---
title: "Static thrust from a drone propeller, and a boundary condition it had to reason about"
url: "https://tryreynolds.com/studies/propeller-static-thrust"
description: "Hover is the hardest condition to set up, because the standard far-field boundary condition divides by a freestream speed that is exactly zero. Reynolds hit the divide, diagnosed it, and replaced it with the right one."
---

**[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/propeller-static-thrust. It lives at https://tryreynolds.com/studies/propeller-static-thrust.md, and
[tryreynolds.com/llms.txt](https://tryreynolds.com/llms.txt) indexes every one of them.

# Static thrust from a drone propeller, and a boundary condition it had to reason about

Hover is the hardest condition to set up, because the standard far-field boundary condition divides by a freestream speed that is exactly zero. Reynolds hit the divide, diagnosed it, and replaced it with the right one.

RUN 05APPLIEDROTATING MACHINERYJULY 202620260716-234837-aa76

- **Asked**: An APC Slow Flyer 10×4.7 model propeller, two blades, 0.254 m diameter: static thrust and shaft power at 4,014 rpm.
- **Run**: simpleFoam with MRF · 38,270 cells · 4,014 rpm
- **Result**: T = 0.957 N, P = 10.4 W
- **Thrust**: T = 0.957 N at n = 66.9 rev/s
- **Shaft power**: P = 10.4 W from Q = 0.0248 N·m
- **Coefficients**: C_T = 0.042, C_P = 0.027, with n in rev/s so no stray 2π
- **Force steadiness**: Flat to 0.02% over the final 200 iterations

![Slipstream below a hovering two-bladed propeller](https://tryreynolds.com/assets/prop-flow-DI-Ah2vV.png)

Figure 1 Hover: air drawn in from the surroundings and accelerated into a contracting slipstream.

## Reading the geometry first

The propeller arrived as an STL. Before meshing anything, Reynolds inspected it: zero open edges, zero non-manifold edges, diameter measured at 0.254 m as stated, and the rotation axis identified as z. A propeller STL with a hole in it produces a mesh that snaps to nothing in particular and a thrust number that is pure fiction, so this is thirty seconds that saves an afternoon.

Rotation was handled with a Multiple Reference Frame: a cylindrical zone on the axis, radius 0.16 m or about 1.26 tip radii and 60 mm deep, inside which the equations pick up the rotating-frame source terms while the blade itself stays a perfectly ordinary stationary no-slip wall. That is the standard steady treatment for a rotor in a uniform condition, and it is dramatically cheaper than physically rotating a sliding mesh through thousands of timesteps. The MRF zone was built with topoSet to exactly the footprint of the mesh's own refinement region, so the frame change happens where the cells are already fine rather than across a jump in cell size.

## The boundary condition that cannot exist

Static thrust means hover: the propeller turns, and the air far away is still. That apparently simple condition breaks the boundary condition almost everyone reaches for first.

Reynolds started with the usual freestreamVelocity and freestreamPressure pair, and the run died with a floating-point exception. It then worked out why rather than trying different numbers: that boundary condition determines whether a face is an inlet or an outlet by normalising the freestream vector to get a flow direction, and normalising a vector of exactly zero length is a division by zero. The condition is not badly tuned for hover, it is undefined there.

The fix follows from the diagnosis. In hover, the propeller draws its own flow in from the surroundings, so the far field should be driven by pressure, not by a prescribed velocity: pressureInletOutletVelocity with totalPressure at zero, which lets air enter or leave each face according to what the rotor is doing to the pressure field. That is the physically correct treatment for a static test, and the run was stable on it.

## The numbers

At 4,014 rpm the run gives 0.957 N of thrust and 0.0248 N·m of shaft torque, which is 10.4 W of shaft power. Non-dimensionalised in the convention the propeller world actually uses, with rotation rate in revolutions per second rather than radians, that is C_T = 0.042 and C_P = 0.027.

The agent flagged the convention explicitly, and it is worth understanding why. Propeller coefficients are defined with n in rev/s, but solvers work in rad/s. Substituting one for the other leaves a factor of 2π in the thrust coefficient and 2π cubed in the power coefficient, and the result still looks like a plausible number. Stating which convention is in use is how a coefficient stays comparable with a manufacturer's data sheet.

![The two-bladed APC Slow Flyer propeller geometry as read from the supplied STL](https://tryreynolds.com/assets/prop-geometry-CHu4In-l.png)

Figure 2 The APC Slow Flyer 10×4.7 geometry, straight from the supplied STL.

![A cut through the mesh around the propeller blade](https://tryreynolds.com/assets/prop-mesh-BRU4QJpX.png)

Figure 3 Refinement bands around the blade surface and the rotating zone.

## 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.

22 messages, 80 tool calls

### you

/work/geometry/apc_sf_10x4.7_propeller.stl is an APC Slow Flyer 10x4.7 model propeller — two blades, 0.254 m diameter, in metres. I want the static thrust and the shaft power at 4014 rpm, and from those the thrust and power coefficients C_T = T/(rho n^2 D^4) and C_P = P/(rho n^3 D^5) with n in revolutions per second, so I can compare against the UIUC wind tunnel measurements. Note this is a rotating case, so tell me how you handled the rotation — a moving reference frame on a rotating fluid zone is the usual cheap way, and if you do that, be explicit about where you put the zone boundary. Careful with the coefficient definitions; n is rev/s not rad/s, and that is a factor of 2 pi to the wrong power if it slips. Quick look.

### tool: bash

`ls /work/.toolbox; echo ---; ls /work/.toolbox/notes; echo ---; cat /work/.too...` exit 0

**input**

```
{
  "cmd": "ls /work/.toolbox; echo ---; ls /work/.toolbox/notes; echo ---; cat /work/.toolbox/geometry_view.py 2>/dev/null | head -50; echo ---; ls /work/geometry; echo ---; nproc"
}
```

**output**

```
exit_code: 0

README.md
__pycache__
animate.py
case_gen.py
cells_estimate.py
first_look.py
gallery.py
geometry_view.py
log_digest.py
mesh_digest.py
notes
preflight.py
progress_report.py
render.py
results.py
study_run.py
study_state.py
---
bundle-layout.md
openfoam-agent-architecture.md
openfoam-field-notes.md
---
#!/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", "isomet
```

### tool: bash

`cd /work/geometry && python3 -c "` exit 0

**input**

```
{
  "cmd": "cd /work/geometry && python3 -c \"\nimport numpy as np\nimport pyvista as pv\nm = pv.read('apc_sf_10x4.7_propeller.stl')\nprint(m.bounds)\nprint(m.n_points, m.n_cells)\n\"\n"
}
```

**output**

```
exit_code: 0

BoundsTuple(x_min = -0.02159000001847744,
            x_max =  0.02159000001847744,
            y_min = -0.12701532244682312,
            y_max =  0.12701532244682312,
            z_min = -0.007123907562345266,
            z_max =  0.0044999998062849045)
47680 95348
```

### tool: bash

`mkdir -p /work/20260716-234837-aa76/renders` exit 0

**input**

```
{
  "cmd": "mkdir -p /work/20260716-234837-aa76/renders\ncd /work/20260716-234837-aa76\npython3 /work/.toolbox/geometry_view.py /work/geometry/apc_sf_10x4.7_propeller.stl --out renders/geom\n"
}
```

**output**

```
exit_code: 0

/work/geometry/apc_sf_10x4.7_propeller.stl
  faces 95,348   points 47,680   bodies 3
  bbox x [-0.02159, 0.02159]  y [-0.127015, 0.127015]  z [-0.00712391, 0.0045]
  extent 0.04318 x 0.254031 x 0.0116239  (OpenFOAM reads these as metres)
  open edges 0   non-manifold edges 0   duplicate points 0
  enclosed volume 1.8811e-05   surface area 0.0140388
  face area 2.38e-12 .. 1.52e-05   typical edge 0.000492   zero-area faces 0

renders/geom/geometry.png
```

### tool: bash

`cat /work/.toolbox/render.py | head -80` exit 0

**input**

```
{
  "cmd": "cat /work/.toolbox/render.py | head -80"
}
```

**output**

```
exit_code: 0

#!/usr/bin/env python3

"""A few fixed pyvista scenes: mesh cuts and field slices, saved as PNGs.

Headless via OSMesa. Fixed cameras so two runs of the same case are a visual diff

rather than two unrelated pictures.

    python3 render.py /work/case                      # latest time, all default scenes

    python3 render.py /work/case --fields U p --normal z --time 500

    python3 render.py /work/case --scene mesh --out /work/case/renders

"""

from __future__ import annotations

import argparse

from pathlib import Path

import numpy as np

import pyvista as pv

pv.OFF_SCREEN = True

NORMALS = {"x": (1, 0, 0), "y": (0, 1, 0), "z": (0, 0, 1)}

def open_case(case: Path, time: float | None):

    foam = case / f"{case.name}.foam"

    if not foam.exists():

        foam.write_text("")

    reader = pv.OpenFOAMReader(str(foam))

    times = list(reader.time_values)

    chosen = times[-1] if times else 0.0

    if time is not None and times:

        chosen = min(times, key=lambda t: abs(t - time))

    reader.set_active_time_value(chosen)

    reader.cell_to_point_creation = True

    return reader.read(), chosen, times

def internal_mesh(block):

    """The internalMesh block, whatever nesting this case produced."""

    if isinstance(block, pv.MultiBlock):

        if "internalMesh" in (block.keys() or []):

            return block["int
```

### agent

Geometry looks clean: closed surface (0 open/non-manifold edges), 3 bodies (2 blades + hub likely), diameter 0.254 m matches spec. Let me view it.

### tool: read_file

`/work/20260716-234837-aa76/renders/geom/geometry.png`

**input**

```
{
  "path": "/work/20260716-234837-aa76/renders/geom/geometry.png"
}
```

**output**

```
[image/png, 60066 bytes]
/work/20260716-234837-aa76/renders/geom/geometry.png — 1400x1000 image/png, 60065 bytes
```

### agent

Geometry is clean: closed surface (0 open/non-manifold edges), correct 0.254 m diameter, rotation axis is clearly z (disk lies in the x-y plane, thin in z). I'll build a snappyHexMesh case with an MRF cylindrical zone around the rotor, axis = z.

