--- title: "Four numbers, four published bands, one animation" url: "https://tryreynolds.com/studies/vortex-shedding-cylinder" description: "The cylinder wake at Re = 100 is the most measured flow in fluid dynamics, which makes it the least forgiving thing to run. Reynolds hit every quantity it was asked for, inside the published range, and drew the wake while it did." --- **[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/vortex-shedding-cylinder. It lives at https://tryreynolds.com/studies/vortex-shedding-cylinder.md, and [tryreynolds.com/llms.txt](https://tryreynolds.com/llms.txt) indexes every one of them. # Four numbers, four published bands, one animation The cylinder wake at Re = 100 is the most measured flow in fluid dynamics, which makes it the least forgiving thing to run. Reynolds hit every quantity it was asked for, inside the published range, and drew the wake while it did. RUN 01VALIDATIONUNSTEADY WAKESFEBRUARY 202620260211-232328-2ade - **Asked**: “Simulate airflow past a 2D cylinder.” Then: the Strouhal number and mean drag coefficient, to check against published values. - **Run**: pimpleFoam, transient, laminar · 110,000 cells · 8 cores · 35 minutes - **Result**: St = 0.1653, four of four metrics inside the published bands - **Strouhal number**: 0.1653 against a published 0.164 to 0.167, inside - **Mean drag**: C_d = 1.345 against 1.32 to 1.37, inside - **Drag amplitude**: 0.0109 against 0.009 to 0.011, inside - **Lift amplitude**: ±0.339 against ±0.32 to 0.34, inside - **Physical time**: 12.5 s, about 20 shedding periods ![Animated vortex street behind a cylinder at Re = 100](https://tryreynolds.com/assets/cyl-shedding-poster-BYjqF6XY.webp) Figure 1 Counter-rotating vortices shedding alternately from each side, convecting downstream as a von Kármán street. ## The wake, as it ran Below a Reynolds number of about 47 the wake behind a cylinder is two steady standing eddies. Above it, the wake becomes unstable and starts shedding vortices alternately from each side, at a frequency so reliable that it is used to measure flow speed in commercial flowmeters. At Re = 100 the shedding is fully developed, perfectly periodic, and genuinely two-dimensional, which is why every solver in the world is pointed at it sooner or later. ## Getting there deliberately A perfectly symmetric mesh has a problem: the physical instability that produces shedding needs an asymmetry to grow from, and in exact arithmetic there is none. Real solvers eventually break symmetry through rounding error, which can take an enormous amount of simulated time. Reynolds handled it the way an experimentalist would, by nudging the flow: it held the inlet at five degrees of incidence for the first second to trip the instability, then released it and let the wake develop on its own. That is a standard technique, and choosing it is the difference between a run that sheds in twelve seconds and one that is still deciding after several hours of compute. The mesh was built for the question. An O-grid around the cylinder, with cells held below 0.07 diameters all the way out to eight diameters of radius, so that vortices survive being convected downstream instead of dissolving into numerical diffusion a few diameters back. 110,000 cells, adaptive time stepping at a maximum Courant number of 0.9, 12.5 seconds of physical time on eight cores in about 35 minutes. ## The measurement Strouhal number came from interpolated zero crossings of the lift coefficient over the last five seconds, giving a shedding period of 0.60480 ± 0.00008 s. That is a deliberate choice over the more obvious route: a Fourier transform of a record this short resolves frequency far too coarsely to quote four figures, and zero crossings do not care how long the record is. Four independent quantities, four published bands, four hits. Getting the Strouhal number right is common. Getting the Strouhal number, the mean drag, the drag fluctuation and the lift fluctuation right at the same time means the wake is not merely oscillating at roughly the right rate, it is exerting the right forces on the body while it does so. The run wrote 149 frames of spanwise vorticity across five shedding cycles, so the wake can be watched rather than inferred. ![The O-grid mesh around the cylinder, dense at the surface and holding resolution into the wake](https://tryreynolds.com/assets/cyl-mesh-UFSiYGb0.png) Figure 2 The O-grid: dense at the surface, holding resolution downstream into the wake. ![Time histories of lift and drag coefficient settling into a periodic limit cycle](https://tryreynolds.com/assets/cyl-transient-CFO_Jcsl.png) Figure 3 The instability growing, saturating, and settling into a periodic limit cycle. ![Computed Strouhal number, mean drag, drag amplitude and lift amplitude against published ranges](https://tryreynolds.com/assets/cyl-results-D11xGR_2.png) Figure 4 Four quantities against their published bands. Four of four inside. ## 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. 24 messages, 106 tool calls ### you Can you simulate airflow past a 2D cylinder, meaning steady flow past a cylinder in two dimensions? ### agent I'll set this up. First, a quick look at the workspace and toolbox. ### tool: bash `ls /work/.toolbox/ /work/.toolbox/notes/ 2>&1; echo ---; ls /work | head -40` exit 0 **input** ``` { "cmd": "ls /work/.toolbox/ /work/.toolbox/notes/ 2>&1; echo ---; ls /work | head -40" } ``` **output** ``` exit_code: 0 /work/.toolbox/: README.md cells_estimate.py geometry_view.py log_digest.py mesh_digest.py notes render.py /work/.toolbox/notes/: bundle-layout.md openfoam-agent-architecture.md openfoam-field-notes.md --- 20260210-112913-259e 20260210-114429-04e6 20260210-121326-8584 20260210-132602-c3a9 20260210-133309-9076 20260210-135827-9e03 20260211-144909-2d77 20260211-205828-a875 20260211-232328-2ade bend bend80 contraction duct-bend duct-bend-loss-note.md duct100-eod duct80-2026 duct_bend elbow elbow80 expansion geotest lduct-100mm mitre-bend-pressure-drop.md mitre80-8ms notes results.json yduct yduct-split-2026 yduct70 ysplit-2026-08-24 ysplit-8ms ysplit-9ms ``` ### tool: bash `ls $FOAM_TUTORIALS/incompressible/simpleFoam/ ; echo ---; ls $FOAM_TUTORIALS/i...` exit 0 **input** ``` { "cmd": "ls $FOAM_TUTORIALS/incompressible/simpleFoam/ ; echo ---; ls $FOAM_TUTORIALS/incompressible/pimpleFoam/laminar/ 2>/dev/null" } ``` **output** ``` exit_code: 0 T3A airFoil2D backwardFacingStep2D bump2D mixerVessel2D motorBike pipeCyclic pitzDaily pitzDailyExptInlet pitzDaily_fused rotatingCylinders rotorDisk simpleCar squareBend turbineSiting turbulentFlatPlate windAroundBuildings --- contactAngleCavity contaminatedDroplet2D cylinder2D filmPanel0 inclinedPlaneFilm mixerVesselAMI2D movingCone planarContraction planarPoiseuille sloshing2D ``` ### tool: bash `wc -l /work/.toolbox/notes/*.md /work/.toolbox/README.md; echo ---; head -120 ...` exit 0 **input** ``` { "cmd": "wc -l /work/.toolbox/notes/*.md /work/.toolbox/README.md; echo ---; head -120 /work/.toolbox/notes/openfoam-field-notes.md" } ``` **output** ``` exit_code: 0 33 /work/.toolbox/notes/bundle-layout.md 1083 /work/.toolbox/notes/openfoam-agent-architecture.md 235 /work/.toolbox/notes/openfoam-field-notes.md 24 /work/.toolbox/README.md 1375 total --- # OpenFOAM field notes Distilled from a longer architecture document (`openfoam-agent-architecture.md`, in this directory). These are observations, not a procedure — nothing here is a step you owe anyone. --- ## The cost asymmetry Mistakes are cheap while you are authoring files and expensive once you have committed compute to them. | What you are about to do | What a mistake costs | |---|---| | Write a dictionary | seconds | | `snappyHexMesh` build | 20 minutes to hours | | Production solve | hours to days | | Report a wrong number | the whole study | Everything below is a consequence of that table. The cheapest checks — `foamDictionary` parsing a file, `foamToC` telling you what this build actually compiled in, a one-iteration solver probe on a trivial mesh, an arithmetic cell-count estimate — cost less than a minute and sit directly upstream of the expensive things. ## Verifying against the installation rather than from memory There is no complete static grammar for OpenFOAM dictionaries. It is distributed across the C++ classes that consume each dict, differs by fork and version, and grows with every compiled library. The g ``` ### agent Plan: an O-grid `blockMesh` around the cylinder, laminar `simpleFoam` (steady) — and I'll validate drag against published benchmarks. Building the mesh generator now. ### tool: write_file `/work/20260211-232328-2ade/tools/make_mesh.py` **input** ``` { "path": "/work/20260211-232328-2ade/tools/make_mesh.py", "content": "#!/usr/bin/env python3\n\"\"\"Generate an O-grid blockMeshDict for 2D flow past a circular cylinder.\n\nDomain: annulus from cylinder radius Ri to far-field radius Ro, 8 sectors of 45 deg.\nFar field split into inlet (upstream half) and outlet (downstream half).\nFlow is in +x. One cell in z, front/back are 'empty'.\n\"\"\"\nimport math, sys, argparse\n\nap = argparse.ArgumentParser()\nap.add_argument('--D', type=float, default=0.1) # cylinder diameter [m]\nap.add_argument('--Ro', type=float, default=40.0) # far-field radius in diameters\nap.add_argument('--nr', type=int, default=140) # radial cells\nap.add_argument('--nc', type=int, default=32) # circumferential cells per 45deg sector\nap.add_argument('--d1', type=float, default=None) # first cell height [m]; default D/125\nap.add_argumen... ``` **output** ``` wrote 4309 bytes to /work/20260211-232328-2ade/tools/make_mesh.py ``` ### tool: bash `cd /work/20260211-232328-2ade && mkdir -p cyl_Re40/{system,constant,0} && cd c...` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && mkdir -p cyl_Re40/{system,constant,0} && cd cyl_Re40 && python3 ../tools/make_mesh.py --out system/blockMeshDict" } ``` **output** ``` exit_code: 0 Ri=0.05 Ro=4.0 first cell dr=8.000e-04 last dr=1.460e-01 expansion/cell=1.03817 grading=182.49 surface arc length ds=1.227e-03 (dr/ds at wall = 0.65) cells = 35840 wrote system/blockMeshDict ``` ### tool: bash `cat $FOAM_TUTORIALS/incompressible/simpleFoam/airFoil2D/system/forceCoeffs 2>/...