--- title: "A hull, a friction line, and a form factor" url: "https://tryreynolds.com/studies/wigley-hull" description: "Given an STL and a towing speed, Reynolds noticed the file was not the shape the request described, corrected the reference area, and produced a viscous and form drag breakdown in under three minutes." --- **[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/wigley-hull. It lives at https://tryreynolds.com/studies/wigley-hull.md, and [tryreynolds.com/llms.txt](https://tryreynolds.com/llms.txt) indexes every one of them. # A hull, a friction line, and a form factor Given an STL and a towing speed, Reynolds noticed the file was not the shape the request described, corrected the reference area, and produced a viscous and form drag breakdown in under three minutes. RUN 09VALIDATIONMARINEAUGUST 202620260811-011037-e0c1 - **Asked**: A Wigley parabolic hull, 3 m long, towed at 1.36 m/s, which is Froude 0.25 on that length: drag, and how it compares with the standard friction line. - **Run**: simpleFoam, k-ω SST · 54,000 cells · 4 cores · under 3 minutes - **Result**: Form factor about 1.17 - **Conditions**: Re_L = 3.43 × 10⁶, Fr_L = 0.25 - **Friction**: C_f = 3.253 × 10⁻³ - **ITTC-57 line**: 3.647 × 10⁻³ at this Reynolds number - **Form factor**: C_t = 3.812 × 10⁻³, giving about 1.17 ![A Wigley parabolic hull form, capped flat at the waterline](https://tryreynolds.com/assets/wigley-geometry-DD0zLmoS.png) Figure 1 The hull as read from the supplied STL: a smooth parabolic form, capped flat at the waterline. ## It checked the geometry against the sentence The request described the file as the half-hull below the waterline. When Reynolds rendered the STL and looked at it, it was something else: a closed solid, the full-beam submerged hull, capped flat across the waterline plane. That distinction decides the answer. A friction coefficient is force divided by dynamic pressure and wetted area, and the flat cap at the waterline is not wetted: it is the plane the water surface sits on. Of 1.94 m² of surface in the file, 0.60 m² is that cap. Reynolds split the cap off and used the remaining 1.339 m² as the wetted skin. This is the class of error that survives review, because the number it produces looks entirely reasonable and nothing in the pipeline objects. ## The model, and what it buys It built a quarter domain, taking symmetry twice: once at the ship's own centreplane and once at the calm waterline. The second plane makes this a double-body model, the standard tool for isolating the viscous and form components of resistance from the wave-making component, and it is enormously cheap: 54,000 cells, four cores, converged in under three minutes. Mesh quality was confirmed before the solve rather than diagnosed after: 12 skewed faces out of 170,000, and four boundary layers reaching about 92% of target thickness on the hull. Residuals settled below 2 × 10⁻⁵ with forces steady to four significant figures. ## What the two numbers tell you together The friction coefficient comes out at 3.253 × 10⁻³, sitting about 11% under the ITTC-57 correlation. The total from the double-body solve, friction plus viscous pressure, is 3.812 × 10⁻³. The ratio of those two is the interesting output: a form factor of about 1.17, meaning the shape of the hull adds roughly 17% on top of what an equivalent flat plate of the same wetted area would suffer. That is a plausible figure for this hull, and it is precisely the quantity a resistance breakdown exists to produce. Naval architects use it to scale model tests to full size. ![Computed frictional resistance coefficient against the ITTC-57 correlation line](https://tryreynolds.com/assets/wigley-cf-DvRYHu65.png) Figure 2 Computed frictional resistance against the ITTC-57 correlation line across Reynolds number. ## 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. 