### tool: bash

`mkdir -p /work/20260716-234837-aa76/case` exit 0

**input**

```
{
  "cmd": "mkdir -p /work/20260716-234837-aa76/case\ncd /work/20260716-234837-aa76/case\nmkdir -p constant/triSurface system constant/0.orig\ncp /work/geometry/apc_sf_10x4.7_propeller.stl constant/triSurface/propeller.stl\npython3 - <<'EOF'\nimport numpy as np\nD=0.254\nR=D/2\nprint(\"R\", R)\nn_rps=4014/60\nomega=n_rps*2*np.pi\nprint(\"n_rps\",n_rps,\"omega\",omega)\ntipspeed=omega*R\nprint(\"tipspeed\",tipspeed)\nEOF\n"
}
```

**output**

```
exit_code: 0

R 0.127
n_rps 66.9 omega 420.34509705031434
tipspeed 53.38382732538992
```

### tool: write_file

`/work/20260716-234837-aa76/case/system/blockMeshDict`

**input**

```
{
  "path": "/work/20260716-234837-aa76/case/system/blockMeshDict",
  "content": "FoamFile\n{\n    version 2.0;\n    format ascii;\n    class dictionary;\n    object blockMeshDict;\n}\n\n// Outer domain: box, half-extent 0.8 m (~6.3 D radial/axial clearance from rotor)\nconvertToMeters 1;\n\nL 0.8;\n\nvertices\n(\n    (-$L -$L -$L)\n    ( $L -$L -$L)\n    ( $L  $L -$L)\n    (-$L  $L -$L)\n    (-$L -$L  $L)\n    ( $L -$L  $L)\n    ( $L  $L  $L)\n    (-$L  $L  $L)\n);\n\nblocks\n(\n    hex (0 1 2 3 4 5 6 7) (32 32 32) simpleGrading (1 1 1)\n);\n\nedges\n(\n);\n\nboundary\n(\n    farField\n    {\n        type patch;\n        faces\n        (\n            (0 1 2 3)\n            (4 5 6 7)\n            (0 1 5 4)\n            (2 3 7 6)\n            (0 3 7 4)\n            (1 2 6 5)\n        );\n    }\n);\n\nmergePatchPairs\n(\n);\n"
}
```

**output**

```
wrote 699 bytes to /work/20260716-234837-aa76/case/system/blockMeshDict
```

### tool: write_file

`/work/20260716-234837-aa76/case/system/snappyHexMeshDict`

**input**

```
{
  "path": "/work/20260716-234837-aa76/case/system/snappyHexMeshDict",
  "content": "FoamFile\n{\n    version 2.0;\n    format ascii;\n    class dictionary;\n    object snappyHexMeshDict;\n}\n\ncastellatedMesh true;\nsnap            true;\naddLayers       false;\n\ngeometry\n{\n    propeller.stl\n    {\n        type triSurfaceMesh;\n        name propeller;\n    }\n    rotorRegion\n    {\n        type searchableCylinder;\n        point1 (0 0 -0.03);\n        point2 (0 0  0.03);\n        radius 0.16;\n    }\n};\n\ncastellatedMeshControls\n{\n    maxLocalCells 4000000;\n    maxGlobalCells 8000000;\n    minRefinementCells 10;\n    maxLoadUnbalance 0.10;\n    nCellsBetweenLevels 3;\n\n    features\n    (\n    );\n\n    refinementSurfaces\n    {\n        propeller\n        {\n            level (3 3);\n        }\n    }\n\n    resolveFeatureAngle 30;\n\n    refinementRegions\n    {\n        rot...
```

**output**

```
wrote 1918 bytes to /work/20260716-234837-aa76/case/system/snappyHexMeshDict
```

### tool: write_file

`/work/20260716-234837-aa76/case/system/controlDict`

**input**

```
{
  "path": "/work/20260716-234837-aa76/case/system/controlDict",
  "content": "FoamFile\n{\n    version 2.0;\n    format ascii;\n    class dictionary;\n    object controlDict;\n}\n\napplication     MRFSimpleFoam;\n\nstartFrom       latestTime;\nstartTime       0;\nstopAt          endTime;\nendTime         1000;\ndeltaT          1;\nwriteControl    timeStep;\nwriteInterval   100;\npurgeWrite      2;\nwriteFormat     ascii;\nwritePrecision  7;\nwriteCompression off;\ntimeFormat      general;\ntimePrecision   6;\nrunTimeModifiable true;\n\nfunctions\n{\n    forces\n    {\n        type            forces;\n        libs            (forces);\n        writeControl    timeStep;\n        writeInterval   20;\n        patches         (propeller);\n        rho             rhoInf;\n        rhoInf          1.225;\n        CofR            (0 0 0);\n        log             true;\n    }\n\n    #includeFu...
```

**output**

```
wrote 795 bytes to /work/20260716-234837-aa76/case/system/controlDict
```

### tool: write_file

`/work/20260716-234837-aa76/case/system/fvSchemes`

**input**

```
{
  "path": "/work/20260716-234837-aa76/case/system/fvSchemes",
  "content": "FoamFile\n{\n    version 2.0;\n    format ascii;\n    class dictionary;\n    object fvSchemes;\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 linearUpwindV grad(U);\n    div(phi,k)           bounded Gauss upwind;\n    div(phi,omega)       bounded Gauss upwind;\n    div((nuEff*dev2(T(grad(U))))) Gauss linear;\n}\n\nlaplacianSchemes\n{\n    default Gauss linear corrected;\n}\n\ninterpolationSchemes\n{\n    default linear;\n}\n\nsnGradSchemes\n{\n    default corrected;\n}\n\nwallDist\n{\n    method meshWave;\n}\n"
}
```

**output**

```
wrote 608 bytes to /work/20260716-234837-aa76/case/system/fvSchemes
```

### tool: write_file

`/work/20260716-234837-aa76/case/system/fvSolution`

**input**

```
{
  "path": "/work/20260716-234837-aa76/case/system/fvSolution",
  "content": "FoamFile\n{\n    version 2.0;\n    format ascii;\n    class dictionary;\n    object fvSolution;\n}\n\nsolvers\n{\n    p\n    {\n        solver          GAMG;\n        tolerance       1e-7;\n        relTol          0.05;\n        smoother        GaussSeidel;\n    }\n\n    \"(U|k|omega)\"\n    {\n        solver          smoothSolver;\n        smoother        symGaussSeidel;\n        tolerance       1e-8;\n        relTol          0.1;\n    }\n}\n\nSIMPLE\n{\n    nNonOrthogonalCorrectors 1;\n    consistent yes;\n    residualControl\n    {\n        p               1e-5;\n        U               1e-5;\n        \"(k|omega)\"     1e-5;\n    }\n}\n\nrelaxationFactors\n{\n    fields\n    {\n        p 0.3;\n    }\n    equations\n    {\n        U               0.7;\n        \"(k|omega)\"     0.7;\n    }\n}\n"
}
```

**output**

```
wrote 750 bytes to /work/20260716-234837-aa76/case/system/fvSolution
```

### agent

Now let's build the mesh: blockMesh, then decompose and run snappyHexMesh in parallel (few cores).

### tool: bash

`cd /work/20260716-234837-aa76/case && blockMesh > log.blockMesh 2>&1; tail -30...` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && blockMesh > log.blockMesh 2>&1; tail -30 log.blockMesh"
}
```

**output**

```
exit_code: 0

Time   : 15:52:05
Host   : modal
PID    : 8264
I/O    : uncollated
Case   : /work/20260716-234837-aa76/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 static bool Foam::functionObjectList::readFunctionObject(const Foam::string&, Foam::dictionary&, Foam::HashSet<Foam::wordRe>&, const Foam::word&)
    in file db/functionObjects/functionObjectList/functionObjectList.C at line 277
    Cannot find functionObject file residuals

--> FOAM FATAL IO ERROR: (openfoam-2512)
Unexpected '}' while reading dictionary entry

file: system/controlDict at line 42.

    From static bool Foam::entry::New(Foam::dictionary&, Foam::Istream&, inputMode, int)
    in file db/dictionary/entry/entryIO.C at line 156.

FOAM exiting
```

### tool: bash

`cd /work/20260716-234837-aa76/case && sed -i '/#includeFunc residuals/d' syste...` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && sed -i '/#includeFunc residuals/d' system/controlDict && blockMesh > log.blockMesh 2>&1; tail -20 log.blockMesh"
}
```

**output**

```
exit_code: 0

        k : 0.05 .. 0.05

No patch pairs to merge

Writing polyMesh with 0 cellZones
----------------
Mesh Information
----------------
  boundingBox: (-0.8 -0.8 -0.8) (0.8 0.8 0.8)
  nPoints: 35937
  nCells: 32768
  nFaces: 101376
  nInternalFaces: 95232
----------------
Patches
----------------
  patch 0 (start: 95232 size: 6144) name: farField

End
```

### agent

Good. Now decompose and run snappyHexMesh in parallel.

### tool: write_file

`/work/20260716-234837-aa76/case/system/decomposeParDict`

**input**

```
{
  "path": "/work/20260716-234837-aa76/case/system/decomposeParDict",
  "content": "FoamFile\n{\n    version 2.0;\n    format ascii;\n    class dictionary;\n    object decomposeParDict;\n}\n\nnumberOfSubdomains 4;\nmethod scotch;\n"
}
```

**output**

```
wrote 137 bytes to /work/20260716-234837-aa76/case/system/decomposeParDict
```

### tool: bash

`cd /work/20260716-234837-aa76/case && decomposePar -force > log.decomposePar1 ...` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && decomposePar -force > log.decomposePar1 2>&1; tail -15 log.decomposePar1"
}
```

**output**

```
exit_code: 0

Number of processor faces = 2048
Max number of cells = 8192 (0% above average 8192)
Max number of processor patches = 2 (0% above average 2)
Max number of faces between processors = 1024 (0% above average 1024)

Time = 0

Processor 0: field transfer
Processor 1: field transfer
Processor 2: field transfer
Processor 3: field transfer

End
```

### tool: job_start

`cd /work/20260716-234837-aa76/case && mpirun -np 4 snappyHexMesh -parallel -ov...`

**input**

```
{
  "name": "snappy",
  "cmd": "cd /work/20260716-234837-aa76/case && mpirun -np 4 snappyHexMesh -parallel -overwrite > log.snappyHexMesh 2>&1"
}
```

**output**

```
started job afd222c1-045c-44c3-be0d-56259ea57a47 (snappy)
```

### tool: job_check

`job_id=afd222c1-045c-44c3-be0d-56259ea57a47 wait_s=120`

**input**

```
{
  "job_id": "afd222c1-045c-44c3-be0d-56259ea57a47",
  "wait_s": 120
}
```

**output**

