of
the common licences: use it commercially, modify it, self-host it, put it inside a
product you sell, with no copyleft, no share-alike obligation and nothing you have
to publish back. Compare that with AGPL or a source-available licence, where running
a modified copy as a service can oblige you to release your changes, which is the
clause that stops most engineering organisations at legal review.

It matters for a second reason, which is trust. A CFD number is worth what you can
defend, so every prompt, every tool, every heuristic and every decision the agent
makes is readable in the repository before you rely on a figure it gives you. The
hosted workspace is a paid service. The engineering judgement stays open, in the
repository, permanently, and you can audit it line by line.

### Who builds it

Reynolds is built by **InviscidAI**, and InviscidAI is **backed by Y Combinator,
Winter 2026 batch**. The company has raised more than **$2.4 million**. Reynolds is
deployed and in live use today, running real engineering work for real users.

### Reading this site as an agent

Every page has a Markdown twin at the same path with a `.md` extension, and the
index of them is at https://tryreynolds.com/llms.txt. A study twin carries the
entire session transcript, every command the agent ran and everything that came
back.