17 messages, 83 tool calls ### you /work/geometry/wigley_hull_L3m.stl is a Wigley parabolic hull, 3 m long, 0.3 m beam, drafted 0.1875 m, in metres. It's the half-hull below the waterline. Tow it at 1.36 m/s, which is Froude 0.25 on length. I don't need a free surface for this one — do it as a double-body viscous calculation and give me the frictional resistance coefficient, then compare it against the ITTC-57 correlation line at that Reynolds number. Say clearly what you are and are not capturing by leaving the free surface out, because the published Wigley numbers include wave resistance and mine will not. Quick look. ### tool: bash `ls /work/geometry/; ls /work/.toolbox; ls /work/.toolbox/notes 2>/dev/null; np...` exit 0 **input** ``` { "cmd": "ls /work/geometry/; ls /work/.toolbox; ls /work/.toolbox/notes 2>/dev/null; nproc" } ``` **output** ``` exit_code: 0 ahmed_body_25deg.stl apc_sf_10x4.7_propeller.stl basic_finner_projectile.stl cyclist_rider_openfoam.stl golf_ball.stl nrel_phase6_blade.stl onera_m6_wing.stl suboff_bare_hull.stl tube_bundle_staggered.stl wigley_hull_L3m.stl 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 showcase.py study_run.py study_state.py bundle-layout.md openfoam-agent-architecture.md openfoam-field-notes.md 4 ``` ### tool: bash `python3 - <<'EOF'` exit 0 **input** ``` { "cmd": "python3 - <<'EOF'\nimport numpy as np\nfrom stl import mesh\nEOF\npip show numpy-stl 2>/dev/null | head -1\npython3 -c \"\nimport pyvista as pv\npv.OFF_SCREEN=True\nm = pv.read('/work/geometry/wigley_hull_L3m.stl')\nprint(m.bounds)\nprint(m.n_points, m.n_cells)\n\"" } ``` **output** ``` exit_code: 0 Traceback (most recent call last): File "", line 2, in ModuleNotFoundError: No module named 'stl' BoundsTuple(x_min = -1.5, x_max = 1.5, y_min = -0.15000000596046448, y_max = 0.15000000596046448, z_min = -0.1875, z_max = 0.0) 24201 48398 ``` ### tool: bash `sed -n '1,200p' /work/.toolbox/geometry_view.py` exit 0 **input** ``` { "cmd": "sed -n '1,200p' /work/.toolbox/geometry_view.py" } ``` **output** ``` exit_code: 0 #!/usr/bin/env python3 """Surface geometry -> pictures of it, plus the numbers that describe it. Meshing decisions are made against geometry nobody has looked at, and a surface that is 1000x too large, inside-out, or full of holes looks exactly like a good one from the shell. This draws it -- four fixed views, every facet edge visible -- and prints what is measurable about it. It attaches no verdicts: whether 40 open edges matter depends on where they are and what you are about to run. python3 geometry_view.py wing.stl python3 geometry_view.py constant/triSurface/ # every surface in a dir python3 geometry_view.py a.stl b.stl --per-part --out /work/case/renders python3 geometry_view.py wing.stl --check # numbers only, no render Reads anything VTK reads: .stl, .obj, .ply, .vtk, .vtp, .vtu. """ from __future__ import annotations import argparse import sys from pathlib import Path import numpy as np import pyvista as pv pv.OFF_SCREEN = True SUFFIXES = (".stl", ".obj", ".ply", ".vtk", ".vtp", ".vtu") VIEWS = (("iso", "isometric"), ("xy", "+z looking down"), ("xz", "+y"), ("yz", "+x")) EDGE_BUDGET = 200_000 """Above this many faces, every-edge rendering draws mud. Decimate and say so.""" COLOURS = ( "lightsteelblue", "salmon", "darkseagreen", "khaki", "plum", "lightcoral", "paleturquoise", "sandybrown", "thistl ``` ### tool: bash `sed -n '1,400p' /work/.toolbox/render.py` exit 0 **input** ``` { "cmd": "sed -n '1,400p' /work/.toolbox/render.py" } ``` **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 ``` ### tool: bash `cat /work/.toolbox/notes/openfoam-field-notes.md` exit 0 **input** ``` { "cmd": "cat /work/.toolbox/notes/openfoam-field-notes.md" } ``` **output** ``` exit_code: 0 # 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 grammar does exist in one authoritative place: the binaries in front of you. - `foamDictionary -expand ` resolves includes and variables. Good for reading; do not write the expanded form back, ``` ### tool: bash `sed -n '1,80p' /work/.toolbox/case_gen.py; echo ---; grep -n "def main\|add_ar...