```
job afd222c1-045c-44c3-be0d-56259ea57a47 name=snappy status=exited exit_code=0 end_reason=completed log_size=0 ran_for=13s [waited 8s]
log: bytes 0–0, eof=True
```

### tool: bash

`cd /work/20260716-234837-aa76/case && ls -la log.snappyHexMesh; wc -l log.snap...` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && ls -la log.snappyHexMesh; wc -l log.snappyHexMesh; tail -60 log.snappyHexMesh"
}
```

**output**

```
exit_code: 0

-rw-r--r-- 1 root root 38707 Aug 29 15:52 log.snappyHexMesh
1140 log.snappyHexMesh
    faces on cells with determinant < 0.001                : 0
Successfully moved mesh
Moved mesh in = 0.03 s

Repatching faces according to nearest surface ...
Repatched 0 faces in = 0 s

Edge intersection testing:
    Number of edges             : 112042
    Number of edges to retest   : 37004
    Number of intersected edges : 100
Merging 4 sets of faces.

Edge intersection testing:
    Number of edges             : 112036
    Number of edges to retest   : 18
    Number of intersected edges : 94

Undo iteration 0
----------------
Checking faces in error :
    non-orthogonality > 65  degrees                        : 0
    faces with face pyramid volume < 1e-16                 : 0
    faces with concavity > 80  degrees                     : 0
    faces with skewness > 4   (internal) or 20  (boundary) : 0
    faces with interpolation weights (0..1)  < 0.02        : 0
    faces with volume ratio of neighbour cells < 0.01      : 0
    faces with face twist < 0.02                           : 0
    faces on cells with determinant < 0.001                : 0

Merging all points on surface that
- are used by only two boundary faces and
- make an angle with a cosine of more than 0.8660254.

No straight edges simplified and no points removed ...
Snapped mesh : cells:36016  faces:112036  poi
```

### tool: bash

`cd /work/20260716-234837-aa76/case && grep -n -i "cellZone\|Refine\|level\|Add...` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && grep -n -i \"cellZone\\|Refine\\|level\\|Adding points\" log.snappyHexMesh | head -80"
}
```

**output**

```
exit_code: 0

45:Reading refinement surfaces.
46:Read refinement surfaces in = 0.07 s
48:Reading refinement shells.
49:Refinement level 2 for all cells inside rotorRegion
50:Read refinement shells in = 0.02 s
52:Setting refinement level of surface to be consistent with shells.
54:Checked shell refinement in = 0.44 s
74:Cells per refinement level:
76:Setting refinement level of surface to be consistent with curvature.
77:Checked curvature refinement in = 0 s
97:Refinement phase
102:Surface refinement iteration 0
105:Marked for refinement due to surface intersection          : 0 cells.
106:Determined cells to refine in = 0.01 s
107:Selected for refinement : 0 cells (out of 32768)
114:Setting cellZones according to locationsInMesh:
116:    cellZone : none
118:For cellZone none found point (0.4 0.4 0.4) in global region 0 out of 1 regions.
120:    From void Foam::meshRefinement::nearestFace(const Foam::labelUList&, const Foam::bitSet&, Foam::autoPtr<Foam::mapDistribute>&, Foam::labelList&, Foam::label) const
121:    in file meshRefinement/meshRefinement.C at line 526
130:Shell refinement iteration 0
133:Marked for refinement due to distance to explicit features : 0 cells.
134:Marked for refinement due to refinement shells             : 64 cells.
135:Determined cells to refine in = 0.05 s
136:Selected for internal refinement : 64 cells (out of 32768)
141:Refined mesh in = 0.09 s
142
```

### tool: bash

`cd /work/20260716-234837-aa76/case && sed -n '1,120p' log.snappyHexMesh` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && sed -n '1,120p' log.snappyHexMesh"
}
```

**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   : snappyHexMesh -parallel -overwrite
Date   : Aug 29 2026
Time   : 15:52:35
Host   : modal
PID    : 10237
I/O    : uncollated
Case   : /__modal/volumes/vo-wvmvogItm3bZa84GOtUrFp/20260716-234837-aa76/case
nProcs : 4
Hosts  :
(
    (modal 4)
)
Pstream initialized with:
    node communication : off [type=host] (4 ranks, 1 nodes)
    topology controls  : none
    consensus exchange : 0 (tuning: 0)
    exchange algorithm : 0
    commsType          : nonBlocking
    polling iterations : 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)
allowSyste
```

### agent

The mesh generation failed — the propeller surface never got detected (0 intersected edges, 0 repatched faces on the propeller patch). The blade is thin (≈12 mm) relative to the 50 mm background cells, so snappy's edge-intersection detection missed it entirely. I need distance-based refinement around the surface, not just surface-level refinement.

### tool: write_file

`/work/20260716-234837-aa76/case/system/snappyHexMeshDict`

**input**

```
{
  "path": "/work/20260716-234837-aa76/case/system/snappyHexMeshDict",
  "content": "FoamFile\n{\n    version 2.0;\n    format ascii;\n    class dictionary;\n    object snappyHexMeshDict;\n}\n\ncastellatedMesh true;\nsnap            true;\naddLayers       false;\n\ngeometry\n{\n    propeller.stl\n    {\n        type triSurfaceMesh;\n        name propeller;\n    }\n    rotorRegion\n    {\n        type searchableCylinder;\n        point1 (0 0 -0.03);\n        point2 (0 0  0.03);\n        radius 0.16;\n    }\n};\n\ncastellatedMeshControls\n{\n    maxLocalCells 4000000;\n    maxGlobalCells 8000000;\n    minRefinementCells 10;\n    maxLoadUnbalance 0.10;\n    nCellsBetweenLevels 3;\n\n    features\n    (\n    );\n\n    refinementSurfaces\n    {\n        propeller\n        {\n            level (3 3);\n        }\n    }\n\n    resolveFeatureAngle 30;\n\n    refinementRegions\n    {\n        pro...
```

**output**

```
wrote 2024 bytes to /work/20260716-234837-aa76/case/system/snappyHexMeshDict
```

### tool: bash

`cd /work/20260716-234837-aa76/case && rm -rf processor* constant/polyMesh && b...` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && rm -rf processor* constant/polyMesh && blockMesh > log.blockMesh 2>&1 && tail -5 log.blockMesh && decomposePar -force > log.decomposePar1 2>&1 && tail -5 log.decomposePar1"
}
```

**output**

```
exit_code: 0

----------------
  patch 0 (start: 95232 size: 6144) name: farField

End

Processor 2: field transfer
Processor 3: field transfer

End
```

### tool: job_start

`cd /work/20260716-234837-aa76/case && mpirun -np 4 snappyHexMesh -parallel -ov...`

**input**

```
{
  "name": "snappy2",
  "cmd": "cd /work/20260716-234837-aa76/case && mpirun -np 4 snappyHexMesh -parallel -overwrite > log.snappyHexMesh 2>&1"
}
```

**output**

```
started job afaa1a83-dc62-4523-8847-ebcdafb6930c (snappy2)
```

### tool: job_check

`job_id=afaa1a83-dc62-4523-8847-ebcdafb6930c wait_s=120`

**input**

```
{
  "job_id": "afaa1a83-dc62-4523-8847-ebcdafb6930c",
  "wait_s": 120
}
```

**output**

```
job afaa1a83-dc62-4523-8847-ebcdafb6930c name=snappy2 status=exited exit_code=0 end_reason=completed log_size=0 ran_for=14s [waited 8s]
log: bytes 0–0, eof=True
```

### tool: bash

`cd /work/20260716-234837-aa76/case && grep -n "Selected for refinement\|Repatc...` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && grep -n \"Selected for refinement\\|Repatched\\|Snapped mesh\\|Cells per refinement level\" log.snappyHexMesh | tail -30"
}
```

**output**

```
exit_code: 0

77:Cells per refinement level:
110:Selected for refinement : 0 cells (out of 32768)
146:Cells per refinement level:
164:Cells per refinement level:
183:Cells per refinement level:
191:Cells per refinement level:
211:Selected for refinement : 0 cells (out of 38340)
219:Selected for refinement : 0 cells (out of 38340)
227:Selected for refinement : 0 cells (out of 38340)
249:Cells per refinement level:
272:Cells per refinement level:
300:Cells per refinement level:
339:Cells per refinement level:
358:Cells per refinement level:
380:Cells per refinement level:
428:Cells per refinement level:
1139:Repatched 0 faces in = 0 s
1187:Snapped mesh : cells:38270  faces:119622  points:43236  unbalance:0.009772668
1188:Cells per refinement level:
```

### tool: bash

`cd /work/20260716-234837-aa76/case && sed -n '1180,1200p' log.snappyHexMesh; e...` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && sed -n '1180,1200p' log.snappyHexMesh; echo ---; sed -n '180,260p' log.snappyHexMesh"
}
```

**output**

```
exit_code: 0

    faces with face pyramid volume < 1e-16                 : 0
    faces with concavity > 80  degrees                     : 0
    faces with skewness > 4   (internal) or 20  (boundary) : 0
    faces with interpolation weights (0..1)  < 0.02        : 0
    faces with volume ratio of neighbour cells < 0.01      : 0
    faces with face twist < 0.02                           : 0
    faces on cells with determinant < 0.001                : 0
Snapped mesh : cells:38270  faces:119622  points:43236  unbalance:0.009772668
Cells per refinement level:
    0	32536
    1	1514
    2	2514
    3	1706
Writing mesh to time constant
Wrote mesh in = 0.12 s.
Mesh snapped in = 1.42 s.
Checking final mesh ...
Checking faces in error :
    non-orthogonality > 65  degrees                        : 0
    faces with face pyramid volume < 1e-16                 : 0
    faces with concavity > 80  degrees                     : 0
---
    Number of intersected edges : 278
Refined mesh in = 0.07 s
After refinement shell refinement iteration 2 : cells:38340  faces:119688  points:43191  unbalance:0.1289515
Cells per refinement level:
    0	32536
    1	1514
    2	2514
    3	1776
Balancing since max unbalance 0.1289515 is larger than allowable 0.1
Balanced mesh in = 0.24 s
After balancing shell refinement iteration 2 : cells:38340  faces:119688  points:43191  unbalance:0.009598331
Cells per refinement
```

### tool: bash

`cd /work/20260716-234837-aa76/case && grep -n "Removed\|removing\|cellRemoval\...` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && grep -n \"Removed\\|removing\\|cellRemoval\\|Zone\\|region 0 out of\\|patch propeller\\|nCellsUsingFace\\|region.*out of\" log.snappyHexMesh | sed -n '1,60p'"
}
```

**output**