` exit 0 **input** ``` { "cmd": "cat $FOAM_TUTORIALS/incompressible/simpleFoam/airFoil2D/system/forceCoeffs 2>/dev/null || find $FOAM_TUTORIALS -name \"*forceCoeff*\" | head; echo ---; ls $FOAM_TUTORIALS/incompressible/simpleFoam/airFoil2D/system $FOAM_TUTORIALS/incompressible/simpleFoam/airFoil2D/constant" } ``` **output** ``` exit_code: 0 /usr/lib/openfoam/openfoam2512/tutorials/incompressible/pimpleFoam/LES/NACA4412/system/forceCoeffs /usr/lib/openfoam/openfoam2512/tutorials/incompressible/pisoFoam/LES/motorBike/motorBike/system/forceCoeffs /usr/lib/openfoam/openfoam2512/tutorials/incompressible/simpleFoam/motorBike/system/forceCoeffs /usr/lib/openfoam/openfoam2512/tutorials/incompressible/simpleFoam/simpleCar/system/forceCoeffs --- /usr/lib/openfoam/openfoam2512/tutorials/incompressible/simpleFoam/airFoil2D/constant: polyMesh.orig transportProperties turbulenceProperties /usr/lib/openfoam/openfoam2512/tutorials/incompressible/simpleFoam/airFoil2D/system: controlDict decomposeParDict fvSchemes fvSolution ``` ### tool: bash `cat $FOAM_TUTORIALS/incompressible/simpleFoam/simpleCar/system/forceCoeffs; ec...` exit 0 **input** ``` { "cmd": "cat $FOAM_TUTORIALS/incompressible/simpleFoam/simpleCar/system/forceCoeffs; echo ===; cat $FOAM_TUTORIALS/incompressible/simpleFoam/airFoil2D/system/fvSolution; echo ===; cat $FOAM_TUTORIALS/incompressible/simpleFoam/airFoil2D/system/fvSchemes" } ``` **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 | | \*---------------------------------------------------------------------------*/ forceCoeffs1 { type forceCoeffs; libs (forces); writeControl writeTime; writeFields true; patches (body); p p; U U; rho rhoInf; // Indicates incompressible log true; rhoInf 1; // Required when rho = rhoInf liftDir (0 1 0); dragDir (1 0 0); CofR (3.5 0 0); // Axle midpoint on ground pitchAxis (0 0 1); magUInf 10; lRef 4; // Wheelbase length Aref 1; // Estimated porosity on; } binField1 { type binField; libs (fieldFunctionObjects); binModel singleDirectionUniformBin; fields ``` ### tool: bash `cd /work/20260211-232328-2ade/cyl_Re40 && cat > 0/U <<'EOF'` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade/cyl_Re40 && cat > 0/U <<'EOF'\nFoamFile { version 2.0; format ascii; class volVectorField; object U; }\ndimensions [0 1 -1 0 0 0 0];\ninternalField uniform (1 0 0);\nboundaryField\n{\n inlet { type fixedValue; value uniform (1 0 0); }\n outlet { type inletOutlet; inletValue uniform (0 0 0); value uniform (1 0 0); }\n cylinder { type noSlip; }\n \"(front|back)\" { type empty; }\n}\nEOF\ncat > 0/p <<'EOF'\nFoamFile { version 2.0; format ascii; class volScalarField; object p; }\ndimensions [0 2 -2 0 0 0 0];\ninternalField uniform 0;\nboundaryField\n{\n inlet { type zeroGradient; }\n outlet { type fixedValue; value uniform 0; }\n cylinder { type zeroGradient; }\n \"(front|back)\" { type empty; }\n}\nEOF\ncat > constant/transportProperties <<'EOF'\nFoamFile { version 2.0; format ascii; class dictionary;... ``` **output** ``` exit_code: 0 j : 0.0012271538 .. 0.0012271538 k : 0.1 .. 0.1 No patch pairs to merge Writing polyMesh with 0 cellZones ---------------- Mesh Information ---------------- boundingBox: (-4 -4 0) (4 4 0.1) nPoints: 72192 nCells: 35840 nFaces: 143616 nInternalFaces: 71424 ---------------- Patches ---------------- patch 0 (start: 71424 size: 128) name: inlet patch 1 (start: 71552 size: 128) name: outlet patch 2 (start: 71680 size: 256) name: cylinder patch 3 (start: 71936 size: 35840) name: back patch 4 (start: 107776 size: 35840) name: front End ``` ### tool: bash `cd /work/20260211-232328-2ade/cyl_Re40 && checkMesh 2>&1 | tail -30` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade/cyl_Re40 && checkMesh 2>&1 | tail -30" } ``` **output** ``` exit_code: 0 Checking faceZone topology for multiply connected surfaces... No faceZones found. Checking basic cellZone addressing... No cellZones found. Checking basic pointZone addressing... No pointZones found. Checking geometry... Overall domain bounding box (-4 -4 0) (4 4 0.1) Mesh has 2 geometric (non-empty/wedge) directions (1 1 0) Mesh has 2 solution (non-empty) directions (1 1 0) All edges aligned with or perpendicular to non-empty directions. Boundary openness (3.4509367e-18 1.5729323e-19 -1.8691957e-15) OK. Max cell openness = 2.2228021e-16 OK. Max aspect ratio = 1.5295775 OK. Minimum face area = 9.8950098e-07. Maximum face area = 0.01459942. Face area magnitudes OK. Min volume = 9.8950098e-08. Max volume = 0.0014069969. Total volume = 5.0252583. Cell volumes OK. Mesh non-orthogonality Max: 1.9090959e-06 average: 0 Non-orthogonality check OK. Face pyramids OK. Max skewness = 0.016329353 OK. Coupled point location match (average 0) OK. Mesh OK. End ``` ### agent Mesh is clean (max non-orthogonality ~0, skewness 0.016, aspect ratio 1.53). Running Re=40 now. ### tool: bash `cd /work/20260211-232328-2ade/cyl_Re40 && (time simpleFoam > log.simpleFoam 2>...` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade/cyl_Re40 && (time simpleFoam > log.simpleFoam 2>&1); tail -20 log.simpleFoam; echo ---; grep -c \"^Time = \" log.simpleFoam" } ``` **output** ``` exit_code: 0 [took 97s] real 1m30.195s user 1m25.690s sys 0m1.670s smoothSolver: Solving for Ux, Initial residual = 3.0342097e-08, Final residual = 1.3831899e-10, No Iterations 4 smoothSolver: Solving for Uy, Initial residual = 1.0027028e-07, Final residual = 4.0723519e-10, No Iterations 4 GAMG: Solving for p, Initial residual = 1.7796005e-08, Final residual = 8.8285266e-10, No Iterations 3 time step continuity errors : sum local = 1.5742524e-11, global = -1.0161323e-12, cumulative = -3.5000103e-07 ExecutionTime = 86.91 s ClockTime = 90 s Time = 1965 smoothSolver: Solving for Ux, Initial residual = 3.0176297e-08, Final residual = 1.3756473e-10, No Iterations 4 smoothSolver: Solving for Uy, Initial residual = 9.9721485e-08, Final residual = 4.0501127e-10, No Iterations 4 GAMG: Solving for p, Initial residual = 1.770541e-08, Final residual = 8.7922507e-10, No Iterations 3 time step continuity errors : sum local = 1.5677823e-11, global = -1.0154012e-12, cumulative = -3.5000205e-07 ExecutionTime = 86.94 s ClockTime = 90 s SIMPLE solution converged in 1965 iterations End --- 1965 ``` ### tool: bash `cd /work/20260211-232328-2ade/cyl_Re40 && ls postProcessing/forceCoeffs1/0/ &&...` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade/cyl_Re40 && ls postProcessing/forceCoeffs1/0/ && head -15 postProcessing/forceCoeffs1/0/coefficient.dat && tail -2 postProcessing/forceCoeffs1/0/coefficient.dat" } ``` **output** ``` exit_code: 0 coefficient.dat # Force and moment coefficients # dragDir : (1.00000000e+00 0.00000000e+00 0.00000000e+00) # sideDir : (0.00000000e+00 0.00000000e+00 -1.00000000e+00) # liftDir : (0.00000000e+00 1.00000000e+00 0.00000000e+00) # rollAxis : (1.00000000e+00 0.00000000e+00 0.00000000e+00) # pitchAxis : (0.00000000e+00 0.00000000e+00 -1.00000000e+00) # yawAxis : (0.00000000e+00 1.00000000e+00 0.00000000e+00) # magUInf : 1.00000000e+00 # lRef : 1.00000000e-01 # Aref : 1.00000000e-02 # CofR : (0.00000000e+00 0.00000000e+00 0.00000000e+00) # # Time Cd Cd(f) Cd(r) Cl Cl(f) Cl(r) CmPitch CmRoll CmYaw Cs Cs(f) Cs(r) 1 2.85280699e+02 1.42631727e+02 1.42648973e+02 1.72459498e-02 8.70788440e-03 8.53806536e-03 8.49095198e-05 -8.62297488e-03 1.42640350e+02 1.55951061e-20 1.42640350e+02 -1.42640350e+02 2 1.90008674e+02 9.50018528e+01 9.50068207e+01 4.96783573e-03 2.78827571e-03 2.17956002e-03 3.04357842e-04 -2.48391786e-03 9.50043368e+01 1.54902404e-20 9.50043368e+01 -9.50043368e+01 1964 1.51918654e+00 7.59593280e-01 7.59593265e-01 -1.46615000e-08 -9.86783862e-09 -4.79366136e-09 -2.53708863e-09 7.33074992e-09 7.59593272e-01 1.627 ``` ### agent Cd = 1.519 at Re = 40 (literature: 1.50–1.56). Let me add a second Re and check grid/domain sensitivity, running them in parallel. ### tool: write_file `/work/20260211-232328-2ade/tools/clone_case.sh` **input** ``` { "path": "/work/20260211-232328-2ade/tools/clone_case.sh", "content": "#!/bin/bash\n# clone_case.sh [mesh args...]\nset -e\ncd \"$(dirname \"$0\")/..\"\nNEW=$1; NU=$2; shift 2\nrm -rf \"$NEW\"; mkdir -p \"$NEW\"\ncp -r cyl_Re40/{system,constant,0} \"$NEW\"/\nrm -f \"$NEW\"/system/blockMeshDict\nsed -i \"s/^nu .*/nu [0 2 -1 0 0 0 0] $NU;/\" \"$NEW\"/constant/transportProperties\n(cd \"$NEW\" && python3 ../tools/make_mesh.py --out system/blockMeshDict \"$@\" > log.mesh 2>&1 && blockMesh > log.blockMesh 2>&1)\necho \"$NEW ready: $(grep -h 'cells =' \"$NEW\"/log.mesh)\"\n" } ``` **output** ``` wrote 495 bytes to /work/20260211-232328-2ade/tools/clone_case.sh ``` ### tool: bash `cd /work/20260211-232328-2ade && chmod +x tools/clone_case.sh &&` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && chmod +x tools/clone_case.sh &&\ntools/clone_case.sh cyl_Re20 5.0e-3 &&\ntools/clone_case.sh cyl_Re40_fine 2.5e-3 --nr 200 --nc 48 --d1 0.0004 &&\ntools/clone_case.sh cyl_Re40_far 2.5e-3 --Ro 80 --nr 165 &&\ntools/clone_case.sh cyl_Re40_coarse 2.5e-3 --nr 90 --nc 20 --d1 0.0016" } ``` **output** ``` exit_code: 0 cyl_Re20 ready: cells = 35840 cyl_Re40_fine ready: cells = 76800 cyl_Re40_far ready: cells = 42240 cyl_Re40_coarse ready: cells = 14400 ``` ### tool: job_start `for c in cyl_Re20 cyl_Re40_fine cyl_Re40_far cyl_Re40_coarse; do (cd $c && sim...` **input** ``` { "cmd": "for c in cyl_Re20 cyl_Re40_fine cyl_Re40_far cyl_Re40_coarse; do (cd $c && simpleFoam > log.simpleFoam 2>&1; echo \"$c done rc=$?\") & done; wait", "cwd": "/work/20260211-232328-2ade", "name": "sweep1" } ``` **output** ``` started job 00832411-7f80-4123-9049-d702f51142a9 (sweep1) ``` ### tool: write_file `/work/20260211-232328-2ade/tools/post.py` **input** ``` { "path": "/work/20260211-232328-2ade/tools/post.py", "content": "#!/usr/bin/env python3\n\"\"\"Post-process a cylinder case: Cd, wake length, separation angle, Cp distribution.\"\"\"\nimport sys, os, math, json\nimport numpy as np\nimport pyvista as pv\npv.OFF_SCREEN = True\n\ncase = sys.argv[1]\nD = 0.1; R = D/2; Uinf = 1.0\n\n# --- force coefficients (last line) ---\ncf = None\nfor root, _, files in os.walk(os.path.join(case, 'postProcessing/forceCoeffs1')):\n for f in files:\n if f == 'coefficient.dat': cf = os.path.join(root, f)\nrows = [l.split() for l in open(cf) if not l.startswith('#')]\nCd = float(rows[-1][1]); Cl = float(rows[-1][4]); Cdf = float(rows[-1][2])\n\nfoam = os.path.join(case, 'case.foam'); open(foam, 'w').close()\nrd = pv.OpenFOAMReader(foam)\nrd.set_active_time_value(rd.time_values[-1])\nrd.enable_all_cell_arrays()\nmesh = rd.read()\nblk = mesh[0] if... ``` **output** ``` wrote 2535 bytes to /work/20260211-232328-2ade/tools/post.py ``` ### tool: bash `cd /work/20260211-232328-2ade && python3 tools/post.py cyl_Re40 2>&1 | tail -2...` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && python3 tools/post.py cyl_Re40 2>&1 | tail -20" } ``` **output** ``` exit_code: 0 { "case": "cyl_Re40", "Cd": 1.51918647, "Cd_visc": NaN, "Cl": -1.45169444e-08, "Lw_over_D": 2.23933148908675, "theta_sep_deg": 53.31844841026258, "Cp_base": 1.158689022064209, "Cp_stag": -0.4788307845592499, "ncells": 35840 } ``` ### tool: bash `cd /work/20260211-232328-2ade && sed -i 's/cp_base = float(cp\[-1\]); cp_front...` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && sed -i 's/cp_base = float(cp\\[-1\\]); cp_front = float(cp\\[0\\])/cp_base = float(cp[0]); cp_front = float(cp[-1])/' tools/post.py && grep -n cp_base tools/post.py" } ``` **output** ``` exit_code: 0 55:cp_base = float(cp[0]); cp_front = float(cp[-1]) 59: Cp_base=cp_base, Cp_stag=cp_front, ncells=int(blk.n_cells)) ``` ### tool: job_check `job_id=00832411-7f80-4123-9049-d702f51142a9` **input** ``` { "job_id": "00832411-7f80-4123-9049-d702f51142a9" } ``` **output** ``` job 00832411-7f80-4123-9049-d702f51142a9 name=sweep1 status=running log_size=26 running_for=1.1min log: bytes 0–26, eof=True cyl_Re40_coarse done rc=0 ``` ### tool: write_file `/work/20260211-232328-2ade/tools/render.py` **input** ``` { "path": "/work/20260211-232328-2ade/tools/render.py", "content": "#!/usr/bin/env python3\n\"\"\"Render velocity magnitude + streamlines and pressure for a cylinder case.\"\"\"\nimport sys, os\nimport numpy as np\nimport pyvista as pv\npv.OFF_SCREEN = True\n\ncase = sys.argv[1]\ntag = os.path.basename(case)\nD = 0.1; R = D/2\nxmin, xmax, ymin, ymax = -3*D, 8*D, -3*D, 3*D\n\nfoam = os.path.join(case, 'case.foam'); open(foam, 'w').close()\nrd = pv.OpenFOAMReader(foam); rd.set_active_time_value(rd.time_values[-1])\nrd.enable_all_cell_arrays()\nblk = rd.read()[0]\ncc = blk.cell_data_to_point_data()\ncc['Umag'] = np.linalg.norm(cc['U'], axis=1)\n\nslc = cc.slice(normal='z', origin=(0, 0, 0.05))\nclip = slc.clip_box([xmin, xmax, ymin, ymax, -1, 1], invert=False)\n\n# seed streamlines on a vertical line upstream\nseed = pv.LineSource((xmin*0.98, ymin*0.98, 0.05), (xmin*0.98, ymax*0.98, 0.0... ``` **output** ``` wrote 2647 bytes to /work/20260211-232328-2ade/tools/render.py ``` ### tool: job_check `job_id=00832411-7f80-4123-9049-d702f51142a9` **input** ``` { "job_id": "00832411-7f80-4123-9049-d702f51142a9" } ``` **output** ``` job 00832411-7f80-4123-9049-d702f51142a9 name=sweep1 status=running log_size=26 running_for=1.6min log: bytes 26–26, eof=True ``` ### tool: bash `cd /work/20260211-232328-2ade && python3 tools/render.py cyl_Re40 2>&1 | tail ...` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && python3 tools/render.py cyl_Re40 2>&1 | tail -5" } ``` **output** ``` exit_code: 0 color='white' color='w' color=[1.0, 1.0, 1.0] color=[255, 255, 255] color='#FFFFFF' ``` ### tool: bash `cd /work/20260211-232328-2ade && python3 tools/render.py cyl_Re40 2>&1 | head ...` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && python3 tools/render.py cyl_Re40 2>&1 | head -30" } ``` **output** ``` exit_code: 0 Traceback (most recent call last): File "/usr/local/lib/python3.12/dist-packages/pyvista/plotting/colors.py", line 1761, in __init__ self._from_str(color) File "/usr/local/lib/python3.12/dist-packages/pyvista/plotting/colors.py", line 1925, in _from_str raise ValueError(msg) from None ValueError: Invalid color name or hex string: 0.25 The above exception was the direct cause of the following exception: Traceback (most recent call last): File "/__modal/volumes/vo-T9FaBsi3H3bYZMAzJFmtee/20260211-232328-2ade/tools/render.py", line 39, in pl.add_mesh(circ, color='0.25') File "/usr/local/lib/python3.12/dist-packages/pyvista/_deprecate_positional_args.py", line 243, in inner_f return f(*args, **kwargs) ^^^^^^^^^^^^^^^^^^ File "/usr/local/lib/python3.12/dist-packages/pyvista/plotting/plotter.py", line 4212, in add_mesh prop = Property(**prop_kwargs) ^^^^^^^^^^^^^^^^^^^^^^^ File "/usr/local/lib/python3.12/dist-packages/pyvista/core/utilities/misc.py", line 442, in __call__ obj = super().__call__(*args, **kwargs) # type: ignore[misc] ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/usr/local/lib/python3.12/dist-packages/pyvista/_deprecate_positional_args.py", line 243, in inner_f return f(*args, **kwargs) ^^^^^^^^^^^^^^^^^^ File "/usr/local/lib/python3.12/dist-packages/pyvista/plotti ``` ### tool: bash `cd /work/20260211-232328-2ade && sed -i "s/color='0.25'/color='dimgray'/" tool...` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && sed -i \"s/color='0.25'/color='dimgray'/\" tools/render.py && python3 tools/render.py cyl_Re40 2>&1 | tail -5" } ``` **output** ``` exit_code: 0 ``` ### tool: bash `cd /work/20260211-232328-2ade && python3 tools/render.py cyl_Re40 2>&1 | head ...` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && python3 tools/render.py cyl_Re40 2>&1 | head -20; ls cyl_Re40/*.png" } ``` **output** ``` exit_code: 0 cyl_Re40/cyl_Re40_U.png cyl_Re40/cyl_Re40_mesh.png cyl_Re40/cyl_Re40_p.png ``` ### tool: read_file `/work/20260211-232328-2ade/cyl_Re40/cyl_Re40_U.png` **input** ``` { "path": "/work/20260211-232328-2ade/cyl_Re40/cyl_Re40_U.png" } ``` **output** ``` [image/png, 241080 bytes] /work/20260211-232328-2ade/cyl_Re40/cyl_Re40_U.png — 1500x820 image/png, 241078 bytes ``` ### tool: read_file `/work/20260211-232328-2ade/cyl_Re40/cyl_Re40_mesh.png` **input** ``` { "path": "/work/20260211-232328-2ade/cyl_Re40/cyl_Re40_mesh.png" } ``` **output** ``` [image/png, 433890 bytes] /work/20260211-232328-2ade/cyl_Re40/cyl_Re40_mesh.png — 1100x1100 image/png, 433889 bytes ``` ### tool: job_check `job_id=00832411-7f80-4123-9049-d702f51142a9` **input** ``` { "job_id": "00832411-7f80-4123-9049-d702f51142a9" } ``` **output** ``` job 00832411-7f80-4123-9049-d702f51142a9 name=sweep1 status=running log_size=68 running_for=2.8min log: bytes 26–68, eof=True cyl_Re40_far done rc=0 cyl_Re20 done rc=0 ``` ### tool: bash `cd /work/20260211-232328-2ade && python3 - <<'EOF'` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && python3 - <<'EOF'\nimport re\np='tools/render.py'\ns=open(p).read()\ns=s.replace(\"\"\"seed = pv.LineSource((xmin*0.98, ymin*0.98, 0.05), (xmin*0.98, ymax*0.98, 0.05), 60)\nstrm = cc.streamlines_from_source(seed.output, vectors='U', integration_direction='both',\n max_length=3.0, initial_step_length=0.05)\"\"\",\n\"\"\"import numpy as _np\nsp = [(xmin*0.98, y, 0.05) for y in _np.linspace(ymin*0.98, ymax*0.98, 60)]\nsp += [(R+dx, dy, 0.05) for dx in _np.linspace(0.02*D, 2.2*D, 14)\n for dy in (-0.35*D, -0.15*D, 0.15*D, 0.35*D)]\nseed = pv.PolyData(_np.array(sp))\nstrm = cc.streamlines_from_source(seed, vectors='U', integration_direction='both',\n max_length=6.0, initial_step_length=0.02)\"\"\")\ns=s.replace(\"\"\"pl.add_mesh(slc.clip_box([-4*D, 4*D, -4*D, 4... ``` **output** ``` exit_code: 0 [took 36s] PyVista error in handling VTK error message: 'WARNING:root:WARNING:root:WARNING:root:WARNING:root:WARNING:root:WARNING:root:WARNING:root:WARNING:r' ... (1858 characters) rc=0 ``` ### tool: read_file `/work/20260211-232328-2ade/cyl_Re40/cyl_Re40_U.png` **input** ``` { "path": "/work/20260211-232328-2ade/cyl_Re40/cyl_Re40_U.png" } ``` **output** ``` [image/png, 313635 bytes] /work/20260211-232328-2ade/cyl_Re40/cyl_Re40_U.png — 1500x820 image/png, 313634 bytes ``` ### tool: read_file `/work/20260211-232328-2ade/cyl_Re40/cyl_Re40_mesh.png` **input** ``` { "path": "/work/20260211-232328-2ade/cyl_Re40/cyl_Re40_mesh.png" } ``` **output** ``` [image/png, 434319 bytes] /work/20260211-232328-2ade/cyl_Re40/cyl_Re40_mesh.png — 1100x1100 image/png, 434319 bytes ``` ### you can you generate a few images of the mesh, and give some early plots ### tool: job_check `job_id=00832411-7f80-4123-9049-d702f51142a9` **input** ``` { "job_id": "00832411-7f80-4123-9049-d702f51142a9" } ``` **output** ``` job 00832411-7f80-4123-9049-d702f51142a9 name=sweep1 status=running log_size=68 running_for=4.4min log: bytes 68–68, eof=True ``` ### agent Sweep is nearly done (only the fine mesh still running). Making proper mesh figures and plots now. ### tool: write_file `/work/20260211-232328-2ade/tools/mesh_figs.py` **input** ``` { "path": "/work/20260211-232328-2ade/tools/mesh_figs.py", "content": "#!/usr/bin/env python3\n\"\"\"Mesh figures at three zoom levels, drawn from the polyMesh points (true quads).\"\"\"\nimport sys, os\nimport numpy as np\nimport matplotlib\nmatplotlib.use('Agg')\nimport matplotlib.pyplot as plt\nfrom matplotlib.collections import LineCollection\n\ncase = sys.argv[1]\ntag = os.path.basename(case)\nD = 0.1\n\n# read points and faces of the z=0 'back' patch straight from polyMesh\npm = os.path.join(case, 'constant/polyMesh')\ndef read_list(fn, parse):\n txt = open(os.path.join(pm, fn)).read()\n i = txt.index('(', txt.index('FoamFile') + txt[txt.index('FoamFile'):].index('}'))\n depth, out, buf = 0, [], ''\n body = txt[i:]\n end = body.rindex(')')\n return parse(body[1:end])\n\npts_txt = read_list('points', lambda s: s)\npts = np.array([[float(v) for v in ln.strip()[1... ``` **output** ``` wrote 2278 bytes to /work/20260211-232328-2ade/tools/mesh_figs.py ``` ### tool: bash `cd /work/20260211-232328-2ade && head -22 cyl_Re40/constant/polyMesh/faces && ...` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && head -22 cyl_Re40/constant/polyMesh/faces && python3 tools/mesh_figs.py cyl_Re40" } ``` **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 faceList; location "constant/polyMesh"; object faces; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // 143616 ( 4(1 142 4795 4654) wrote cyl_Re40/cyl_Re40_meshfig.png ``` ### tool: read_file `/work/20260211-232328-2ade/cyl_Re40/cyl_Re40_meshfig.png` **input** ``` { "path": "/work/20260211-232328-2ade/cyl_Re40/cyl_Re40_meshfig.png" } ``` **output** ``` [image/png, 1827135 bytes] /work/20260211-232328-2ade/cyl_Re40/cyl_Re40_meshfig.png — 2145x741 image/png, 1827134 bytes ``` ### tool: job_check `job_id=00832411-7f80-4123-9049-d702f51142a9` **input** ``` { "job_id": "00832411-7f80-4123-9049-d702f51142a9" } ``` **output** ``` job 00832411-7f80-4123-9049-d702f51142a9 name=sweep1 status=running log_size=68 running_for=5.5min log: bytes 68–68, eof=True ``` ### tool: bash `cd /work/20260211-232328-2ade && tail -3 cyl_Re40_fine/log.simpleFoam | head -...` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && tail -3 cyl_Re40_fine/log.simpleFoam | head -2; for c in cyl_Re20 cyl_Re40_far cyl_Re40_coarse; do echo \"== $c\"; grep -m1 \"converged in\" $c/log.simpleFoam; python3 tools/post.py $c 2>/dev/null | tr -d '\\n '; echo; done" } ``` **output** ``` exit_code: 0 Time = 3921 == cyl_Re20 SIMPLE solution converged in 2674 iterations {"case":"cyl_Re20","Cd":2.03224714,"Cd_visc":NaN,"Cl":-1.78440278e-08,"Lw_over_D":0.9124299831171685,"theta_sep_deg":43.3191187722041,"Cp_base":-0.5455499887466431,"Cp_stag":1.2852063179016113,"ncells":35840} == cyl_Re40_far SIMPLE solution converged in 2050 iterations {"case":"cyl_Re40_far","Cd":1.50761598,"Cd_visc":NaN,"Cl":-1.35159677e-08,"Lw_over_D":2.231014620137243,"theta_sep_deg":53.26424886523761,"Cp_base":-0.47925394773483276,"Cp_stag":1.143908977508545,"ncells":42240} == cyl_Re40_coarse SIMPLE solution converged in 872 iterations {"case":"cyl_Re40_coarse","Cd":1.52155157,"Cd_visc":NaN,"Cl":-5.55974163e-09,"Lw_over_D":2.2126538817968475,"theta_sep_deg":53.12066731996722,"Cp_base":-0.4822319746017456,"Cp_stag":1.1501513719558716,"ncells":14400} ``` ### tool: write_file `/work/20260211-232328-2ade/tools/plots.py` **input** ``` { "path": "/work/20260211-232328-2ade/tools/plots.py", "content": "#!/usr/bin/env python3\nimport os, re, json\nimport numpy as np\nimport matplotlib; matplotlib.use('Agg')\nimport matplotlib.pyplot as plt\n\nW = '/work/20260211-232328-2ade'\nos.chdir(W)\n\ndef residuals(case):\n it, r = [], {'Ux': [], 'Uy': [], 'p': []}\n n = 0\n for ln in open(f'{case}/log.simpleFoam'):\n m = re.match(r'^Time = (\\d+)', ln)\n if m: n = int(m.group(1)); it.append(n)\n for k in r:\n mm = re.search(rf'Solving for {k}, Initial residual = ([\\d.eE+-]+)', ln)\n if mm and len(r[k]) < len(it): r[k].append(float(mm.group(1)))\n L = min(len(it), *[len(v) for v in r.values()])\n return np.array(it[:L]), {k: np.array(v[:L]) for k, v in r.items()}\n\ndef coeffs(case):\n f = f'{case}/postProcessing/forceCoeffs1/0/coefficient.dat'\n d = np.array([[fl... ``` **output** ``` wrote 3985 bytes to /work/20260211-232328-2ade/tools/plots.py ``` ### tool: job_check `job_id=00832411-7f80-4123-9049-d702f51142a9` **input** ``` { "job_id": "00832411-7f80-4123-9049-d702f51142a9" } ``` **output** ``` job 00832411-7f80-4123-9049-d702f51142a9 name=sweep1 status=exited exit_code=0 end_reason=completed log_size=92 ran_for=6.5min log: bytes 68–92, eof=True cyl_Re40_fine done rc=0 ``` ### tool: bash `cd /work/20260211-232328-2ade && grep -m1 "converged in" cyl_Re40_fine/log.sim...` exit 1 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && grep -m1 \"converged in\" cyl_Re40_fine/log.simpleFoam; python3 tools/post.py cyl_Re40_fine 2>/dev/null | tr -d '\\n '; echo; python3 tools/post.py cyl_Re40 >/dev/null 2>&1; python3 tools/plots.py" } ``` **output** ``` exit_code: 1 SIMPLE solution converged in 4125 iterations {"case":"cyl_Re40_fine","Cd":1.51838034,"Cd_visc":NaN,"Cl":-2.2987792e-08,"Lw_over_D":2.2485394315311895,"theta_sep_deg":53.41237693492652,"Cp_base":-0.4774894714355469,"Cp_stag":1.1627856492996216,"ncells":76800} fig1 Traceback (most recent call last): File "/__modal/volumes/vo-T9FaBsi3H3bYZMAzJFmtee/20260211-232328-2ade/tools/plots.py", line 78, in fig.tight_layout(); fig.savefig('fig2_results.png', dpi=130) ^^^^^^^^^^^^^^^^^^ File "/usr/local/lib/python3.12/dist-packages/matplotlib/figure.py", line 3665, in tight_layout engine.execute(self) File "/usr/local/lib/python3.12/dist-packages/matplotlib/layout_engine.py", line 188, in execute kwargs = get_tight_layout_figure( ^^^^^^^^^^^^^^^^^^^^^^^^ File "/usr/local/lib/python3.12/dist-packages/matplotlib/_tight_layout.py", line 266, in get_tight_layout_figure kwargs = _auto_adjust_subplotpars(fig, renderer, ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/usr/local/lib/python3.12/dist-packages/matplotlib/_tight_layout.py", line 82, in _auto_adjust_subplotpars bb += [martist._get_tightbbox_for_layout_only(ax, renderer)] ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/usr/local/lib/python3.12/dist-packages/matplotlib/artist.py", line 1485, in _get_tightbbox_for_layout_only return ``` ### tool: bash `cd /work/20260211-232328-2ade && sed -i 's|\\\\frac12 U_\\\\infty\^2|\\\\frac{...` exit 1 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && sed -i 's|\\\\\\\\frac12 U_\\\\\\\\infty\\^2|\\\\\\\\frac{1}{2} U_\\\\\\\\infty^2|' tools/plots.py && grep -n 'C_p =' tools/plots.py && python3 tools/plots.py" } ``` **output** ``` exit_code: 1 57:ax[0].set_ylabel(r'$C_p = p/(\frac12 U_\infty^2)$') fig1 Traceback (most recent call last): File "/__modal/volumes/vo-T9FaBsi3H3bYZMAzJFmtee/20260211-232328-2ade/tools/plots.py", line 78, in fig.tight_layout(); fig.savefig('fig2_results.png', dpi=130) ^^^^^^^^^^^^^^^^^^ File "/usr/local/lib/python3.12/dist-packages/matplotlib/figure.py", line 3665, in tight_layout engine.execute(self) File "/usr/local/lib/python3.12/dist-packages/matplotlib/layout_engine.py", line 188, in execute kwargs = get_tight_layout_figure( ^^^^^^^^^^^^^^^^^^^^^^^^ File "/usr/local/lib/python3.12/dist-packages/matplotlib/_tight_layout.py", line 266, in get_tight_layout_figure kwargs = _auto_adjust_subplotpars(fig, renderer, ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/usr/local/lib/python3.12/dist-packages/matplotlib/_tight_layout.py", line 82, in _auto_adjust_subplotpars bb += [martist._get_tightbbox_for_layout_only(ax, renderer)] ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/usr/local/lib/python3.12/dist-packages/matplotlib/artist.py", line 1485, in _get_tightbbox_for_layout_only return obj.get_tightbbox(*args, **{**kwargs, "for_layout_only": True}) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/usr/local/lib/python3.12/dist-packages/matplotlib/axes/ ``` ### tool: bash `cd /work/20260211-232328-2ade && python3 - <<'EOF'` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && python3 - <<'EOF'\np='tools/plots.py'; s=open(p).read()\ns=s.replace(r\"$C_p = p/(\\frac12 U_\\infty^2)$\", r\"$C_p = p/(0.5\\,U_\\infty^2)$\")\nopen(p,'w').write(s)\nEOF\npython3 tools/plots.py" } ``` **output** ``` exit_code: 0 fig1 fig2 case cells Cd Lw/D theta_sep Cp_base cyl_Re20 35840 2.0322 0.912 43.32 -0.546 cyl_Re40_coarse 14400 1.5216 2.213 53.12 -0.482 cyl_Re40 35840 1.5192 2.239 53.32 -0.479 cyl_Re40_fine 76800 1.5184 2.249 53.41 -0.477 cyl_Re40_far 42240 1.5076 2.231 53.26 -0.479 ``` ### tool: read_file `/work/20260211-232328-2ade/fig1_convergence.png` **input** ``` { "path": "/work/20260211-232328-2ade/fig1_convergence.png" } ``` **output** ``` [image/png, 113847 bytes] /work/20260211-232328-2ade/fig1_convergence.png — 1625x598 image/png, 113847 bytes ``` ### tool: read_file `/work/20260211-232328-2ade/fig2_results.png` **input** ``` { "path": "/work/20260211-232328-2ade/fig2_results.png" } ``` **output** ``` [image/png, 168441 bytes] /work/20260211-232328-2ade/fig2_results.png — 2210x624 image/png, 168439 bytes ``` ### tool: bash `cd /work/20260211-232328-2ade && python3 - <<'EOF'` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && python3 - <<'EOF'\np='tools/render.py'; s=open(p).read()\ns=s.replace(\"\"\"sp += [(R+dx, dy, 0.05) for dx in _np.linspace(0.02*D, 2.2*D, 14)\n for dy in (-0.35*D, -0.15*D, 0.15*D, 0.35*D)]\"\"\",\n\"\"\"sp += [(R+dx, dy, 0.05) for dx in (0.15*D, 0.45*D, 0.8*D)\n for dy in (-0.3*D, -0.12*D, 0.12*D, 0.3*D)]\"\"\")\nopen(p,'w').write(s)\n\np='tools/plots.py'; s=open(p).read()\nold=s[s.index(\"lit = {'cyl_Re20'\"):s.index(\"fig.tight_layout(); fig.savefig('fig2_results.png'\")]\nnew = \"\"\"lit = {'cyl_Re20': (2.00, 2.09, 'Re=20 published'), 'cyl_Re40': (1.48, 1.56, 'Re=40 published')}\nnames = list(cases); vals = [S[c]['Cd'] for c in names]\nfor key, (lo, hi, lab) in lit.items():\n ax[2].axhspan(lo, hi, color='0.85', zorder=0)\n ax[2].text(len(names)-0.45, 0.5*(lo+hi), lab, ha='right', va='cent... ``` **output** ``` exit_code: 0 [took 32s] fig1 fig2 case cells Cd Lw/D theta_sep Cp_base cyl_Re20 35840 2.0322 0.912 43.32 -0.546 cyl_Re40_coarse 14400 1.5216 2.213 53.12 -0.482 cyl_Re40 35840 1.5192 2.239 53.32 -0.479 cyl_Re40_fine 76800 1.5184 2.249 53.41 -0.477 cyl_Re40_far 42240 1.5076 2.231 53.26 -0.479 PyVista error in handling VTK error message: 'WARNING:root:WARNING:root:WARNING:root:WARNING:root:WARNING:root:WARNING:root:WARNING:root:WARNING:r' ... (1858 characters) PyVista error in handling VTK error message: 'WARNING:root:WARNING:root:WARNING:root:WARNING:root:WARNING:root:WARNING:root:WARNING:root:WARNING:r' ... (1858 characters) wrote cyl_Re40_fine/cyl_Re40_fine_meshfig.png cyl_Re20/cyl_Re20_U.png cyl_Re20/cyl_Re20_mesh.png cyl_Re20/cyl_Re20_p.png cyl_Re40/cyl_Re40_U.png cyl_Re40/cyl_Re40_mesh.png cyl_Re40/cyl_Re40_meshfig.png cyl_Re40/cyl_Re40_p.png fig1_convergence.png fig2_results.png ``` ### tool: read_file `/work/20260211-232328-2ade/cyl_Re40/cyl_Re40_U.png` **input** ``` { "path": "/work/20260211-232328-2ade/cyl_Re40/cyl_Re40_U.png" } ``` **output** ``` [image/png, 305316 bytes] /work/20260211-232328-2ade/cyl_Re40/cyl_Re40_U.png — 1500x820 image/png, 305314 bytes ``` ### tool: read_file `/work/20260211-232328-2ade/cyl_Re40/cyl_Re40_p.png` **input** ``` { "path": "/work/20260211-232328-2ade/cyl_Re40/cyl_Re40_p.png" } ``` **output** ``` [image/png, 276189 bytes] /work/20260211-232328-2ade/cyl_Re40/cyl_Re40_p.png — 1500x820 image/png, 276189 bytes ``` ### tool: read_file `/work/20260211-232328-2ade/fig2_results.png` **input** ``` { "path": "/work/20260211-232328-2ade/fig2_results.png" } ``` **output** ``` [image/png, 173622 bytes] /work/20260211-232328-2ade/fig2_results.png — 2210x624 image/png, 173620 bytes ``` ### tool: read_file `/work/20260211-232328-2ade/cyl_Re20/cyl_Re20_U.png` **input** ``` { "path": "/work/20260211-232328-2ade/cyl_Re20/cyl_Re20_U.png" } ``` **output** ``` [image/png, 272034 bytes] /work/20260211-232328-2ade/cyl_Re20/cyl_Re20_U.png — 1500x820 image/png, 272033 bytes ``` ### tool: write_file `/work/20260211-232328-2ade/README.md` **input** ``` { "path": "/work/20260211-232328-2ade/README.md", "content": "# Steady 2D flow past a circular cylinder — first results\n\nSolver `simpleFoam` (steady, incompressible, **laminar** — no turbulence model),\nOpenFOAM v2512. Geometry: cylinder D = 0.1 m, single-cell-thick 2D domain\n(front/back `empty`), circular O-grid far field.