` exit 0 **input** ``` { "cmd": "sed -n '1,80p' /work/.toolbox/case_gen.py; echo ---; grep -n \"def main\\|add_argument\\|preset\\|external\" /work/.toolbox/case_gen.py | head -80" } ``` **output** ``` exit_code: 0 #!/usr/bin/env python3 r"""Complete, runnable OpenFOAM cases from a template name and a few numbers. Typing out blockMeshDict, the system and constant dictionaries and a 0/ directory by hand costs most of an hour per study, and the hour is not spent where the thinking is. The mistakes it produces are the dull ones, and they all cost a solver run to find: two cells in z so the "2D" case is quietly 3D and forty times slower; a frontAndBack patch declared `empty` in the mesh and `zeroGradient` in 0/U, which stops the solver on the first time step; a patch called `inlet` in the mesh and `Inlet` in the fields; a viscosity typed in for the Reynolds number somebody meant to run last week. So the shapes are parameterised instead. What comes out is a directory you can run blockMesh in, and every file it contains is one you can open and edit -- nothing here is a black box at run time, and a generated dictionary that is 90% of what you want is meant to be edited the other 10%. what it derives, and says it derived Give it a free-stream speed, a Reynolds number and a characteristic length and it solves nu = U*L/Re and writes that into transportProperties, then prints the three numbers it used. Give it --nu instead and it prints the Reynolds number that implies. The one that is not stated is the one that gets misremembered. ``` ### tool: bash `grep -n "def \|preset\|add_argument" /work/.toolbox/preflight.py /work/.toolbo...` exit 0 **input** ``` { "cmd": "grep -n \"def \\|preset\\|add_argument\" /work/.toolbox/preflight.py /work/.toolbox/cells_estimate.py /work/.toolbox/results.py | head -100" } ``` **output** ``` exit_code: 0 /work/.toolbox/preflight.py:106: def as_dict(self) -> dict[str, str]: /work/.toolbox/preflight.py:129:def worst_status(findings) -> str: /work/.toolbox/preflight.py:133:def count_phrase(number: int, noun: str, plural: str = "") -> str: /work/.toolbox/preflight.py:139:def escalate(current: str, candidate: str) -> str: /work/.toolbox/preflight.py:145:def summarise(findings) -> dict[str, int]: /work/.toolbox/preflight.py:192:def strip_comments(text: str) -> str: /work/.toolbox/preflight.py:196:def read_text(path: Path) -> str: /work/.toolbox/preflight.py:212:def block_body(text: str, keyword: str) -> str: /work/.toolbox/preflight.py:235:def block_entries(body: str) -> list[tuple[str, str]]: /work/.toolbox/preflight.py:266:def outer_text(body: str) -> str: /work/.toolbox/preflight.py:286:def entry_values(body: str) -> dict[str, str]: /work/.toolbox/preflight.py:297:def parse_control(text: str) -> dict[str, str]: /work/.toolbox/preflight.py:307:def as_float(value: Any) -> float | None: /work/.toolbox/preflight.py:314:def parse_boundary(text: str) -> list[dict[str, Any]]: /work/.toolbox/preflight.py:331:def parse_block_mesh_boundary(text: str) -> list[dict[str, Any]]: /work/.toolbox/preflight.py:377:def parse_boundary_field(text: str) -> dict[str, Any]: /work/.toolbox/preflight.py:408:def parse_dimensions(text: str) -> tuple[float, ...] | None: /work/.toolbox/preflig ``` ### tool: bash `mkdir -p /work/20260811-011037-e0c1` exit 0 **input** ``` { "cmd": "mkdir -p /work/20260811-011037-e0c1\ncd /work/20260811-011037-e0c1\npython3 /work/.toolbox/geometry_view.py /work/geometry/wigley_hull_L3m.stl --out /work/20260811-011037-e0c1/renders_geom\n" } ``` **output** ``` exit_code: 0 /work/geometry/wigley_hull_L3m.stl faces 48,398 points 24,201 bodies 1 bbox x [-1.5, 1.5] y [-0.15, 0.15] z [-0.1875, 0] extent 3 x 0.3 x 0.1875 (OpenFOAM reads these as metres) open edges 0 non-manifold edges 1 duplicate points 0 enclosed volume 0.0749929 surface area 1.93909 face area 2.34e-05 .. 