```
exit_code: 0

117:Setting cellZones according to locationsInMesh:
119:    cellZone : none
121:For cellZone none found point (0.4 0.4 0.4) in global region 0 out of 1 regions.
236:Setting cellZones according to locationsInMesh:
238:    cellZone : none
240:For cellZone none found point (0.4 0.4 0.4) in global region 0 out of 6 regions.
277:Setting cellZones according to locationsInMesh:
279:    cellZone : none
281:For cellZone none found point (0.4 0.4 0.4) in global region 0 out of 8 regions.
309:Setting cellZones according to locationsInMesh:
311:    cellZone : none
313:For cellZone none found point (0.4 0.4 0.4) in global region 0 out of 1 regions.
314:Setting faceZones according to neighbouring cellZones:
326:Setting cellZones according to locationsInMesh:
328:    cellZone : none
330:For cellZone none found point (0.4 0.4 0.4) in global region 0 out of 1 regions.
363:Setting cellZones according to locationsInMesh:
365:    cellZone : none
367:For cellZone none found point (0.4 0.4 0.4) in global region 0 out of 1 regions.
440:Duplicating 0 points on faceZones of type boundary
```

### tool: bash

`cd /work/20260716-234837-aa76/case && grep -n -i "patch\b" log.snappyHexMesh |...` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && grep -n -i \"patch\\b\" log.snappyHexMesh | tail -30"
}
```

**output**

```
exit_code: 0

86:Patch Type                Region                        
476:Smoothing patch points ...
525:Patch points smoothed in = 0.12 s
544:   multi-patch features : false
564:--> FOAM Warning : Displacement (7.460203e-06 2.922287e-06 3.529594e-05) at mesh point 3777 coord (-0.002347039 0.05000531 2.130672e-07) points through the surrounding patch faces
605:   multi-patch features : false
625:--> FOAM Warning : Displacement (2.558243e-05 4.468121e-06 5.848524e-05) at mesh point 3777 coord (-0.002339579 0.05000823 3.550901e-05) points through the surrounding patch faces
666:   multi-patch features : false
686:--> FOAM Warning : Displacement (4.336235e-05 4.803549e-06 6.969156e-05) at mesh point 3777 coord (-0.002313997 0.0500127 9.399425e-05) points through the surrounding patch faces
727:   multi-patch features : false
747:--> FOAM Warning : Displacement (6.65515e-05 5.911076e-06 6.881942e-05) at mesh point 3777 coord (-0.002270634 0.0500175 0.0001636858) points through the surrounding patch faces
788:   multi-patch features : false
808:--> FOAM Warning : Displacement (9.186704e-05 5.968088e-06 6.441019e-05) at mesh point 3777 coord (-0.002204083 0.05002342 0.0002325052) points through the surrounding patch faces
849:   multi-patch features : false
869:--> FOAM Warning : Displacement (0.0001074558 5.744338e-06 6.688645e-05) at mesh point 3777 coord (-0.002112216 0.050029
```

### agent

Let's just reconstruct and check the mesh directly with checkMesh — that will tell us patch face counts and mesh quality definitively.

### tool: job_start

`cd /work/20260716-234837-aa76/case && reconstructParMesh -constant > log.recon...`

**input**

```
{
  "name": "reconstruct_check",
  "cmd": "cd /work/20260716-234837-aa76/case && reconstructParMesh -constant > log.reconstructParMesh 2>&1; checkMesh -allTopology -allGeometry > log.checkMesh 2>&1"
}
```

**output**

```
started job b7ade6bb-e337-4369-a329-a7b70427d2ed (reconstruct_check)
```

### tool: job_check

`job_id=b7ade6bb-e337-4369-a329-a7b70427d2ed wait_s=60`

**input**

```
{
  "job_id": "b7ade6bb-e337-4369-a329-a7b70427d2ed",
  "wait_s": 60
}
```

**output**

```
job b7ade6bb-e337-4369-a329-a7b70427d2ed name=reconstruct_check status=exited exit_code=0 end_reason=completed log_size=0 ran_for=5s
log: bytes 0–0, eof=True
```

### tool: bash

`cd /work/20260716-234837-aa76/case && cat log.checkMesh | sed -n '1,120p'` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && cat log.checkMesh | sed -n '1,120p'"
}
```

**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   : checkMesh -allTopology -allGeometry
Date   : Aug 29 2026
Time   : 15:55:57
Host   : modal
PID    : 18013
I/O    : uncollated
Case   : /work/20260716-234837-aa76/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 static Foam::instantList Foam::timeSelector::select0(Foam::Time&, const Foam::argList&)
    in file db/Time/timeSelector.C at
```

### tool: bash

`cd /work/20260716-234837-aa76/case && sed -n '120,200p' log.checkMesh` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && sed -n '120,200p' log.checkMesh"
}
```

**output**

```
exit_code: 0

    Face interpolation weight check OK.
    Face volume ratio : minimum: 0.1085803 average: 0.9634045
    Face volume ratio check OK.

Failed 2 mesh checks.

End
```

### tool: bash

`which MRFSimpleFoam simpleFoam 2>&1; echo ---` exit 0

**input**

```
{
  "cmd": "which MRFSimpleFoam simpleFoam 2>&1; echo ---\nfind $FOAM_TUTORIALS -iname \"*MRF*\" -maxdepth 4 | head -20\necho ---\nfind $FOAM_TUTORIALS -path \"*propeller*\" -o -iname \"*rotor*\" 2>/dev/null | grep -i -E \"propell|rotor\" | head -30"
}
```

**output**

```
exit_code: 0

/usr/lib/openfoam/openfoam2512/platforms/linux64GccDPInt32Opt/bin/simpleFoam
---
/usr/lib/openfoam/openfoam2512/tutorials/resources/geometry/cpuCabinet/MRF_region.obj.gz
/usr/lib/openfoam/openfoam2512/tutorials/resources/geometry/rigidBodyHull/MRF_REGION.obj.gz
---
/usr/lib/openfoam/openfoam2512/tutorials/compressible/overRhoPimpleDyMFoam/twoSimpleRotors
/usr/lib/openfoam/openfoam2512/tutorials/incompressible/SRFPimpleFoam/rotor2D
/usr/lib/openfoam/openfoam2512/tutorials/incompressible/overPimpleDyMFoam/simpleRotor
/usr/lib/openfoam/openfoam2512/tutorials/incompressible/overPimpleDyMFoam/twoSimpleRotors
/usr/lib/openfoam/openfoam2512/tutorials/incompressible/pimpleFoam/RAS/propeller
/usr/lib/openfoam/openfoam2512/tutorials/incompressible/pimpleFoam/RAS/propeller/0.orig
/usr/lib/openfoam/openfoam2512/tutorials/incompressible/pimpleFoam/RAS/propeller/0.orig/U
/usr/lib/openfoam/openfoam2512/tutorials/incompressible/pimpleFoam/RAS/propeller/0.orig/epsilon
/usr/lib/openfoam/openfoam2512/tutorials/incompressible/pimpleFoam/RAS/propeller/0.orig/k
/usr/lib/openfoam/openfoam2512/tutorials/incompressible/pimpleFoam/RAS/propeller/0.orig/nut
/usr/lib/openfoam/openfoam2512/tutorials/incompressible/pimpleFoam/RAS/propeller/0.orig/p
/usr/lib/openfoam/openfoam2512/tutorials/incompressible/pimpleFoam/RAS/propeller/Allclean
/usr/lib/openfoam/openfoam2512/tutorials/incompressible/pi
```

### tool: bash

`find $FOAM_TUTORIALS -iname "fvModels" | xargs grep -l "MRF" 2>/dev/null | hea...` exit 0

**input**

```
{
  "cmd": "find $FOAM_TUTORIALS -iname \"fvModels\" | xargs grep -l \"MRF\" 2>/dev/null | head -10"
}
```

**output**

```
exit_code: 0
```

### tool: bash

`find $FOAM_TUTORIALS -iname "MRFProperties" 2>/dev/null | head; echo ---` exit 0

**input**

```
{
  "cmd": "find $FOAM_TUTORIALS -iname \"MRFProperties\" 2>/dev/null | head; echo ---\nfind $FOAM_TUTORIALS -path \"*mixerVessel*\" | head -30\necho ---\nfind $FOAM_TUTORIALS -iname \"*MRF*\" 2>/dev/null"
}
```

**output**

```
exit_code: 0

/usr/lib/openfoam/openfoam2512/tutorials/compressible/rhoPimpleFoam/RAS/mixerVessel2D/constant/MRFProperties
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/cpuCabinet/constant/domain0/MRFProperties
/usr/lib/openfoam/openfoam2512/tutorials/heatTransfer/chtMultiRegionSimpleFoam/heatExchanger/constant/air/MRFProperties
/usr/lib/openfoam/openfoam2512/tutorials/incompressible/simpleFoam/mixerVessel2D/constant/MRFProperties
/usr/lib/openfoam/openfoam2512/tutorials/incompressible/simpleFoam/rotatingCylinders/constant/MRFProperties
/usr/lib/openfoam/openfoam2512/tutorials/multiphase/driftFluxFoam/RAS/mixerVessel2D/constant/MRFProperties
/usr/lib/openfoam/openfoam2512/tutorials/multiphase/interFoam/laminar/mixerVessel2D/constant/MRFProperties
/usr/lib/openfoam/openfoam2512/tutorials/multiphase/multiphaseEulerFoam/mixerVessel2D/constant/MRFProperties
/usr/lib/openfoam/openfoam2512/tutorials/multiphase/multiphaseInterFoam/laminar/mixerVessel2D/constant/MRFProperties
/usr/lib/openfoam/openfoam2512/tutorials/multiphase/reactingMultiphaseEulerFoam/laminar/mixerVessel2D/constant/MRFProperties
---
/usr/lib/openfoam/openfoam2512/tutorials/compressible/rhoPimpleFoam/RAS/mixerVessel2D
/usr/lib/openfoam/openfoam2512/tutorials/compressible/rhoPimpleFoam/RAS/mixerVessel2D/0.orig
/usr/lib/openfoam/openfoam2512/tutorials/compressible/rhoPimpleFoam/RAS/mixe
```

### agent

Good — MRF stays as a `constant/MRFProperties` used by plain `simpleFoam` in this version. Let's copy the exact structure from the mixerVessel2D tutorial.

### tool: bash

`cat /usr/lib/openfoam/openfoam2512/tutorials/incompressible/simpleFoam/mixerVe...` exit 1

**input**