\n\nNon-dimensionalisation: U_inf = 1 m/s, D = 0.1 m, nu set to give the target Re\n(Re = 40 -> nu = 2.5e-3 m^2/s; Re = 20 -> nu = 5.0e-3). p is kinematic (m^2/s^2),\nso Cp = p / (0.5 U_inf^2) and rhoInf = 1 in the force coefficients — everything\nreported here is dimensionless and independent of the actual fluid.\n\n## Mesh\n\nPure quad O-grid written by `tools/make_mesh.py`: 8 sectors x 45 deg, radial\ngrading from a wall cell of D/125 out to the far field. Base mesh 35 840 cells,\nfar field at 40 D. `checkMesh`: max non-orthogonality ~ 0 (2e-6), max skewness\... ``` **output** ``` wrote 2898 bytes to /work/20260211-232328-2ade/README.md ``` ### tool: fetch `paths=['/work/20260211-232328-2ade/cyl_Re40/cyl_Re40_meshfig.png', '/work/2026...` **input** ``` { "paths": [ "/work/20260211-232328-2ade/cyl_Re40/cyl_Re40_meshfig.png", "/work/20260211-232328-2ade/fig1_convergence.png", "/work/20260211-232328-2ade/fig2_results.png", "/work/20260211-232328-2ade/cyl_Re40/cyl_Re40_U.png", "/work/20260211-232328-2ade/cyl_Re40/cyl_Re40_p.png", "/work/20260211-232328-2ade/cyl_Re20/cyl_Re20_U.png", "/work/20260211-232328-2ade/README.md" ] } ``` **output** ``` copied 7 file(s) to the user's machine: C:\Users\reach\Documents\playing\studies\20260211-232328-2ade\files\20260211-232328-2ade\cyl_Re40\cyl_Re40_meshfig.png C:\Users\reach\Documents\playing\studies\20260211-232328-2ade\files\20260211-232328-2ade\fig1_convergence.png C:\Users\reach\Documents\playing\studies\20260211-232328-2ade\files\20260211-232328-2ade\fig2_results.png C:\Users\reach\Documents\playing\studies\20260211-232328-2ade\files\20260211-232328-2ade\cyl_Re40\cyl_Re40_U.png C:\Users\reach\Documents\playing\studies\20260211-232328-2ade\files\20260211-232328-2ade\cyl_Re40\cyl_Re40_p.png C:\Users\reach\Documents\playing\studies\20260211-232328-2ade\files\20260211-232328-2ade\cyl_Re20\cyl_Re20_U.png C:\Users\reach\Documents\playing\studies\20260211-232328-2ade\files\20260211-232328-2ade\README.md ``` ### agent Done — five converged runs, mesh figures and plots are on your machine (and in `/work/20260211-232328-2ade/`). **What I built.** A pure-quad O-grid around a D = 0.1 m cylinder (8 sectors, radial grading from a D/125 wall cell out to a circular far field), one cell thick with `empty` front/back. `checkMesh`: max non-orthogonality ≈ 0, skewness 0.016, aspect ratio 1.53. Steady `simpleFoam`, **laminar** (no turbulence model), U∞ = 1 m/s with ν set to hit the target Re — so all reported numbers are dimensionless. **Mesh** — `cyl_Re40_meshfig.png` shows it at three zooms (full 40 D domain, ±5 D, wall). **Results**, all converged to residuals < 1e-7: | case | cells | far field | Cd | L_wake/D | θ_sep | Cp,base | |---|---|---|---|---|---|---| | Re 20, base | 35 840 | 40 D | 2.032 | 0.912 | 43.3° | −0.546 | | Re 40, coarse | 14 400 | 40 D | 1.522 | 2.213 | 53.1° | −0.482 | | Re 40, base | 35 840 | 40 D | 1.519 | 2.239 | 53.3° | −0.479 | | Re 40, fine | 76 800 | 40 D | 1.518 | 2.249 | 53.4° | −0.477 | | Re 40, far field 80 D | 42 240 | 80 D | 1.508 | 2.231 | 53.3° | −0.479 | Published ranges are Cd ≈ 2.00–2.09 at Re 20 and 1.48–1.56 at Re 40, with L/D ≈ 0.91 and 2.2–2.35 — both cases sit inside. Cl is ~1e-8, i.e. symmetric as a steady solution should be. Grid effect coarse→fine is 0.2 %; doubling the far-field radius moves Cd by −0.7 %, so **domain size, not grid, is the dominant discretisation error** here. **Two caveats I want to be explicit about.** The separation angle comes from tangential velocity sampled on a circle inside the first cell layer, not from patch wall-shear-stress — good to a fraction of a degree, but not the patch-integrated quantity. And steady laminar is only *physically* right below the shedding onset at Re ≈ 47; above that a steady solution still converges, but it isn't the flow you'd observe. **Which is why I should ask what you actually meant by "airflow."** These runs are the classic steady benchmark. If you meant air at an engineering speed — say 10 m/s past a 10 mm rod, Re ≈ 6 700 — the real flow sheds vortices and there are two honest options: a steady RANS (k-ω SST) that gives a time-averaged Cd but no shedding, or an unsteady `pimpleFoam` run that resolves the Kármán street and gives Strouhal number plus a Cd/Cl history. Both are straightforward from this mesh. Tell me the diameter and velocity you have in mind, or just say "high-Re air" and I'll pick a representative case and run both. ### you is this transient or steady state? ### agent Steady state. Concretely, in what I ran: ### tool: bash `cd /work/20260211-232328-2ade/cyl_Re40 && grep -A2 ddtSchemes system/fvSchemes...` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade/cyl_Re40 && grep -A2 ddtSchemes system/fvSchemes; grep -E \"application|endTime|deltaT\" system/controlDict; echo ---; grep -A4 \"residualControl\" system/fvSolution" } ``` **output** ``` exit_code: 0 ddtSchemes { default steadyState; } gradSchemes { default Gauss linear; } divSchemes application simpleFoam; stopAt endTime; endTime 5000; deltaT 1; --- residualControl { p 1e-7; U 1e-7; } } relaxationFactors { fields { p 0.3; } ``` ### agent **Steady state**, in both senses — and they're worth separating, because only one of them is a choice I made. **Numerically:** `simpleFoam` with `ddtSchemes { default steadyState; }`. The ∂U/∂t term is dropped from the momentum equation entirely. The "Time = 1965" in the log is not physical time — it is the SIMPLE iteration counter, and `deltaT 1` is just the increment on that counter. There is no CFL number, no timestep, and the intermediate "times" are not a movie of the flow developing; they are a relaxation path to the fixed point. The run stopped because the residuals hit the 1e-7 `residualControl` floor, i.e. the field stopped changing from iteration to iteration. **Physically:** at Re = 20 and 40 that is also the right answer. Flow past a circular cylinder is genuinely steady — a fixed, symmetric pair of standing recirculation vortices — up to the Hopf bifurcation at Re ≈ 47. Above that the real flow sheds a Kármán vortex street and is unconditionally unsteady. So my two cases sit safely below the bifurcation, and the steady solution is the physical solution, which is exactly why the benchmark Cd values I compared against exist as single numbers rather than time averages. The trap, and the reason I flagged it in the summary: `simpleFoam` will happily converge at Re = 6 700 too, and hand you a clean symmetric wake with tidy residuals. That solution is a mathematical fixed point of the steady equations that is *linearly unstable* — nothing you'd ever measure. At those Reynolds numbers "steady" has to mean either a time-averaged RANS result or an unsteady solve you average yourself. So: if you want the drag number for one of these low-Re cases, what's above is it. If you want air at a real speed, that needs `pimpleFoam` with actual timesteps, and I'd report Cd as a mean with its oscillation amplitude plus the Strouhal number. Say the word and the diameter/velocity, and I'll set it running on this same mesh. ### you can you run a transient and produce a gif? ### agent Good — let's do the classic unsteady case: **Re = 100**, where the wake sheds a Kármán street. That's still 2D-laminar (the real flow stays 2D up to Re ≈ 190), so it's a case I can validate against published Strouhal and drag data rather than just make a pretty picture. First a wake-friendly mesh: ### tool: bash `cd /work/20260211-232328-2ade && tools/clone_case.sh cyl_tr_Re100 1.0e-3 --Ro ...` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && tools/clone_case.sh cyl_tr_Re100 1.0e-3 --Ro 25 --nr 200 --nc 56 --d1 0.0005 && cat cyl_tr_Re100/log.mesh && python3 - <<'EOF'\nimport numpy as np\nD=0.1; Ri=0.05; Ro=2.5; n=200; d1=5e-4\n# recover per-cell expansion\nfrom math import isclose\nlo,hi=1+1e-12,2\nf=lambda r: d1*(r**n-1)/(r-1)-(Ro-Ri)\nfor _ in range(200):\n m=.5*(lo+hi)\n if f(m)<0: lo=m\n else: hi=m\nr=.5*(lo+hi)\nrad=Ri; \nprint(\" radius/D dr/D ds/D (circ)\")\nfor i in range(n):\n dr=d1*r**i\n if i%20==0 or rad<0.3:\n pass\n rad+=dr\nrad=Ri\nfor i in range(n):\n dr=d1*r**i\n if abs((rad/D)-round(rad/D))<0.02 and rad/D<=25 and round(rad/D) in (1,2,3,5,8,10,15,20,25):\n print(f\" {rad/D:6.1f} {dr/D:7.4f} {2*np.pi*rad/448/D:7.4f}\")\n rad+=dr\nEOF" } ``` **output** ``` exit_code: 0 cyl_tr_Re100 ready: cells = 89600 Ri=0.05 Ro=2.5 first cell dr=5.000e-04 last dr=5.840e-02 expansion/cell=1.02421 grading=116.80 surface arc length ds=7.012e-04 (dr/ds at wall = 0.71) cells = 89600 wrote system/blockMeshDict radius/D dr/D ds/D (circ) 1.0 0.0169 0.0139 1.0 0.0173 0.0142 2.0 0.0410 0.0279 10.0 0.2353 0.1404 ``` ### agent Re = 100 needs a mesh that keeps the wake resolved, not just the boundary layer. Adding two-segment radial grading to the mesh generator: ### tool: bash `cd /work/20260211-232328-2ade && python3 - <<'PY'` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && python3 - <<'PY'\np='tools/make_mesh.py'; s=open(p).read()\ns=s.replace(\"\"\"ap.add_argument('--out', default='system/blockMeshDict')\"\"\",\n\"\"\"ap.add_argument('--out', default='system/blockMeshDict')\nap.add_argument('--seg', action='append', default=None,\n help='radius_in_D:target_cell_size_in_D breakpoint, repeatable. '\n 'Overrides --nr with a multi-graded radial distribution.')\"\"\")\n\ns=s.replace(\"\"\"# solve geometric expansion r: d1*(r^n - 1)/(r - 1) = L -> bisection\"\"\",\n\"\"\"if a.seg:\n # multi-segment radial grading: geometric within each segment\n bps = [(float(x.split(':')[0])*a.D, float(x.split(':')[1])*a.D) for x in a.seg]\n r0, ds = Ri, d1\n segs = []\n for rend, dend in bps:\n Ls = rend - r0\n g = (Ls - ds) / (Ls - dend)\n n = max(2, int(roun... ``` **output** ``` exit_code: 0 OK ``` ### tool: bash `cd /work/20260211-232328-2ade && rm -rf cyl_tr_Re100 && tools/clone_case.sh cy...` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && rm -rf cyl_tr_Re100 && tools/clone_case.sh cyl_tr_Re100 1.0e-3 --Ro 25 --nc 48 --d1 0.001 --seg 8:0.07 && cat cyl_tr_Re100/log.mesh && cd cyl_tr_Re100 && checkMesh 2>&1 | grep -E \"cells|non-ortho|skewness|aspect|Mesh OK|\\*\\*\\*\"" } ``` **output** ``` exit_code: 0 cyl_tr_Re100 ready: cells = 109824 wall ds = 8.181e-04 (0.0082 D) radial segments (length, ncells, expansion, d_start, d_end): 0.7500 243 E= 7.003 1.0000e-03 -> 7.0000e-03 (0.0100 D -> 0.0700 D) 1.7000 43 E= 17.144 7.0000e-03 -> 1.2001e-01 (0.0700 D -> 1.2001 D) cells = 109824 wall ds = 8.181e-04 (0.0082 D) wrote system/blockMeshDict cells: 109824 Overall number of cells of each type: Max aspect ratio = 2.8834648 OK. Mesh non-orthogonality Max: 3.1945285e-06 average: 0 Max skewness = 0.014252168 OK. Mesh OK. ``` ### agent Mesh: 110k cells, ≤0.07 D radially out to 8 D, wall cell D/100, max non-orthogonality ~0. Now the transient setup — impulsive start with a brief 5° inlet kick to trigger shedding rather than waiting for round-off to do it: ### tool: bash `cd /work/20260211-232328-2ade/cyl_tr_Re100 && cat > 0/U <<'EOF'` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade/cyl_tr_Re100 && cat > 0/U <<'EOF'\nFoamFile { version 2.0; format ascii; class volVectorField; object U; }\ndimensions [0 1 -1 0 0 0 0];\ninternalField uniform (1 0 0);\nboundaryField\n{\n inlet\n {\n type uniformFixedValue;\n uniformValue table\n (\n (0 (0.99619 0.08716 0))\n (1.0 (0.99619 0.08716 0))\n (1.5 (1 0 0))\n (10000 (1 0 0))\n );\n }\n outlet { type inletOutlet; inletValue uniform (0 0 0); value uniform (1 0 0); }\n cylinder { type noSlip; }\n \"(front|back)\" { type empty; }\n}\nEOF\ncat > system/fvSchemes <<'EOF'\nFoamFile { version 2.0; format ascii; class dictionary; object fvSchemes; }\nddtSchemes { default backward; }\ngradSchemes { default Gauss linear; }\ndivSchemes\n{\n default none;\n... ``` **output** ``` exit_code: 0 Processor 7: field transfer End ``` ### tool: job_start `export OMPI_ALLOW_RUN_AS_ROOT=1 OMPI_ALLOW_RUN_AS_ROOT_CONFIRM=1; mpirun -np 8...` **input** ``` { "cmd": "export OMPI_ALLOW_RUN_AS_ROOT=1 OMPI_ALLOW_RUN_AS_ROOT_CONFIRM=1; mpirun -np 8 pimpleFoam -parallel > log.pimpleFoam.stageA 2>&1; echo \"stageA rc=$?\"", "cwd": "/work/20260211-232328-2ade/cyl_tr_Re100", "name": "tr_stageA", "kill_on": [ "FOAM FATAL", "Floating point exception" ] } ``` **output** ``` started job cdc8bceb-01d2-4100-90bd-a7a6354af623 (tr_stageA) ``` ### tool: bash `sleep 60; cd /work/20260211-232328-2ade/cyl_tr_Re100 && grep -E "^(Time|Couran...` exit 0 **input** ``` { "cmd": "sleep 60; cd /work/20260211-232328-2ade/cyl_tr_Re100 && grep -E \"^(Time|Courant|deltaT)\" log.pimpleFoam.stageA | tail -6; tail -3 postProcessing/forceCoeffs1/0/coefficient.dat" } ``` **output** ``` exit_code: 0 [took 64s] Courant Number mean: 0.038120659 max: 0.89992765 deltaT = 0.00067520491 Time = 0.37950822 Courant Number mean: 0.038120437 max: 0.89977879 deltaT = 0.00067548636 Time = 0.3801837 0.37815781 1.37897205e+00 6.63938418e-01 7.15033636e-01 5.10952184e-02 2.55783277e-02 2.55168907e-02 3.07185130e-05 -2.55476092e-02 6.89486027e-01 1.30365087e-21 6.89486027e-01 -6.89486027e-01 0.37883301 1.37858578e+00 6.63762746e-01 7.14823031e-01 5.10602847e-02 2.55599425e-02 2.55003422e-02 2.98001402e-05 -2.55301423e-02 6.89292888e-01 1.30297505e-21 6.89292888e-01 -6.89292888e-01 0.37950822 1.37819767e+00 6.63586252e-01 7.14611418e-01 5.10251661e-02 2.55414662e-02 2.54836998e-02 2.88831868e-05 -2.55125830e-02 6.89098835e-01 1.30220650e-21 6.89098835e-01 -6.89098835e-01 ``` ### agent Running: ~0.38 s of physical time per minute of wall clock, dt ≈ 6.8e-4 (max Co 0.9). Stage A (12 s spin-up) will take ~30 min. Meanwhile, checking what I have for GIF assembly: ### tool: bash `python3 -c "import PIL, imageio" 2>&1 | tail -1; python3 -c "import PIL; print...` exit 0 **input** ``` { "cmd": "python3 -c \"import PIL, imageio\" 2>&1 | tail -1; python3 -c \"import PIL; print('PIL', PIL.__version__)\"; which ffmpeg convert 2>&1|head -3" } ``` **output** ``` exit_code: 0 ModuleNotFoundError: No module named 'imageio' PIL 12.3.0 ``` ### tool: write_file `/work/20260211-232328-2ade/tools/make_gif.py` **input** ``` { "path": "/work/20260211-232328-2ade/tools/make_gif.py", "content": "#!/usr/bin/env python3\n\"\"\"Assemble an animated GIF of spanwise vorticity (and optionally p) from a\ntransient OpenFOAM cylinder case.\"\"\"\nimport sys, os, glob, argparse\nimport numpy as np\nimport pyvista as pv\nfrom PIL import Image\npv.OFF_SCREEN = True\n\nap = argparse.ArgumentParser()\nap.add_argument('case')\nap.add_argument('--t0', type=float, default=0.0)\nap.add_argument('--t1', type=float, default=1e9)\nap.add_argument('--field', default='vorticity', choices=['vorticity', 'p', 'Umag'])\nap.add_argument('--clim', type=float, default=25.0)\nap.add_argument('--fps', type=int, default=20)\nap.add_argument('--width', type=int, default=1000)\nap.add_argument('--every', type=int, default=1)\nap.add_argument('--out', default=None)\na = ap.parse_args()\n\nD = 0.1\nxmin, xmax, ymin, ymax = -2.5*D, 13*D, -3.5*... ``` **output** ``` wrote 3031 bytes to /work/20260211-232328-2ade/tools/make_gif.py ``` ### tool: bash `sleep 240; cd /work/20260211-232328-2ade/cyl_tr_Re100 && grep "^Time = " log.p...` exit -1 **input** ``` { "cmd": "sleep 240; cd /work/20260211-232328-2ade/cyl_tr_Re100 && grep \"^Time = \" log.pimpleFoam.stageA | tail -1; awk 'NR>13{print $1, $2, $5}' postProcessing/forceCoeffs1/0/coefficient.dat | tail -1" } ``` **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 `cd /work/20260211-232328-2ade/cyl_tr_Re100 && grep "^Time = " log.pimpleFoam.s...` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade/cyl_tr_Re100 && grep \"^Time = \" log.pimpleFoam.stageA | tail -1; awk 'NR>13{print $1, $2, $5}' postProcessing/forceCoeffs1/0/coefficient.dat | tail -1; ls" } ``` **output** ``` exit_code: 0 Time = 1.7464948 1.7457536 1.15924202e+00 4.31701020e-02 0 constant log.blockMesh log.decomposePar log.mesh log.pimpleFoam.stageA postProcessing processor0 processor1 processor2 processor3 processor4 processor5 processor6 processor7 system ``` ### tool: bash `cat > /work/20260211-232328-2ade/tools/watch_cl.py <<'EOF'` **input** ``` { "cmd": "cat > /work/20260211-232328-2ade/tools/watch_cl.py <<'EOF'\nimport numpy as np, sys\nf=sys.argv[1] if len(sys.argv)>1 else 'cyl_tr_Re100/postProcessing/forceCoeffs1/0/coefficient.dat'\nd=np.array([[float(x) for x in l.split()] for l in open(f) if not l.startswith('#')])\nt,cd,cl=d[:,0],d[:,1],d[:,4]\n# local maxima of Cl\npk=[(t[i],cl[i]) for i in range(1,len(t)-1) if cl[i]>cl[i-1] and cl[i]>=cl[i+1] and cl[i]>0]\nprint(f't = {t[-1]:.3f} s Cd = {cd[-1]:.4f} Cl = {cl[-1]:+.4f}')\nif len(pk)>1:\n print(' Cl peaks (t, value), last 8:')\n for a,b in pk[-8:]: print(f' {a:8.3f} {b:+.4f}')\n if len(pk)>2:\n T=np.diff([p[0] for p in pk[-6:]]).mean()\n print(f' period ~ {T:.4f} s -> St = D/(U T) = {0.1/T:.4f}')\nEOF\nsleep 200; cd /work/20260211-232328-2ade && python3 tools/watch_cl.py", "timeout_s": 240 } ``` **output** ``` bad_response (303): the service answered 303 with a body that is not JSON (the body was empty) ``` ### tool: bash `cd /work/20260211-232328-2ade && python3 tools/watch_cl.py` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && python3 tools/watch_cl.py" } ``` **output** ``` exit_code: 0 t = 3.214 s Cd = 1.1731 Cl = +0.1144 Cl peaks (t, value), last 8: 0.677 +0.0384 1.000 +0.0655 1.002 +0.0505 1.501 +0.0333 1.778 +0.0436 1.780 +0.0436 1.798 +0.0435 2.560 +0.0946 period ~ 0.3115 s -> St = D/(U T) = 0.3210 ``` ### tool: bash `sleep 270; cd /work/20260211-232328-2ade && python3 tools/watch_cl.py` **input** ``` { "cmd": "sleep 270; cd /work/20260211-232328-2ade && python3 tools/watch_cl.py", "timeout_s": 290 } ``` **output** ``` bad_response (303): the service answered 303 with a body that is not JSON (the body was empty) ``` ### tool: bash `cd /work/20260211-232328-2ade && python3 tools/watch_cl.py` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && python3 tools/watch_cl.py" } ``` **output** ``` exit_code: 0 t = 4.472 s Cd = 1.2802 Cl = +0.1005 Cl peaks (t, value), last 8: 1.002 +0.0505 1.501 +0.0333 1.778 +0.0436 1.780 +0.0436 1.798 +0.0435 2.560 +0.0946 3.294 +0.1382 3.959 +0.1800 period ~ 0.4363 s -> St = D/(U T) = 0.2292 ``` ### tool: bash `df -h /work | tail -1; du -sh /work/20260211-232328-2ade` exit 0 **input** ``` { "cmd": "df -h /work | tail -1; du -sh /work/20260211-232328-2ade" } ``` **output** ``` exit_code: 0 none 382G 0 382G 0% /__modal/volumes 155M /work/20260211-232328-2ade ``` ### you ? ### agent Sorry — status, plainly: the transient is running, ~40 % of the way through spin-up, and there's no GIF yet because there's nothing worth animating until the wake actually starts shedding. Where it is right now: ### tool: bash `cd /work/20260211-232328-2ade && python3 tools/watch_cl.py 2>&1 | head -4; gre...` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && python3 tools/watch_cl.py 2>&1 | head -4; grep \"^Time = \" cyl_tr_Re100/log.pimpleFoam.stageA | tail -1" } ``` **output** ``` exit_code: 0 [took 10s] t = 7.875 s Cd = 1.3393 Cl = -0.2760 Cl peaks (t, value), last 8: 3.294 +0.1382 3.959 +0.1800 Time = 7.8757033 ``` ### agent The Kármán instability is growing as it should: the lift oscillation amplitude has gone 0.09 → 0.14 → 0.18 → 0.28 over the last few minutes, heading for the published saturated value of ≈ 0.32 at Re = 100. Once it stops growing, the flow is periodic and worth filming. Setting up an automatic switch so no wall clock is wasted waiting on me — at t = 9.5 s it flips the case to dense frame writing: ### tool: job_start `cd /work/20260211-232328-2ade/cyl_tr_Re100` **input** ``` { "cmd": "cd /work/20260211-232328-2ade/cyl_tr_Re100\nwhile true; do\n T=$(grep \"^Time = \" log.pimpleFoam.stageA | tail -1 | awk '{print $3}')\n ok=$(python3 -c \"print(1 if float('${T:-0}')>9.5 else 0)\")\n if [ \"$ok\" = \"1\" ]; then\n sed -i -e 's/^endTime .*/endTime 12.5;/' \\\n -e 's/^writeInterval .*/writeInterval 0.02;/' \\\n -e 's/^purgeWrite .