0.00225 typical edge 0.00772 zero-area faces 0 /work/20260811-011037-e0c1/renders_geom/geometry.png ``` ### tool: bash `cd /work/20260811-011037-e0c1` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1\nmkdir -p case/constant/triSurface case/system case/0.orig\ncp /work/geometry/wigley_hull_L3m.stl case/constant/triSurface/hull.stl\nls case/constant/triSurface" } ``` **output** ``` exit_code: 0 [took 15s] hull.stl ``` ### tool: read_file `/work/20260811-011037-e0c1/renders_geom/geometry.png` **input** ``` { "path": "/work/20260811-011037-e0c1/renders_geom/geometry.png" } ``` **output** ``` [image/png, 42993 bytes] /work/20260811-011037-e0c1/renders_geom/geometry.png — 1400x1000 image/png, 42991 bytes ``` ### tool: write_file `/work/20260811-011037-e0c1/case/system/blockMeshDict` **input** ``` { "path": "/work/20260811-011037-e0c1/case/system/blockMeshDict", "content": "FoamFile\n{\n version 2.0;\n format ascii;\n class dictionary;\n object blockMeshDict;\n}\n\nscale 1;\n\n// Quarter-domain background mesh.\n// x: upstream 1.5L, downstream 3L of the L=3m hull (hull spans x=-1.5..1.5)\n// y: 0 (centreplane symmetry, hull already half-beam... actually full beam, y=0 is symmetry) to 1.5L side\n// z: -1.5L (bottom, far field) to 0 (waterline = double-body symmetry plane)\n\nxmin -4.5;\nxmax 10.5;\nymin 0;\nymax 4.5;\nzmin -4.5;\nzmax 0;\n\nnx 75;\nny 23;\nnz 23;\n\nvertices\n(\n ($xmin $ymin $zmin)\n ($xmax $ymin $zmin)\n ($xmax $ymax $zmin)\n ($xmin $ymax $zmin)\n ($xmin $ymin $zmax)\n ($xmax $ymin $zmax)\n ($xmax $ymax $zmax)\n ($xmin $ymax $zmax)\n);\n\nblocks\n(\n hex (0 1 2 3 4 5 6 7) ($nx $ny $nz) simpleGrading (1 1 1)\n);\n\nedges\... ``` **output** ``` wrote 1260 bytes to /work/20260811-011037-e0c1/case/system/blockMeshDict ``` ### tool: write_file `/work/20260811-011037-e0c1/case/system/blockMeshDict` **input** ``` { "path": "/work/20260811-011037-e0c1/case/system/blockMeshDict", "content": "FoamFile\n{\n version 2.0;\n format ascii;\n class dictionary;\n object blockMeshDict;\n}\n\nscale 1;\n\n// Quarter-domain background mesh.\n// x: upstream 1.5L, downstream 3L of the L=3m hull (hull spans x=-1.5..1.5)\n// y: 0 (centreplane, hull is full-beam so this is a true symmetry plane) to 1.5L side\n// z: -1.5L (bottom, far field) to 0 (waterline = double-body symmetry plane)\n\nxmin -4.5;\nxmax 10.5;\nymin 0;\nymax 4.5;\nzmin -4.5;\nzmax 0;\n\nnx 75;\nny 23;\nnz 23;\n\nvertices\n(\n ($xmin $ymin $zmin)\n ($xmax $ymin $zmin)\n ($xmax $ymax $zmin)\n ($xmin $ymax $zmin)\n ($xmin $ymin $zmax)\n ($xmax $ymin $zmax)\n ($xmax $ymax $zmax)\n ($xmin $ymax $zmax)\n);\n\nblocks\n(\n hex (0 1 2 3 4 5 6 7) ($nx $ny $nz) simpleGrading (1 1 1)\n);\n\nedges\n();\n\nboundary\n(\... ``` **output** ``` wrote 1230 bytes to /work/20260811-011037-e0c1/case/system/blockMeshDict ``` ### tool: bash `cd /work/20260811-011037-e0c1/case && blockMesh 2>&1 | tail -40` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case && blockMesh 2>&1 | tail -40" } ``` **output** ``` exit_code: 0 /*---------------------------------------------------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 2512 | | \\ / A nd | Website: www.openfoam.com | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ Build : _87ed40d2-20251219 OPENFOAM=2512 version=2512 Arch : "LSB;label=32;scalar=64" Exec : blockMesh Date : Aug 29 2026 Time : 17:14:20 Host : modal PID : 2944 I/O : uncollated