```
{
  "cmd": "cat /usr/lib/openfoam/openfoam2512/tutorials/incompressible/simpleFoam/mixerVessel2D/constant/MRFProperties\necho ---topoSet---\ncat /usr/lib/openfoam/openfoam2512/tutorials/incompressible/simpleFoam/mixerVessel2D/system/topoSetDict 2>/dev/null\necho ---fvOptions\ncat /usr/lib/openfoam/openfoam2512/tutorials/incompressible/simpleFoam/mixerVessel2D/constant/fvOptions 2>/dev/null\necho ---controlDict libs\ngrep -n \"libs\\|MRF\" /usr/lib/openfoam/openfoam2512/tutorials/incompressible/simpleFoam/mixerVessel2D/system/controlDict"
}
```

**output**

```
exit_code: 1

/*--------------------------------*- 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      MRFProperties;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

MRF1
{
    cellZone    rotor;
    active      yes;

    // Fixed patches (by default they 'move' with the MRF zone)
    nonRotatingPatches ();

    origin    (0 0 0);
    axis      (0 0 1);
    omega     104.72;
}

// ************************************************************************* //
---topoSet---
---fvOptions
---controlDict libs
```

### tool: bash

`D=/usr/lib/openfoam/openfoam2512/tutorials/incompressible/simpleFoam/mixerVess...` exit 0

**input**

```
{
  "cmd": "D=/usr/lib/openfoam/openfoam2512/tutorials/incompressible/simpleFoam/mixerVessel2D\ncat $D/Allrun 2>/dev/null\necho --- blockMeshDict cellZone\ngrep -n -A3 \"cellZone\\|Zone\" $D/system/blockMeshDict 2>/dev/null | head -30"
}
```

**output**

```
exit_code: 0

#!/bin/sh
cd "${0%/*}" || exit                                # Run from this directory
. ${WM_PROJECT_DIR:?}/bin/tools/RunFunctions        # Tutorial run functions
#------------------------------------------------------------------------------

restore0Dir

m4 system/blockMeshDict.m4 > system/blockMeshDict
runApplication blockMesh

runApplication $(getApplication)

#------------------------------------------------------------------------------
--- blockMeshDict cellZone
```

### tool: bash

`D=/usr/lib/openfoam/openfoam2512/tutorials/incompressible/simpleFoam/mixerVess...` exit 0

**input**

```
{
  "cmd": "D=/usr/lib/openfoam/openfoam2512/tutorials/incompressible/simpleFoam/mixerVessel2D\ngrep -n \"rotor\" $D/system/blockMeshDict.m4"
}
```

**output**

```
exit_code: 0

427:    rotor
433:    rotor
439:    rotor
445:    rotor
451:    rotor
457:    rotor
463:    rotor
469:    rotor
475:    rotor
481:    rotor
487:    rotor
493:    rotor
499:    rotor
505:    rotor
511:    rotor
517:    rotor
697:    wall rotor
```

### agent

That uses named blocks in blockMesh. For our snapped mesh, I'll use `topoSet` with `cylinderToCell` to create the `rotor` cellZone, which is the standard approach for MRF with snappyHexMesh geometries.

### tool: write_file

`/work/20260716-234837-aa76/case/system/topoSetDict`

**input**

```
{
  "path": "/work/20260716-234837-aa76/case/system/topoSetDict",
  "content": "FoamFile\n{\n    version 2.0;\n    format ascii;\n    class dictionary;\n    object topoSetDict;\n}\n\nactions\n(\n    {\n        name    rotor;\n        type    cellSet;\n        action  new;\n        source  cylinderToCell;\n        p1      (0 0 -0.03);\n        p2      (0 0  0.03);\n        radius  0.16;\n    }\n    {\n        name    rotor;\n        type    cellZoneSet;\n        action  new;\n        source  setToCellZone;\n        set     rotor;\n    }\n);\n"
}
```

**output**

```
wrote 440 bytes to /work/20260716-234837-aa76/case/system/topoSetDict
```

### tool: write_file

`/work/20260716-234837-aa76/case/constant/MRFProperties`

**input**

```
{
  "path": "/work/20260716-234837-aa76/case/constant/MRFProperties",
  "content": "FoamFile\n{\n    version 2.0;\n    format ascii;\n    class dictionary;\n    object MRFProperties;\n}\n\nMRF1\n{\n    cellZone           rotor;\n    active             yes;\n\n    nonRotatingPatches ();\n\n    origin             (0 0 0);\n    axis               (0 0 1);\n    omega              420.345; // 4014 rpm = 420.345 rad/s\n}\n"
}
```

**output**

```
wrote 317 bytes to /work/20260716-234837-aa76/case/constant/MRFProperties
```

### agent

Now transportProperties, turbulenceProperties, controlDict application fix, and 0 fields with freestream (static/quiescent) BCs.

### tool: write_file

`/work/20260716-234837-aa76/case/constant/transportProperties`

**input**

```
{
  "path": "/work/20260716-234837-aa76/case/constant/transportProperties",
  "content": "FoamFile\n{\n    version 2.0;\n    format ascii;\n    class dictionary;\n    object transportProperties;\n}\n\ntransportModel Newtonian;\nnu              1.5e-05;\n"
}
```

**output**

```
wrote 154 bytes to /work/20260716-234837-aa76/case/constant/transportProperties
```

### tool: write_file

`/work/20260716-234837-aa76/case/constant/turbulenceProperties`

**input**

```
{
  "path": "/work/20260716-234837-aa76/case/constant/turbulenceProperties",
  "content": "FoamFile\n{\n    version 2.0;\n    format ascii;\n    class dictionary;\n    object turbulenceProperties;\n}\n\nsimulationType RAS;\n\nRAS\n{\n    RASModel        kOmegaSST;\n    turbulence      on;\n    printCoeffs     on;\n}\n"
}
```

**output**

```
wrote 212 bytes to /work/20260716-234837-aa76/case/constant/turbulenceProperties
```

### tool: bash

`cd /work/20260716-234837-aa76/case && sed -i 's/application MRFSimpleFoam;...` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && sed -i 's/application     MRFSimpleFoam;/application     simpleFoam;/' system/controlDict && grep application system/controlDict"
}
```

**output**

```
exit_code: 0

application     simpleFoam;
```

### tool: bash

`D=/usr/lib/openfoam/openfoam2512/tutorials/incompressible/pimpleFoam/RAS/prope...` exit 0

**input**

```
{
  "cmd": "D=/usr/lib/openfoam/openfoam2512/tutorials/incompressible/pimpleFoam/RAS/propeller\ncat $D/0.orig/U\necho ---P---\ncat $D/0.orig/p"
}
```

**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       volVectorField;
    object      U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

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

internalField   uniform (0 0 0);

boundaryField
{
    #includeEtc "caseDicts/setConstraintTypes"

    inlet
    {
        type            fixedValue;
        value           uniform (0 -5 0);
    }

    outlet
    {
        type            inletOutlet;
        inletValue      uniform (0 0 0);
        value           uniform (0 0 0);
    }

    outerCylinder
    {
        type            noSlip;
    }

    "propeller.*"
    {
        type            movingWallVelocity;
        value           uniform (0 0 0);
    }
}

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

### tool: bash

`find /usr/lib/openfoam/openfoam2512/tutorials -name "*.orig" -exec grep -l "fr...` exit 0

**input**

```
{
  "cmd": "find /usr/lib/openfoam/openfoam2512/tutorials -name \"*.orig\" -exec grep -l \"freestream\" {} \\; -path \"*U*\" 2>/dev/null | head\ngrep -rl \"freestreamPressure\" /usr/lib/openfoam/openfoam2512/tutorials/ 2>/dev/null | head -5"
}
```

**output**

```
exit_code: 0
[took 10s]

/usr/lib/openfoam/openfoam2512/tutorials/compressible/rhoPimpleFoam/RAS/aerofoilNACA0012/0.orig/p
/usr/lib/openfoam/openfoam2512/tutorials/compressible/rhoSimpleFoam/aerofoilNACA0012/0.orig/p
/usr/lib/openfoam/openfoam2512/tutorials/incompressible/simpleFoam/airFoil2D/0.orig/p
```

### tool: bash

`D=/usr/lib/openfoam/openfoam2512/tutorials/incompressible/simpleFoam/airFoil2D` exit 0

**input**

```
{
  "cmd": "D=/usr/lib/openfoam/openfoam2512/tutorials/incompressible/simpleFoam/airFoil2D\ncat $D/0.orig/p\necho --- U ---\ncat $D/0.orig/U"
}
```

**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       volScalarField;
    object      p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

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

internalField   uniform 0;

boundaryField
{
    inlet
    {
        type            freestreamPressure;
        freestreamValue $internalField;
    }

    outlet
    {
        type            freestreamPressure;
        freestreamValue $internalField;
    }

    walls
    {
        type            zeroGradient;
    }

    frontAndBack
    {
        type            empty;
    }
}

// ************************************************************************* //
--- U ---
/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |
```

### agent

Good — freestream BC pair confirmed available. For our static (hover) case, freestreamValue = (0 0 0) for U and 0 for p (gauge).

### tool: write_file

`/work/20260716-234837-aa76/case/0.orig/U`

**input**

```
{
  "path": "/work/20260716-234837-aa76/case/0.orig/U",
  "content": "FoamFile\n{\n    version 2.0;\n    format ascii;\n    class volVectorField;\n    object U;\n}\n\ndimensions      [0 1 -1 0 0 0 0];\n\ninternalField   uniform (0 0 0);\n\nboundaryField\n{\n    farField\n    {\n        type            freestreamVelocity;\n        freestreamValue uniform (0 0 0);\n    }\n\n    propeller\n    {\n        type            noSlip;\n    }\n}\n"
}
```

**output**

```
wrote 345 bytes to /work/20260716-234837-aa76/case/0.orig/U
```

### tool: write_file

`/work/20260716-234837-aa76/case/0.orig/p`

**input**

```
{
  "path": "/work/20260716-234837-aa76/case/0.orig/p",
  "content": "FoamFile\n{\n    version 2.0;\n    format ascii;\n    class volScalarField;\n    object p;\n}\n\ndimensions      [0 2 -2 0 0 0 0];\n\ninternalField   uniform 0;\n\nboundaryField\n{\n    farField\n    {\n        type            freestreamPressure;\n        freestreamValue uniform 0;\n    }\n\n    propeller\n    {\n        type            zeroGradient;\n    }\n}\n"
}
```

**output**

```
wrote 339 bytes to /work/20260716-234837-aa76/case/0.orig/p
```

### tool: write_file

`/work/20260716-234837-aa76/case/0.orig/k`

**input**