*/purgeWrite 0;/' system/controlDict\n echo \"switched to frame-writing at t=$T\"; break\n fi\n sleep 20\ndone", "cwd": "/work/20260211-232328-2ade", "name": "switch_to_frames" } ``` **output** ``` started job 5652f3ac-5531-4e33-8723-0754eaf5151f (switch_to_frames) ``` ### tool: bash `sleep 180; cd /work/20260211-232328-2ade && python3 tools/watch_cl.py 2>&1 | t...` **input** ``` { "cmd": "sleep 180; cd /work/20260211-232328-2ade && python3 tools/watch_cl.py 2>&1 | tail -6", "timeout_s": 200 } ``` **output** ``` bad_response (303): the service answered 303 with a body that is not JSON (the body was empty) ``` ### tool: bash `cd /work/20260211-232328-2ade && python3 tools/watch_cl.py 2>&1 | tail -6` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && python3 tools/watch_cl.py 2>&1 | tail -6" } ``` **output** ``` exit_code: 0 6.420 +0.3273 7.026 +0.3337 7.631 +0.3367 8.237 +0.3381 8.842 +0.3387 period ~ 0.6059 s -> St = D/(U T) = 0.1651 ``` ### agent Saturated, and it validates beautifully: - **St = 0.1651** (published Re=100: 0.164–0.167) - **Cl amplitude = ±0.339** (published 0.32–0.34) Waiting on the frame-writing window now. ### tool: job_check `job_id=5652f3ac-5531-4e33-8723-0754eaf5151f` **input** ``` { "job_id": "5652f3ac-5531-4e33-8723-0754eaf5151f" } ``` **output** ``` job 5652f3ac-5531-4e33-8723-0754eaf5151f name=switch_to_frames status=running log_size=0 running_for=3.3min log: bytes 0–0, eof=True ``` ### tool: bash `sleep 170; cd /work/20260211-232328-2ade/cyl_tr_Re100 && grep "^Time = " log.p...` **input** ``` { "cmd": "sleep 170; cd /work/20260211-232328-2ade/cyl_tr_Re100 && grep \"^Time = \" log.pimpleFoam.stageA|tail -1; ls processor0 | head -20", "timeout_s": 190 } ``` **output** ``` bad_response (303): the service answered 303 with a body that is not JSON (the body was empty) ``` ### you whats happening? ### agent The `sleep` calls I use to pace myself keep tripping a harness timeout — that's the 303 noise, it doesn't touch the solve. Here's the actual state: ### tool: bash `cd /work/20260211-232328-2ade/cyl_tr_Re100 && grep "^Time = " log.pimpleFoam.s...` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade/cyl_tr_Re100 && grep \"^Time = \" log.pimpleFoam.stageA|tail -1; echo \"--- written time dirs:\"; ls processor0 | sort -g | tail -5; ls processor0 | grep -c \"^[0-9]\"; grep -E \"endTime|writeInterval\" system/controlDict" } ``` **output** ``` exit_code: 0 Time = 10.5331034 --- written time dirs: 10.44 10.46 10.48 10.5 10.52 55 stopAt endTime; endTime 12.5; writeInterval 0.02; writeInterval 1; writeInterval 1; ``` ### tool: job_check `job_id=5652f3ac-5531-4e33-8723-0754eaf5151f` **input** ``` { "job_id": "5652f3ac-5531-4e33-8723-0754eaf5151f" } ``` **output** ``` job 5652f3ac-5531-4e33-8723-0754eaf5151f name=switch_to_frames status=exited exit_code=0 end_reason=completed log_size=41 ran_for=6.3min log: bytes 0–41, eof=True switched to frame-writing at t=9.5281382 ``` ### agent Switch fired cleanly at t = 9.53 s; it's now writing a frame every 0.02 s and will stop at 12.5 s — 150 frames, about 5 shedding periods. ~10 min of solve left. Meanwhile let me test the GIF pipeline on a frame that already exists (reading the decomposed case directly, so I can skip `reconstructPar`): ### tool: bash `cd /work/20260211-232328-2ade && python3 - <<'EOF'` exit 1 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && python3 - <<'EOF'\nimport pyvista as pv\npv.OFF_SCREEN=True\nopen('cyl_tr_Re100/case.foam','w').close()\nr=pv.OpenFOAMReader('cyl_tr_Re100/case.foam')\nprint('case_type attr:', hasattr(r,'case_type'))\nr.case_type='decomposed'\nprint('n times', len(r.time_values), r.time_values[:3], r.time_values[-3:])\nEOF" } ``` **output** ``` exit_code: 1 case_type attr: False Traceback (most recent call last): File "", line 6, in File "/usr/local/lib/python3.12/dist-packages/pyvista/core/utilities/misc.py", line 530, in __setattr__ self._check_new_attribute(key) File "/usr/local/lib/python3.12/dist-packages/pyvista/core/utilities/misc.py", line 526, in _check_new_attribute raise PyVistaAttributeError(msg) pyvista.core.errors.PyVistaAttributeError: Attribute 'case_type' does not exist and cannot be added to class 'OpenFOAMReader' Use `pyvista.set_new_attribute` or `pyvista.allow_new_attributes` to set new attributes. Setting new private variables (with `_` prefix) is allowed by default. ``` ### tool: bash `cd /work/20260211-232328-2ade && python3 - <<'EOF'` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && python3 - <<'EOF'\nimport pyvista as pv\nr=pv.OpenFOAMReader('cyl_tr_Re100/case.foam')\nprint([m for m in dir(r.reader) if 'Case' in m or 'Decomp' in m])\nEOF" } ``` **output** ``` exit_code: 0 ['DecomposePolyhedraOff', 'DecomposePolyhedraOn', 'GetDecomposePolyhedra', 'SetDecomposePolyhedra'] ``` ### agent No decomposed-case support in this VTK build, so I'll `reconstructPar` after the solve. Checking progress: ### tool: bash `sleep 150; cd /work/20260211-232328-2ade/cyl_tr_Re100 && grep "^Time = " log.p...` **input** ``` { "cmd": "sleep 150; cd /work/20260211-232328-2ade/cyl_tr_Re100 && grep \"^Time = \" log.pimpleFoam.stageA|tail -1", "timeout_s": 170 } ``` **output** ``` bad_response (303): the service answered 303 with a body that is not JSON (the body was empty) ``` ### tool: bash `cd /work/20260211-232328-2ade/cyl_tr_Re100 && grep "^Time = " log.pimpleFoam.s...` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade/cyl_tr_Re100 && grep \"^Time = \" log.pimpleFoam.stageA|tail -1" } ``` **output** ``` exit_code: 0 Time = 12.0586207 ``` ### tool: job_check `job_id=cdc8bceb-01d2-4100-90bd-a7a6354af623 log_offset=100000000` **input** ``` { "job_id": "cdc8bceb-01d2-4100-90bd-a7a6354af623", "log_offset": 100000000 } ``` **output** ``` job cdc8bceb-01d2-4100-90bd-a7a6354af623 name=tr_stageA status=running log_size=0 running_for=29.1min log: bytes 100000000–100000000, eof=True ``` ### tool: bash `cd /work/20260211-232328-2ade/cyl_tr_Re100 && sleep 115; grep "^Time = " log.p...` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade/cyl_tr_Re100 && sleep 115; grep \"^Time = \" log.pimpleFoam.stageA|tail -1", "timeout_s": 140 } ``` **output** ``` exit_code: 0 [took 119s] Time = 12.5 ``` ### you ? ### agent Reached t = 12.5 s — solve done. Reconstructing the 150 frames now: ### tool: bash `cd /work/20260211-232328-2ade/cyl_tr_Re100 && tail -3 log.pimpleFoam.stageA; l...` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade/cyl_tr_Re100 && tail -3 log.pimpleFoam.stageA; ls processor0 | grep -c \"^[0-9]\"" } ``` **output** ``` exit_code: 0 End Finalising parallel run 154 ``` ### tool: job_start `cd /work/20260211-232328-2ade/cyl_tr_Re100 && reconstructPar -newTimes -time '...` **input** ``` { "cmd": "cd /work/20260211-232328-2ade/cyl_tr_Re100 && reconstructPar -newTimes -time '9.5:12.5' > log.reconstructPar 2>&1; echo \"rc=$?\"; ls -d [0-9]* | wc -l", "cwd": "/work/20260211-232328-2ade/cyl_tr_Re100", "name": "reconstruct" } ``` **output** ``` started job b257acc3-c318-404e-a15e-44125fbe31aa (reconstruct) ``` ### tool: bash `sleep 100; cd /work/20260211-232328-2ade/cyl_tr_Re100 && ls -d [0-9]* 2>/dev/n...` exit 0 **input** ``` { "cmd": "sleep 100; cd /work/20260211-232328-2ade/cyl_tr_Re100 && ls -d [0-9]* 2>/dev/null | wc -l; tail -2 log.reconstructPar", "timeout_s": 130 } ``` **output** ``` exit_code: 0 [took 103s] 63 No finite-area fields ``` ### tool: bash `sleep 110; cd /work/20260211-232328-2ade/cyl_tr_Re100 && ls -d [0-9]* 2>/dev/n...` exit 0 **input** ``` { "cmd": "sleep 110; cd /work/20260211-232328-2ade/cyl_tr_Re100 && ls -d [0-9]* 2>/dev/null | wc -l", "timeout_s": 130 } ``` **output** ``` exit_code: 0 [took 114s] 111 ``` ### tool: job_check `job_id=b257acc3-c318-404e-a15e-44125fbe31aa` **input** ``` { "job_id": "b257acc3-c318-404e-a15e-44125fbe31aa" } ``` **output** ``` job b257acc3-c318-404e-a15e-44125fbe31aa name=reconstruct status=running log_size=0 running_for=4.1min log: bytes 0–0, eof=True ``` ### you ?? ### agent Reconstruct is 111/150 done (~2 more min), then rendering. Here's a single frame from a time that's already reconstructed, so you can see what the animation will look like: ### tool: bash `cd /work/20260211-232328-2ade && python3 tools/make_gif.py cyl_tr_Re100 --t0 1...` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && python3 tools/make_gif.py cyl_tr_Re100 --t0 11.0 --t1 11.02 --field vorticity --out /tmp/one.gif 2>&1 | tail -2; cp cyl_tr_Re100/frames_vorticity/f0000.png preview_vorticity.png; echo done" } ``` **output** ``` exit_code: 0 [took 13s] frame 0 t=11 wrote /tmp/one.gif 0.1 MB done ``` ### tool: read_file `/work/20260211-232328-2ade/preview_vorticity.png` **input** ``` { "path": "/work/20260211-232328-2ade/preview_vorticity.png" } ``` **output** ``` [image/png, 84585 bytes] /work/20260211-232328-2ade/preview_vorticity.png — 1000x451 image/png, 84583 bytes ``` ### agent Textbook Kármán street. Let me kill the shading tint (flat colours) and build the full animation: ### tool: bash `cd /work/20260211-232328-2ade && sed -i "s/pl.add_mesh(clip, scalars=scal, cma...` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && sed -i \"s/pl.add_mesh(clip, scalars=scal, cmap=cmap, clim=clim, show_scalar_bar=False)/pl.add_mesh(clip, scalars=scal, cmap=cmap, clim=clim, show_scalar_bar=False, lighting=False)/;s/pl.add_mesh(circ, color='dimgray')/pl.add_mesh(circ, color='dimgray', lighting=False)/\" tools/make_gif.py && ls -d cyl_tr_Re100/[0-9]* | wc -l" } ``` **output** ``` exit_code: 0 133 ``` ### tool: bash `sleep 60; cd /work/20260211-232328-2ade && ls -d cyl_tr_Re100/[0-9]* | wc -l` exit 0 **input** ``` { "cmd": "sleep 60; cd /work/20260211-232328-2ade && ls -d cyl_tr_Re100/[0-9]* | wc -l", "timeout_s": 90 } ``` **output** ``` exit_code: 0 [took 64s] 151 ``` ### tool: job_start `cd /work/20260211-232328-2ade && python3 tools/make_gif.py cyl_tr_Re100 --t0 9...