Case : /work/20260811-011037-e0c1/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 FATAL ERROR: (openfoam-2512) cannot find file "/work/20260811-011037-e0c1/case/system/controlDict" From virtual Foam::autoPtr Foam::fileOperations::un ``` ### agent Need controlDict etc first. Let me write the full case set (controlDict, fvSchemes, fvSolution, snappyHexMeshDict, surfaceFeatureExtractDict, 0.orig fields, transportProperties, turbulenceProperties). ### tool: write_file `/work/20260811-011037-e0c1/case/system/controlDict` **input** ``` { "path": "/work/20260811-011037-e0c1/case/system/controlDict", "content": "FoamFile\n{\n version 2.0;\n format ascii;\n class dictionary;\n object controlDict;\n}\n\napplication simpleFoam;\n\nstartFrom latestTime;\nstartTime 0;\nstopAt endTime;\nendTime 1500;\n\ndeltaT 1;\nwriteControl timeStep;\nwriteInterval 250;\npurgeWrite 3;\n\nwriteFormat binary;\nwritePrecision 7;\nwriteCompression off;\ntimeFormat general;\ntimePrecision 6;\nrunTimeModifiable true;\n\nfunctions\n{\n forces\n {\n type forceCoeffs;\n libs (forces);\n writeControl timeStep;\n writeInterval 10;\n patches (hull);\n rho rhoInf;\n rhoInf 998.0;\n liquid yes;\n magUInf 1.36;\n lRef 3... ``` **output** ``` http_error (500): Internal Server Error ``` ### tool: write_file `/work/20260811-011037-e0c1/case/system/fvSchemes` **input** ``` { "path": "/work/20260811-011037-e0c1/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 cellLimited Gauss linear 1;\n}\n\ndivSchemes\n{\n default none;\n div(phi,U) bounded Gauss linearUpwindV grad(U);\n div(phi,k) bounded Gauss limitedLinear 1;\n div(phi,omega) bounded Gauss limitedLinear 1;\n div((nuEff*dev2(T(grad(U))))) Gauss linear;\n}\n\nlaplacianSchemes\n{\n default Gauss linear limited corrected 0.33;\n}\n\ninterpolationSchemes\n{\n default linear;\n}\n\nsnGradSchemes\n{\n default limited corrected 0.33;\n}\n\nwallDist\n{\n method meshWave;\n}\n" } ``` **output** ``` wrote 678 bytes to /work/20260811-011037-e0c1/case/system/fvSchemes ``` ### tool: write_file `/work/20260811-011037-e0c1/case/system/fvSolution` **input** ``` { "path": "/work/20260811-011037-e0c1/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 smoother GaussSeidel;\n tolerance 1e-8;\n relTol 0.05;\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\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 1.0;\n }\n equations\n {\n U 0.9;\n \"(k|omega)\" 0.9;\n... ``` **output** ``` wrote 770 bytes to /work/20260811-011037-e0c1/case/system/fvSolution ``` ### tool: write_file `/work/20260811-011037-e0c1/case/system/controlDict` **input** ``` { "path": "/work/20260811-011037-e0c1/case/system/controlDict", "content": "FoamFile\n{\n version 2.0;\n format ascii;\n class dictionary;\n object controlDict;\n}\n\napplication simpleFoam;\n\nstartFrom latestTime;\nstartTime 0;\nstopAt endTime;\nendTime 1500;\n\ndeltaT 1;\nwriteControl timeStep;\nwriteInterval 250;\npurgeWrite 3;\n\nwriteFormat binary;\nwritePrecision 7;\nwriteCompression off;\ntimeFormat general;\ntimePrecision 6;\nrunTimeModifiable true;\n\nfunctions\n{\n forces\n {\n type forceCoeffs;\n libs (forces);\n writeControl timeStep;\n writeInterval 10;\n patches (hull);\n rho rhoInf;\n rhoInf 998.0;\n liquid yes;\n magUInf 1.36;\n lRef 3... ``` **output** ``` wrote 1271 bytes to /work/20260811-011037-e0c1/case/system/controlDict ``` ### tool: write_file `/work/20260811-011037-e0c1/case/system/controlDict` **input** ``` { "path": "/work/20260811-011037-e0c1/case/system/controlDict", "content": "FoamFile\n{\n version 2.0;\n format ascii;\n class dictionary;\n object controlDict;\n}\n\napplication simpleFoam;\n\nstartFrom latestTime;\nstartTime 0;\nstopAt endTime;\nendTime 1500;\n\ndeltaT 1;\nwriteControl timeStep;\nwriteInterval 250;\npurgeWrite 3;\n\nwriteFormat binary;\nwritePrecision 7;\nwriteCompression off;\ntimeFormat general;\ntimePrecision 6;\nrunTimeModifiable true;\n\nfunctions\n{\n // Raw force/moment (pressure + viscous) on the modelled half of the wetted\n // hull. Coefficients are computed in post-processing, since the patch here\n // is only half the ship (y>0 side) under the y=0 symmetry plane and the\n // Aref slot in forceCoeffs would otherwise invite a factor-of-two mistake.