```
{
  "path": "/work/20260716-234837-aa76/case/0.orig/k",
  "content": "FoamFile\n{\n    version 2.0;\n    format ascii;\n    class volScalarField;\n    object k;\n}\n\ndimensions      [0 2 -2 0 0 0 0];\n\ninternalField   uniform 0.05;\n\nboundaryField\n{\n    farField\n    {\n        type            inletOutlet;\n        inletValue      uniform 0.05;\n        value           uniform 0.05;\n    }\n\n    propeller\n    {\n        type            kqRWallFunction;\n        value           uniform 0.05;\n    }\n}\n"
}
```

**output**

```
wrote 417 bytes to /work/20260716-234837-aa76/case/0.orig/k
```

### tool: write_file

`/work/20260716-234837-aa76/case/0.orig/k`

**input**

```
{
  "path": "/work/20260716-234837-aa76/case/0.orig/k",
  "content": "FoamFile\n{\n    version 2.0;\n    format ascii;\n    class volScalarField;\n    object k;\n}\n\ndimensions      [0 2 -2 0 0 0 0];\n\ninternalField   uniform 0.001;\n\nboundaryField\n{\n    farField\n    {\n        type            inletOutlet;\n        inletValue      uniform 0.001;\n        value           uniform 0.001;\n    }\n\n    propeller\n    {\n        type            kqRWallFunction;\n        value           uniform 0.001;\n    }\n}\n"
}
```

**output**

```
wrote 421 bytes to /work/20260716-234837-aa76/case/0.orig/k
```

### tool: write_file

`/work/20260716-234837-aa76/case/0.orig/omega`

**input**

```
{
  "path": "/work/20260716-234837-aa76/case/0.orig/omega",
  "content": "FoamFile\n{\n    version 2.0;\n    format ascii;\n    class volScalarField;\n    object omega;\n}\n\ndimensions      [0 0 -1 0 0 0 0];\n\ninternalField   uniform 50;\n\nboundaryField\n{\n    farField\n    {\n        type            inletOutlet;\n        inletValue      uniform 50;\n        value           uniform 50;\n    }\n\n    propeller\n    {\n        type            omegaWallFunction;\n        value           uniform 50;\n    }\n}\n"
}
```

**output**

```
wrote 415 bytes to /work/20260716-234837-aa76/case/0.orig/omega
```

### tool: write_file

`/work/20260716-234837-aa76/case/0.orig/nut`

**input**

```
{
  "path": "/work/20260716-234837-aa76/case/0.orig/nut",
  "content": "FoamFile\n{\n    version 2.0;\n    format ascii;\n    class volScalarField;\n    object nut;\n}\n\ndimensions      [0 2 -1 0 0 0 0];\n\ninternalField   uniform 0;\n\nboundaryField\n{\n    farField\n    {\n        type            calculated;\n        value           uniform 0;\n    }\n\n    propeller\n    {\n        type            nutkWallFunction;\n        value           uniform 0;\n    }\n}\n"
}
```

**output**

```
wrote 372 bytes to /work/20260716-234837-aa76/case/0.orig/nut
```

### agent

Now render the mesh before doing anything else, run topoSet to create the MRF zone, then copy 0.orig to 0.

### tool: bash

`cd /work/20260716-234837-aa76/case && topoSet -dict system/topoSetDict > log.t...` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && topoSet -dict system/topoSetDict > log.topoSet 2>&1; tail -20 log.topoSet\necho ---\ncheckMesh -cellSets 2>&1 | tail -5 || true"
}
```

**output**

```
exit_code: 0

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

Create polyMesh for time = 0

Reading topoSetDict

Time = 0
    mesh not changed.
Created cellSet rotor
    Applying source cylinderToCell
    Adding cells with centres within cylinder, with point1 = (0 0 -0.03), point2 = (0 0 0.03), radius = 0.16
    cellSet rotor now size 3484
Created cellZoneSet rotor
    Applying source setToCellZone
    Adding all cells from cell set: rotor ...
    cellZoneSet rotor now size 3484

End

---
Invalid option: -cellSets

See 'checkMesh -help' for usage
 or 'checkMesh -help-full' for extended usage
```

### agent

3484 cells assigned to the rotor zone. Now let's render the mesh (geometry + cut planes) before running anything.

### tool: bash

`cd /work/20260716-234837-aa76/case && rm -rf 0 && cp -r 0.orig 0` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && rm -rf 0 && cp -r 0.orig 0\ntouch case.foam\npython3 /work/.toolbox/render.py . --scene mesh --out /work/20260716-234837-aa76/renders/mesh 2>&1 | tail -40"
}
```

**output**

```
exit_code: 0

time 0  (available: 0)
cells 38,270  points 43,236
/work/20260716-234837-aa76/renders/mesh/mesh_z.png
```

### tool: read_file

`/work/20260716-234837-aa76/renders/mesh/mesh_z.png`

**input**

```
{
  "path": "/work/20260716-234837-aa76/renders/mesh/mesh_z.png"
}
```

**output**

```
[image/png, 85596 bytes]
/work/20260716-234837-aa76/renders/mesh/mesh_z.png — 1100x800 image/png, 85595 bytes
```

### tool: bash

`cd /work/20260716-234837-aa76/case && python3 /work/.toolbox/render.py . --sce...` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && python3 /work/.toolbox/render.py . --scene mesh --normal x --out /work/20260716-234837-aa76/renders/mesh 2>&1 | tail -10\npython3 /work/.toolbox/render.py . --scene mesh --normal y --out /work/20260716-234837-aa76/renders/mesh 2>&1 | tail -10\nls /work/20260716-234837-aa76/renders/mesh"
}
```

**output**

```
exit_code: 0

time 0  (available: 0)
cells 38,270  points 43,236
/work/20260716-234837-aa76/renders/mesh/mesh_x.png
time 0  (available: 0)
cells 38,270  points 43,236
/work/20260716-234837-aa76/renders/mesh/mesh_y.png
mesh_x.png
mesh_y.png
mesh_z.png
```

### tool: read_file

`/work/20260716-234837-aa76/renders/mesh/mesh_x.png`

**input**

```
{
  "path": "/work/20260716-234837-aa76/renders/mesh/mesh_x.png"
}
```

**output**

```
[image/png, 71115 bytes]
/work/20260716-234837-aa76/renders/mesh/mesh_x.png — 1100x800 image/png, 71115 bytes
```

### agent

Good — this confirms the refinement bands (cylinder + surface) sit correctly around the thin rotor disk, and background mesh is uniform coarse elsewhere. This matches the intended MRF zone placement. Let's look at the y-cut too.

### tool: read_file

`/work/20260716-234837-aa76/renders/mesh/mesh_y.png`

**input**

```
{
  "path": "/work/20260716-234837-aa76/renders/mesh/mesh_y.png"
}
```

**output**

```
[image/png, 71613 bytes]
/work/20260716-234837-aa76/renders/mesh/mesh_y.png — 1100x800 image/png, 71611 bytes
```

### tool: bash

`cd /work/20260716-234837-aa76/case && rm -rf processor*` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && rm -rf processor*\ndecomposePar -force > log.decomposePar2 2>&1; tail -15 log.decomposePar2"
}
```

**output**

```
exit_code: 0

Number of processor faces = 2439
Max number of cells = 9644 (0.7995819% above average 9567.5)
Max number of processor patches = 3 (0% above average 3)
Max number of faces between processors = 1285 (5.371054% above average 1219.5)

Time = 0

Processor 0: field transfer
Processor 1: field transfer
Processor 2: field transfer
Processor 3: field transfer

End
```

### agent

Now let's run simpleFoam. Given MRF steady-state, I'll run up to ~1000 iterations (residualControl may stop earlier) on 4 cores.

### tool: job_start

`cd /work/20260716-234837-aa76/case && mpirun -np 4 simpleFoam -parallel > log....`

**input**

```
{
  "name": "simpleFoam_run",
  "cmd": "cd /work/20260716-234837-aa76/case && mpirun -np 4 simpleFoam -parallel > log.simpleFoam 2>&1"
}
```

**output**

```
started job 2190d00f-684c-43e0-a376-9aef9bf8173f (simpleFoam_run)
```

### tool: job_check

`job_id=2190d00f-684c-43e0-a376-9aef9bf8173f wait_s=120`

**input**

```
{
  "job_id": "2190d00f-684c-43e0-a376-9aef9bf8173f",
  "wait_s": 120
}
```

**output**

```
job 2190d00f-684c-43e0-a376-9aef9bf8173f name=simpleFoam_run status=exited exit_code=136 end_reason=failed log_size=0 ran_for=6s
log: bytes 0–0, eof=True
```

### tool: bash

`cd /work/20260716-234837-aa76/case && tail -80 log.simpleFoam` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && tail -80 log.simpleFoam"
}
```

**output**

```
exit_code: 0

[modal:32831] Signal: Floating point exception (8)
[modal:32831] Signal code:  (-6)
[modal:32831] Failing at address: 0x803f
[modal:32831] [ 0] /lib/x86_64-linux-gnu/libc.so.6(+0x45330)[0x2b02dc3db330]
[modal:32831] [ 1] /lib/x86_64-linux-gnu/libc.so.6(pthread_kill+0x11c)[0x2b02dc434b2c]
[modal:32831] [ 2] /lib/x86_64-linux-gnu/libc.so.6(gsignal+0x1e)[0x2b02dc3db27e]
[modal:32831] [ 3] /lib/x86_64-linux-gnu/libc.so.6(+0x45330)[0x2b02dc3db330]
[modal:32831] [ 4] /usr/lib/openfoam/openfoam2512/platforms/linux64GccDPInt32Opt/lib/libOpenFOAM.so(_ZN4Foam6divideERNS_5FieldIdEERKNS_5UListIdEES6_+0x25)[0x2b02dbd1c3c5]
[modal:32831] [ 5] /usr/lib/openfoam/openfoam2512/platforms/linux64GccDPInt32Opt/lib/libOpenFOAM.so(_ZN4FoamdvERKNS_3tmpINS_5FieldIdEEEES5_+0xa3)[0x2b02dbd1fa43]
[modal:32831] [ 6] /usr/lib/openfoam/openfoam2512/platforms/linux64GccDPInt32Opt/lib/libfiniteVolume.so(_ZN4Foam36freestreamVelocityFvPatchVectorField12updateCoeffsEv+0xda)[0x2b02d96f5c8a]
 in  in /usr/lib/openfoam/openfoam2512/platforms/linux64GccDPInt32Opt/bin/simpleFoam
[1] =============
[modal:32832] *** Process received signal ***
[modal:32832] Signal: Floating point exception (8)
[modal:32832] Signal code:  (-6)
[modal:32832] Failing at address: 0x8040
/usr/lib/openfoam/openfoam2512/platforms/linux64GccDPInt32Opt/bin/simpleFoam
[3] =============
[modal:32834] *** Process received signal ***
[m
```

### agent

The `freestreamVelocity` BC divides by the freestream speed magnitude to get a flow direction — with a **static** (zero freestream) condition that's a division by zero, which is exactly what crashed. I'll switch to the standard hover/static combo: `pressureInletOutletVelocity` + `totalPressure`(p0=0), which handles zero far-field speed cleanly.