` **input** ``` { "cmd": "cd /work/20260211-232328-2ade && python3 tools/make_gif.py cyl_tr_Re100 --t0 9.54 --t1 12.5 --field vorticity --clim 25 --fps 20 --width 1000 && python3 tools/make_gif.py cyl_tr_Re100 --t0 9.54 --t1 12.5 --field p --fps 20 --width 1000", "cwd": "/work/20260211-232328-2ade", "name": "gif" } ``` **output** ``` started job 548dc82f-3dbe-48e9-a153-a991ef84dda9 (gif) ``` ### tool: bash `cd /work/20260211-232328-2ade && python3 - <<'EOF'` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && python3 - <<'EOF'\nimport numpy as np\nd=np.array([[float(x) for x in l.split()] for l in\n open('cyl_tr_Re100/postProcessing/forceCoeffs1/0/coefficient.dat') if not l.startswith('#')])\nt,cd,cl=d[:,0],d[:,1],d[:,4]\nm=t>9.0\nt,cd,cl=t[m],cd[m],cl[m]\n# uniform resample for FFT\nti=np.linspace(t[0],t[-1],4096); cli=np.interp(ti,t,cl); cdi=np.interp(ti,t,cd)\nf=np.fft.rfftfreq(len(ti),ti[1]-ti[0]); A=np.abs(np.fft.rfft(cli-cli.mean()))\nfs=f[np.argmax(A)]\nprint(f'window {t[0]:.2f}-{t[-1]:.2f} s')\nprint(f'shedding freq {fs:.4f} Hz -> St = f D / U = {fs*0.1:.4f}')\nprint(f'Cd mean {cdi.mean():.4f} amplitude {(cdi.max()-cdi.min())/2:.4f}')\nprint(f'Cl mean {cli.mean():+.5f} amplitude {(cli.max()-cli.min())/2:.4f}')\nfd=f[np.argmax(np.abs(np.fft.rfft(cdi-cdi.mean())))]\nprint(f'Cd oscillates at {fd:.4f} Hz = {fd/fs:.2f} x shedding freq')\nEO... ``` **output** ``` exit_code: 0 window 9.00-12.50 s shedding freq 1.7142 Hz -> St = f D / U = 0.1714 Cd mean 1.3451 amplitude 0.0102 Cl mean -0.00641 amplitude 0.3393 Cd oscillates at 3.4284 Hz = 2.00 x shedding freq ``` ### tool: bash `cd /work/20260211-232328-2ade && python3 - <<'EOF'` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && python3 - <<'EOF'\nimport numpy as np\nd=np.array([[float(x) for x in l.split()] for l in\n open('cyl_tr_Re100/postProcessing/forceCoeffs1/0/coefficient.dat') if not l.startswith('#')])\nt,cd,cl=d[:,0],d[:,1],d[:,4]\nm=t>7.5; t,cd,cl=t[m],cd[m],cl[m]\n# upward zero crossings of Cl, linearly interpolated -> precise period\nzc=[t[i]+(t[i+1]-t[i])*(-cl[i])/(cl[i+1]-cl[i]) for i in range(len(t)-1) if cl[i]<0<=cl[i+1]]\nzc=np.array(zc); T=np.diff(zc)\nprint(f'{len(zc)} zero crossings over t={t[0]:.2f}-{t[-1]:.2f}')\nprint(f'period T = {T.mean():.5f} +/- {T.std():.5f} s -> St = {0.1/T.mean():.4f}')\nprint(f'Cd mean {cd.mean():.4f} Cd amplitude {(cd.max()-cd.min())/2:.4f}')\nprint(f'Cl amplitude {(cl.max()-cl.min())/2:.4f}')\nEOF" } ``` **output** ``` exit_code: 0 8 zero crossings over t=7.50-12.50 period T = 0.60480 +/- 0.00008 s -> St = 0.1653 Cd mean 1.3449 Cd amplitude 0.0109 Cl amplitude 0.3393 ``` ### tool: job_check `job_id=548dc82f-3dbe-48e9-a153-a991ef84dda9` **input** ``` { "job_id": "548dc82f-3dbe-48e9-a153-a991ef84dda9" } ``` **output** ``` job 548dc82f-3dbe-48e9-a153-a991ef84dda9 name=gif status=running log_size=45 running_for=49s log: bytes 0–45, eof=True 149 frames, t = 9.54 .. 12.5 frame 0 t=9.54 ``` ### tool: write_file `/work/20260211-232328-2ade/tools/plot_transient.py` **input** ``` { "path": "/work/20260211-232328-2ade/tools/plot_transient.py", "content": "#!/usr/bin/env python3\nimport numpy as np\nimport matplotlib; matplotlib.use('Agg')\nimport matplotlib.pyplot as plt\n\nW = '/work/20260211-232328-2ade/'\nd = np.array([[float(x) for x in l.split()] for l in\n open(W+'cyl_tr_Re100/postProcessing/forceCoeffs1/0/coefficient.dat')\n if not l.startswith('#')])\nt, cd, cl = d[:, 0], d[:, 1], d[:, 4]\n\nfig, ax = plt.subplots(2, 2, figsize=(13.5, 7),\n gridspec_kw=dict(width_ratios=[2, 1]))\n\nax[0, 0].plot(t, cl, 'C0', lw=.8)\nax[0, 0].axvspan(9.54, 12.5, color='C2', alpha=.15)\nax[0, 0].text(11.0, -0.42, 'GIF window', ha='center', color='C2', fontsize=9)\nax[0, 0].axvspan(0, 1.5, color='C3', alpha=.12)\nax[0, 0].text(0.75, 0.42, '5$^\\\\circ$ inlet kick', ha='center', color='C3', fontsize=8)\nax[0, 0].set_ylabel('$... ``` **output** ``` wrote 2485 bytes to /work/20260211-232328-2ade/tools/plot_transient.py ``` ### tool: bash `cd /work/20260211-232328-2ade && python3 tools/plot_transient.py` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && python3 tools/plot_transient.py" } ``` **output** ``` exit_code: 0 wrote fig3_transient.png St=0.1653 Cd=1.3449 ``` ### tool: job_check `job_id=548dc82f-3dbe-48e9-a153-a991ef84dda9` **input** ``` { "job_id": "548dc82f-3dbe-48e9-a153-a991ef84dda9" } ``` **output** ``` job 548dc82f-3dbe-48e9-a153-a991ef84dda9 name=gif status=running log_size=62 running_for=1.6min log: bytes 45–62, eof=True frame 20 t=9.94 ``` ### tool: read_file `/work/20260211-232328-2ade/fig3_transient.png` **input** ``` { "path": "/work/20260211-232328-2ade/fig3_transient.png" } ``` **output** ``` [image/png, 174372 bytes] /work/20260211-232328-2ade/fig3_transient.png — 1755x910 image/png, 174372 bytes ``` ### tool: bash `cd /work/20260211-232328-2ade && python3 - <<'EOF'` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && python3 - <<'EOF'\np='tools/plot_transient.py'; s=open(p).read()\ns=s.replace(\"ax[0, 0].set_ylabel('$C_l$'); ax[0, 0].set_xlim(0, 12.5); ax[0, 0].grid(alpha=.3)\",\n \"ax[0, 0].set_ylabel('$C_l$'); ax[0, 0].set_xlim(0, 12.5)\\nax[0, 0].set_ylim(-0.45, 0.45); ax[0, 0].grid(alpha=.3)\")\ns=s.replace(\"loc='center', cellLoc='center')\",\"loc='center', cellLoc='center', colWidths=[0.42, 0.27, 0.34])\")\nopen(p,'w').write(s)\nEOF\npython3 tools/plot_transient.py" } ``` **output** ``` exit_code: 0 wrote fig3_transient.png St=0.1653 Cd=1.3449 ``` ### tool: job_check `job_id=548dc82f-3dbe-48e9-a153-a991ef84dda9` **input** ``` { "job_id": "548dc82f-3dbe-48e9-a153-a991ef84dda9" } ``` **output** ``` job 548dc82f-3dbe-48e9-a153-a991ef84dda9 name=gif status=running log_size=80 running_for=2.2min log: bytes 62–80, eof=True frame 40 t=10.34 ``` ### tool: bash `sleep 200; cd /work/20260211-232328-2ade && ls -la cyl_tr_Re100/*.gif 2>/dev/n...` **input** ``` { "cmd": "sleep 200; cd /work/20260211-232328-2ade && ls -la cyl_tr_Re100/*.gif 2>/dev/null; echo; tail -2 /work/.jobs/548dc82f-3dbe-48e9-a153-a991ef84dda9/log 2>/dev/null || true", "timeout_s": 230 } ``` **output** ``` bad_response (303): the service answered 303 with a body that is not JSON (the body was empty) ``` ### you where is it? ### tool: job_check `job_id=548dc82f-3dbe-48e9-a153-a991ef84dda9` **input** ``` { "job_id": "548dc82f-3dbe-48e9-a153-a991ef84dda9" } ``` **output** ``` job 548dc82f-3dbe-48e9-a153-a991ef84dda9 name=gif status=running log_size=135 running_for=5.1min log: bytes 80–135, eof=True frame 60 t=10.74 frame 80 t=11.14 frame 100 t=11.54 ``` ### tool: bash `cd /work/20260211-232328-2ade && ls -la cyl_tr_Re100/*.gif 2>/dev/null; ls cyl...` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && ls -la cyl_tr_Re100/*.gif 2>/dev/null; ls cyl_tr_Re100/frames_vorticity | wc -l; ls cyl_tr_Re100/frames_p 2>/dev/null | wc -l" } ``` **output** ``` exit_code: 0 107 0 ``` ### agent Vorticity GIF is at frame 107/149 — about 2 minutes from being written. (A second GIF of the pressure field is queued behind it.) Rendering is ~2 s/frame because each frame re-reads a 110k-cell time directory. ### tool: bash `sleep 150; cd /work/20260211-232328-2ade && ls -la cyl_tr_Re100/*.gif 2>/dev/n...` **input** ``` { "cmd": "sleep 150; cd /work/20260211-232328-2ade && ls -la cyl_tr_Re100/*.gif 2>/dev/null || echo \"not yet\"", "timeout_s": 180 } ``` **output** ``` bad_response (303): the service answered 303 with a body that is not JSON (the body was empty) ``` ### tool: bash `cd /work/20260211-232328-2ade && ls -la cyl_tr_Re100/*.gif 2>/dev/null || echo...` exit 0 **input** ``` { "cmd": "cd /work/20260211-232328-2ade && ls -la cyl_tr_Re100/*.gif 2>/dev/null || echo \"not yet\"" } ``` **output** ``` exit_code: 0 -rw-r--r-- 1 root root 10113296 Aug 24 16:35 cyl_tr_Re100/cyl_tr_Re100_vorticity.gif ``` ### agent It's there. Fetching it now: ### tool: fetch `paths=['/work/20260211-232328-2ade/cyl_tr_Re100/cyl_tr_Re100_vorticity.gif', '...` **input** ``` { "paths": [ "/work/20260211-232328-2ade/cyl_tr_Re100/cyl_tr_Re100_vorticity.gif", "/work/20260211-232328-2ade/fig3_transient.png" ] } ``` **output** ``` copied 2 file(s) to the user's machine: C:\Users\reach\Documents\playing\studies\20260211-232328-2ade\files\20260211-232328-2ade\cyl_tr_Re100\cyl_tr_Re100_vorticity.gif C:\Users\reach\Documents\playing\studies\20260211-232328-2ade\files\20260211-232328-2ade\fig3_transient.png ``` ### tool: read_file `/work/20260211-232328-2ade/fig3_transient.png` **input** ``` { "path": "/work/20260211-232328-2ade/fig3_transient.png" } ``` **output** ``` [image/png, 227814 bytes] /work/20260211-232328-2ade/fig3_transient.png — 1755x910 image/png, 227813 bytes ``` ### agent **The GIF is on your machine:** `...\20260211-232328-2ade\cyl_tr_Re100\cyl_tr_Re100_vorticity.gif` (10 MB, 149 frames, ~5 shedding cycles, spanwise vorticity, red/blue = counter-rotating vortices). **What was run:** `pimpleFoam`, transient, Re = 100, laminar. New 110k-cell O-grid keeping cells ≤ 0.07 D out to 8 D radius so the wake survives downstream. Impulsive start from uniform flow, with the inlet held at 5° for the first second to trip the instability (otherwise a perfectly symmetric mesh takes a very long time to break symmetry through round-off). Adaptive timestep at max Co = 0.9, dt ≈ 6.8e-4 s, 12.5 s physical time ≈ 20 shedding periods, 8 cores, ~35 min wall. **It validates:** | quantity | this run | published, Re = 100 | |---|---|---| | Strouhal number | **0.1653** | 0.164–0.167 | | mean Cd | **1.345** | 1.32–1.37 | | Cd amplitude | 0.0109 | 0.009–0.011 | | Cl amplitude | ±0.339 | 0.32–0.34 | St came from interpolated zero-crossings of Cl over t = 7.5–12.5 s (period 0.60480 ± 0.00008 s), not from an FFT — the 3.5 s record is too short for useful FFT resolution. `fig3_transient.png` shows the whole story: the instability growing exponentially from the kick, saturating around t ≈ 8 s, and Cd oscillating at exactly twice the shedding frequency (each shed vortex, either sign, adds drag). **Caveats, same as before:** laminar with no turbulence model — legitimate at Re = 100, where the real flow is genuinely 2D and laminar (3D instability only sets in near Re ≈ 190). Above that this setup would be reporting a 2D fiction. A pressure-field GIF of the same window is still rendering (~5 min); it'll appear at `cyl_tr_Re100/cyl_tr_Re100_p.gif`. There's also ~2 GB of frame data and reconstructed time directories in the case — say the word and I'll clear it, or leave it if you want to re-render at different zoom/colour limits. And if you want the higher-Re air case we discussed earlier, this mesh and setup carry straight over. ### you Okay, re-run the simulation, except instead of a cylinder make it an L shape. ## Reference Williamson, C. H. K. (1996). Vortex dynamics in the cylinder wake. Annual Review of Fluid Mechanics, 28, 477–539. ## 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.