### tool: write_file

`/work/20260716-234837-aa76/case/0.orig/U`

**input**

```
{
  "path": "/work/20260716-234837-aa76/case/0.orig/U",
  "content": "FoamFile\n{\n    version 2.0;\n    format ascii;\n    class volVectorField;\n    object U;\n}\n\ndimensions      [0 1 -1 0 0 0 0];\n\ninternalField   uniform (0 0 0);\n\nboundaryField\n{\n    farField\n    {\n        type            pressureInletOutletVelocity;\n        inletValue      uniform (0 0 0);\n        value           uniform (0 0 0);\n    }\n\n    propeller\n    {\n        type            noSlip;\n    }\n}\n"
}
```

**output**

```
wrote 395 bytes to /work/20260716-234837-aa76/case/0.orig/U
```

### tool: write_file

`/work/20260716-234837-aa76/case/0.orig/p`

**input**

```
{
  "path": "/work/20260716-234837-aa76/case/0.orig/p",
  "content": "FoamFile\n{\n    version 2.0;\n    format ascii;\n    class volScalarField;\n    object p;\n}\n\ndimensions      [0 2 -2 0 0 0 0];\n\ninternalField   uniform 0;\n\nboundaryField\n{\n    farField\n    {\n        type            totalPressure;\n        p0              uniform 0;\n        gamma           1;\n        value           uniform 0;\n    }\n\n    propeller\n    {\n        type            zeroGradient;\n    }\n}\n"
}
```

**output**

```
wrote 396 bytes to /work/20260716-234837-aa76/case/0.orig/p
```

### tool: bash

`cd /work/20260716-234837-aa76/case && rm -rf 0 processor*` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && rm -rf 0 processor*\ncp -r 0.orig 0\ndecomposePar -force > log.decomposePar3 2>&1; tail -5 log.decomposePar3"
}
```

**output**

```
exit_code: 0

Processor 2: field transfer
Processor 3: field transfer

End
```

### tool: job_start

`cd /work/20260716-234837-aa76/case && mpirun -np 4 simpleFoam -parallel > log....`

**input**

```
{
  "name": "simpleFoam_run2",
  "cmd": "cd /work/20260716-234837-aa76/case && mpirun -np 4 simpleFoam -parallel > log.simpleFoam 2>&1"
}
```

**output**

```
started job dbef3125-0dd6-4bd4-8f83-d0648f0ebb23 (simpleFoam_run2)
```

### tool: job_check

`job_id=dbef3125-0dd6-4bd4-8f83-d0648f0ebb23 wait_s=120`

**input**

```
{
  "job_id": "dbef3125-0dd6-4bd4-8f83-d0648f0ebb23",
  "wait_s": 120
}
```

**output**

```
job dbef3125-0dd6-4bd4-8f83-d0648f0ebb23 name=simpleFoam_run2 status=exited exit_code=0 end_reason=completed log_size=0 ran_for=1.4min [waited 76s]
log: bytes 0–0, eof=True
```

### agent

It ran to completion. Let's check convergence and residuals.

### tool: bash

`cd /work/20260716-234837-aa76/case && tail -60 log.simpleFoam` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && tail -60 log.simpleFoam"
}
```

**output**

```
exit_code: 0

smoothSolver:  Solving for omega, Initial residual = 0.0005847137, Final residual = 1.030963e-05, No Iterations 2
smoothSolver:  Solving for k, Initial residual = 0.0003394559, Final residual = 7.684326e-06, No Iterations 2
ExecutionTime = 63.02 s  ClockTime = 75 s

forces forces write:
    Sum of forces
        Total    : (-0.001586325 -0.0007441711 0.9570391)
        Pressure : (-0.001614148 -0.0005759942 0.9585148)
        Viscous  : (2.782225e-05 -0.0001681769 -0.001475715)
    Sum of moments
        Total    : (5.535784e-05 -4.938162e-05 -0.02477286)
        Pressure : (5.484586e-05 -4.845309e-05 -0.02350753)
        Viscous  : (5.119817e-07 -9.285232e-07 -0.001265332)
Time = 999

smoothSolver:  Solving for Ux, Initial residual = 0.002583811, Final residual = 0.0001362358, No Iterations 2
smoothSolver:  Solving for Uy, Initial residual = 0.002853475, Final residual = 0.0001448118, No Iterations 2
smoothSolver:  Solving for Uz, Initial residual = 0.002434508, Final residual = 0.0001047081, No Iterations 2
GAMG:  Solving for p, Initial residual = 0.0001316538, Final residual = 4.145025e-06, No Iterations 3
GAMG:  Solving for p, Initial residual = 1.005909e-05, Final residual = 3.13852e-07, No Iterations 3
time step continuity errors : sum local = 4.459134e-05, global = 4.859768e-06, cumulative = 0.004468578
smoothSolver:  Solving for omega, Initial residual = 0
```

### tool: bash

`cd /work/20260716-234837-aa76/case && tail -3 postProcessing/forces/0/force.da...` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && tail -3 postProcessing/forces/0/force.dat 2>/dev/null\necho ---\nfind postProcessing -iname \"*.dat\" | xargs -I{} sh -c 'echo ==={}; tail -3 {}'\n"
}
```

**output**

```
exit_code: 0

960             8.0341733e-05 1.7497404e-03 9.5711510e-01 2.3353186e-04 1.6584155e-03 9.5859018e-01 -1.5319013e-04 9.1324929e-05 -1.4750741e-03
980             -1.2800287e-03 1.9436804e-03 9.5726138e-01 -1.0789807e-03 1.9518714e-03 9.5873659e-01 -2.0104806e-04 -8.1909256e-06 -1.4752107e-03
1000            -2.1773052e-03 1.4191429e-03 9.5727367e-01 -2.0026629e-03 1.5268249e-03 9.5874944e-01 -1.7464227e-04 -1.0768206e-04 -1.4757655e-03
---
===postProcessing/forces/0/force.dat
960             8.0341733e-05 1.7497404e-03 9.5711510e-01 2.3353186e-04 1.6584155e-03 9.5859018e-01 -1.5319013e-04 9.1324929e-05 -1.4750741e-03
980             -1.2800287e-03 1.9436804e-03 9.5726138e-01 -1.0789807e-03 1.9518714e-03 9.5873659e-01 -2.0104806e-04 -8.1909256e-06 -1.4752107e-03
1000            -2.1773052e-03 1.4191429e-03 9.5727367e-01 -2.0026629e-03 1.5268249e-03 9.5874944e-01 -1.7464227e-04 -1.0768206e-04 -1.4757655e-03
===postProcessing/forces/0/moment.dat
960             -1.5086727e-04 4.4112497e-05 -2.4773184e-02 -1.4962550e-04 4.3073660e-05 -2.3507814e-02 -1.2417680e-06 1.0388363e-06 -1.2653695e-03
980             -1.4455244e-04 2.0733666e-05 -2.4773971e-02 -1.4329959e-04 2.0010056e-05 -2.3508634e-02 -1.2528493e-06 7.2361002e-07 -1.2653371e-03
1000            -9.2879457e-05 -9.8482863e-06 -2.4774695e-02 -9.2048157e-05 -9.9855383e-06 -2.3509357e-02 -8.3129960e-07 1.3725198e-07
```

### agent

Force/moment history is stable over the last iterations. Fz ≈ 0.9573 N, Mz ≈ -0.02477 N·m.

### tool: bash

`python3 - <<'EOF'` exit 0

**input**

```
{
  "cmd": "python3 - <<'EOF'\nimport numpy as np\nD=0.254\nn=4014/60.0\nomega=n*2*np.pi\nrho=1.225\n\nT=0.9573   # N (Fz, average of last ~5 samples)\nMz=0.024775 # N*m magnitude (shaft torque)\nP=Mz*omega\n\nCT=T/(rho*n**2*D**4)\nCP=P/(rho*n**3*D**5)\n\nprint(\"n (rev/s)\", n)\nprint(\"omega (rad/s)\", omega)\nprint(\"T (N)\", T)\nprint(\"P (W)\", P)\nprint(\"CT\", CT)\nprint(\"CP\", CP)\nprint(\"eta (from CT,CP,J=0)\", \"n/a (static, J=0)\")\nEOF"
}
```

**output**

```
exit_code: 0

n (rev/s) 66.9
omega (rad/s) 420.34509705031434
T (N) 0.9573
P (W) 10.414049779421537
CT 0.04194931448506412
CP 0.026855709110827755
eta (from CT,CP,J=0) n/a (static, J=0)
```

### agent

Let's produce a results figure (pressure on the blade + velocity slice through the disk) and check residual convergence trend.

### tool: bash

`cd /work/20260716-234837-aa76/case && python3 - <<'EOF'` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && python3 - <<'EOF'\nimport numpy as np\ndata = np.loadtxt('postProcessing/forces/0/force.dat', comments='#')\nt = data[:,0]\nFz = data[:,3]\nprint(\"last 10 Fz:\", Fz[-10:])\nmdata = np.loadtxt('postProcessing/forces/0/moment.dat', comments='#')\nMz = mdata[:,3]\nprint(\"last 10 Mz:\", Mz[-10:])\nprint(\"mean Fz last 200 iters:\", Fz[t>800].mean(), \"std:\", Fz[t>800].std())\nprint(\"mean Mz last 200 iters:\", Mz[t>800].mean(), \"std:\", Mz[t>800].std())\nEOF"
}
```

**output**

```
exit_code: 0

last 10 Fz: [0.95687898 0.95687562 0.95703361 0.95721543 0.95724181 0.95712616
 0.95703415 0.9571151  0.95726138 0.95727367]
last 10 Mz: [-0.02477423 -0.0247751  -0.02477642 -0.02477763 -0.02477747 -0.02477567
 -0.02477371 -0.02477318 -0.02477397 -0.02477469]
mean Fz last 200 iters: 0.957105591 std: 0.00014077598392124636
mean Mz last 200 iters: -0.0247752073 std: 1.4744230091805084e-06
```

### agent

Very stable integrated forces over the last 200 iterations (std < 0.02%), even though field residuals plateaued around 1e-3 rather than hitting the 1e-5 target — that plateau is typical of MRF steady solutions with a mildly unsteady tip-vortex/wake region that a steady RANS frame cannot fully settle, but the integrated loads are clearly converged for this mesh. Let's reconstruct and render the field.

### tool: bash

`cd /work/20260716-234837-aa76/case && reconstructPar -latestTime > log.reconst...` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && reconstructPar -latestTime > log.reconstructPar 2>&1; tail -10 log.reconstructPar; ls"
}
```

**output**

```
exit_code: 0

No point fields

No lagrangian fields

No finite-area fields

End

0
0.orig
1000
case.foam
constant
log.blockMesh
log.checkMesh
log.decomposePar1
log.decomposePar2
log.decomposePar3
log.reconstructPar
log.reconstructParMesh
log.simpleFoam
log.snappyHexMesh
log.topoSet
postProcessing
processor0
processor1
processor2
processor3
system
```

### tool: bash

`cd /work/20260716-234837-aa76/case && python3 /work/.toolbox/render.py . --fie...` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && python3 /work/.toolbox/render.py . --fields U p --normal x --time 1000 --out /work/20260716-234837-aa76/renders/fields 2>&1 | tail -30"
}
```

**output**

```
exit_code: 0
[took 11s]

time 1000  (available: 0, 1000)
cells 38,270  points 43,236
```

### tool: bash

`ls /work/20260716-234837-aa76/renders/fields` exit 0

**input**

```
{
  "cmd": "ls /work/20260716-234837-aa76/renders/fields"
}
```

**output**

```
exit_code: 0

U_x_1000.png
mesh_x.png
p_x_1000.png
```

### tool: read_file

`/work/20260716-234837-aa76/renders/fields/U_x_1000.png`

**input**

```
{
  "path": "/work/20260716-234837-aa76/renders/fields/U_x_1000.png"
}
```

**output**

```
[image/png, 54504 bytes]
/work/20260716-234837-aa76/renders/fields/U_x_1000.png — 1100x800 image/png, 54503 bytes
```

### agent

This looks exactly right physically — a classic hover slipstream: quiescent far field, air drawn in from above/around the disk, accelerated through the rotor into a contracting jet below, consistent with a downward-thrusting (here +z... wait let's confirm direction) prop pushing air one way and generating reaction thrust the other way. Let's check the pressure slice too.

### tool: read_file

`/work/20260716-234837-aa76/renders/fields/p_x_1000.png`

**input**

```
{
  "path": "/work/20260716-234837-aa76/renders/fields/p_x_1000.png"
}
```

**output**

```
[image/png, 16530 bytes]
/work/20260716-234837-aa76/renders/fields/p_x_1000.png — 1100x800 image/png, 16528 bytes
```

### agent

Let's quantify the near-wall resolution (y+) to substantiate what the mesh can and can't be trusted for.

### tool: bash

`cd /work/20260716-234837-aa76/case && postProcess -func yPlus -latestTime > lo...` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && postProcess -func yPlus -latestTime > log.yPlus 2>&1; tail -30 log.yPlus"
}
```

**output**

```
exit_code: 0

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 = 1000

Time = 1000

Reading fields:

Executing functionObjects
--> FOAM Warning : 
    From virtual bool Foam::functionObjects::yPlus::execute()
    in file yPlus/yPlus.C at line 173
    Unable to find turbulence model in the database: yPlus will not be calculated
--> FOAM Warning : 
    From virtual bool Foam::functionObjects::yPlus::execute()
    in file yPlus/yPlus.C at line 179
    Please try to use the solver option -postProcess, e.g.: <solver> -postProcess -func yPlus
yPlus yPlus write:
    writing field yPlus
    patch propeller y+ : min = 0, max = 0, average = 0

End
```

### tool: bash

`cd /work/20260716-234837-aa76/case && simpleFoam -postProcess -func yPlus -lat...` exit 0

**input**

```
{
  "cmd": "cd /work/20260716-234837-aa76/case && simpleFoam -postProcess -func yPlus -latestTime > log.yPlus2 2>&1; tail -15 log.yPlus2"
}
```

**output**

```
exit_code: 0

    F3              false;
    decayControl    false;
    kInf            0;
    omegaInf        0;
}

Creating MRF zone list from MRFProperties
    creating MRF zone: MRF1
No finite volume options present
yPlus yPlus write:
    writing field yPlus
    patch propeller y+ : min = 31.91253, max = 370.257, average = 177.7506

End
```

### tool: write_file

`/work/20260716-234837-aa76/QUICKLOOK_SUMMARY.md`

**input**

```
{
  "path": "/work/20260716-234837-aa76/QUICKLOOK_SUMMARY.md",
  "content": "# APC Slow Flyer 10x4.7 — static thrust quick look\n\n## What was run\n- Geometry: `/work/geometry/apc_sf_10x4.7_propeller.stl`, D = 0.254 m, 2 blades, checked\n  clean (0 open/non-manifold edges, enclosed volume, single closed surface per blade+hub).\n  Rotation axis identified as **z** (rotor disk lies in the x-y plane).\n- Mesh: snappyHexMesh, background box 1.6 m cube (~6.3 D each way from the rotor),\n  distance-based + surface refinement around the blade to level 3 (~6.25 mm cells),\n  a cylindrical refinement region (R=0.16 m, |z|<0.03 m) around the disk to level 2.\n  **38,270 cells total, no boundary-layer inflation layers** (wall functions on\n  unresolved near-wall cells — see caveats). checkMesh: max non-orthogonality 44.9°,\n  2 highly skewed faces, 688 concave cells out of 38,270 (~1.8%) — localize...
```

**output**

```
wrote 7605 bytes to /work/20260716-234837-aa76/QUICKLOOK_SUMMARY.md
```

### tool: fetch

`paths=['/work/20260716-234837-aa76/QUICKLOOK_SUMMARY.md', '/work/20260829-2348...`

**input**

```
{
  "paths": [
    "/work/20260716-234837-aa76/QUICKLOOK_SUMMARY.md",
    "/work/20260716-234837-aa76/renders/geom/geometry.png",
    "/work/20260716-234837-aa76/renders/mesh/mesh_x.png",
    "/work/20260716-234837-aa76/renders/mesh/mesh_y.png",
    "/work/20260716-234837-aa76/renders/mesh/mesh_z.png",
    "/work/20260716-234837-aa76/renders/fields/U_x_1000.png",
    "/work/20260716-234837-aa76/renders/fields/p_x_1000.png"
  ]
}
```

**output**

```
copied 7 file(s) to the user's machine:
  C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260716-234837-aa76\files\20260716-234837-aa76\QUICKLOOK_SUMMARY.md
  C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260716-234837-aa76\files\20260716-234837-aa76\renders\geom\geometry.png
  C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260716-234837-aa76\files\20260716-234837-aa76\renders\mesh\mesh_x.png
  C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260716-234837-aa76\files\20260716-234837-aa76\renders\mesh\mesh_y.png
  C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260716-234837-aa76\files\20260716-234837-aa76\renders\mesh\mesh_z.png
  C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260716-234837-aa76\files\20260716-234837-aa76\renders\fields\U_x_1000.png
  C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260716-234837-aa76\files\20260716-234837-aa76\renders\fields\p_x_1000.png
```

### agent

## Summary

**Geometry & mesh checked before solving:** the STL is clean (0 open/non-manifold edges, correct 0.254 m diameter), rotation axis is z. Mesh is a snappyHexMesh cut with distance+surface refinement around the blade (~6.25 mm cells at finest level) and a cylindrical MRF refinement zone, 38,270 cells total, no boundary-layer inflation layers. `checkMesh` passes topology but flags 688 mildly concave cells and 2 highly skewed faces at the snapped blade surface — not blocking, but a real coarseness signal. Renders of geometry and mesh cuts are in `renders/`.

**Rotation handling:** MRF (steady, single rotating reference frame), not a sliding mesh. The rotating `cellZone` is a cylinder on axis z through the origin, radius 0.16 m (≈1.26×R_tip), |z| ≤ 0.03 m — built with `topoSet`/`cylinderToCell`, same footprint as the mesh's own level-2 refinement region. The blade wall is an ordinary stationary no-slip wall; MRF adds the frame source terms inside that zone only.

**Static condition:** zero freestream, `pressureInletOutletVelocity`/`totalPressure(p0=0)` on the far box. (Note: I first tried the more usual `freestreamVelocity`/`freestreamPressure` pair and it crashed with a floating-point exception — that BC normalizes by the freestream speed to get a flow direction, which is a division by zero when the freestream is exactly zero. Switched to the pressure-driven entrainment pair instead, which is the right choice for a true static/hover case.)

**Headline numbers** (n = 66.9 rev/s, ω = 420.35 rad/s):
- Thrust T ≈ **0.957 N**
- Shaft torque Q ≈ 0.0248 N·m → Shaft power P ≈ **10.4 W**
- **C_T ≈ 0.042, C_P ≈ 0.027** (n in rev/s, so no stray 2π factor)
- Integrated forces are flat to ~0.02% over the last 200 iterations even though field residuals plateaued at ~1e-3, not 1e-5 — I'm treating that as converged-enough for a quick look.

**Important caveat:** y+ on the blade averages ~178 (range 32–370) with no inflation layers and only ~4-6 cells across the chord. That's a genuinely coarse near-wall/surface resolution, and it's very likely biasing C_T low and the derived figure of merit (≈0.23, vs. ~0.6–0.7 typical for props this size) — so please treat these numbers as order-of-magnitude, not something to hold against the UIUC tunnel data yet. Full reasoning and the flow-field figure (slipstream through the disk, physically sensible) are in `QUICKLOOK_SUMMARY.md`.

**What a fuller study needs**, roughly in priority order: (1) a real mesh-refinement family with boundary-layer inflation layers (~15–100× more cells) to get a grid-converged C_T/C_P — this is the big one; (2) a domain-size check; (3) consideration of low-Re transition effects (tip Re≈9×10⁴); (4) an MRF-vs-transient (AMI sliding mesh) check since static thrust is the case where steady MRF is most likely to be biased. That's roughly a half-day to a day of compute on more cores than the 4 used here — I haven't started any of it, flagging it for your call before spending that.

## 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.