\n hullForces\n... ``` **output** ``` wrote 1402 bytes to /work/20260811-011037-e0c1/case/system/controlDict ``` ### agent Now the transport/turbulence properties, 0.orig fields, snappyHexMeshDict, and surfaceFeatures. ### tool: write_file `/work/20260811-011037-e0c1/case/constant/transportProperties` **input** ``` { "path": "/work/20260811-011037-e0c1/case/constant/transportProperties", "content": "FoamFile\n{\n version 2.0;\n format ascii;\n class dictionary;\n object transportProperties;\n}\n\n// Fresh water at 15 degC, ITTC standard reference value.\ntransportModel Newtonian;\nnu [0 2 -1 0 0 0 0] 1.19e-06;\n" } ``` **output** ``` wrote 231 bytes to /work/20260811-011037-e0c1/case/constant/transportProperties ``` ### tool: write_file `/work/20260811-011037-e0c1/case/constant/turbulenceProperties` **input** ``` { "path": "/work/20260811-011037-e0c1/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/20260811-011037-e0c1/case/constant/turbulenceProperties ``` ### tool: bash `mkdir -p /work/20260811-011037-e0c1/case/0.orig` exit 0 **input** ``` { "cmd": "mkdir -p /work/20260811-011037-e0c1/case/0.orig" } ``` **output** ``` exit_code: 0 ``` ### tool: bash `head -3 /work/20260811-011037-e0c1/case/constant/triSurface/hull.stl; grep -c ...` exit 1 **input** ``` { "cmd": "head -3 /work/20260811-011037-e0c1/case/constant/triSurface/hull.stl; grep -c \"^solid\" /work/20260811-011037-e0c1/case/constant/triSurface/hull.stl" } ``` **output** ``` exit_code: 1 Wigley parabolic hull L=3.0 B=0.3 T=0.1875 m �[���C=��@�{��@�{�����8��<����;�����@�{�����8��<�����<��p�;��;/�<����<�{�����8��<�{��X0M9��9�_�U&1; surfaceFeatures -help 2>&1 |...` exit 0 **input** ``` { "cmd": "which surfaceFeatures surfaceFeatureExtract 2>&1; surfaceFeatures -help 2>&1 | head -20" } ``` **output** ``` exit_code: 0 /usr/lib/openfoam/openfoam2512/platforms/linux64GccDPInt32Opt/bin/surfaceFeatureExtract bash: line 4: surfaceFeatures: command not found ``` ### tool: bash `find /usr/lib/openfoam -iname "*surfaceFeatureExtractDict*" 2>/dev/null | head...` exit 0 **input** ``` { "cmd": "find /usr/lib/openfoam -iname \"*surfaceFeatureExtractDict*\" 2>/dev/null | head; find /usr/lib/openfoam -iname \"*surfaceFeatures*\" -path \"*tutorials*\" 2>/dev/null | head\nfoamSearch=$(find /usr/lib/openfoam -iname \"surfaceFeatureExtractDict\" | head -1)\ncat \"$foamSearch\" 2>/dev/null | head -60" } ``` **output** ``` exit_code: 0 /usr/lib/openfoam/openfoam2512/applications/test/zoneDistribute/case1/system/surfaceFeatureExtractDict /usr/lib/openfoam/openfoam2512/etc/caseDicts/annotated/surfaceFeatureExtractDict /usr/lib/openfoam/openfoam2512/etc/caseDicts/surface/surfaceFeatureExtractDict.cfg /usr/lib/openfoam/openfoam2512/etc/templates/closedVolume/system/surfaceFeatureExtractDict /usr/lib/openfoam/openfoam2512/etc/templates/closedVolumeRotating/system/surfaceFeatureExtractDict /usr/lib/openfoam/openfoam2512/etc/templates/compressibleInflowOutflow/system/surfaceFeatureExtractDict /usr/lib/openfoam/openfoam2512/etc/templates/inflowOutflow/system/surfaceFeatureExtractDict /usr/lib/openfoam/openfoam2512/etc/templates/inflowOutflowRotating/system/surfaceFeatureExtractDict /usr/lib/openfoam/openfoam2512/tutorials/compressible/rhoPimpleFoam/RAS/annularThermalMixer/system/surfaceFeatureExtractDict /usr/lib/openfoam/openfoam2512/tutorials/compressible/rhoPimpleFoam/RAS/annularThermalMixer/system/surfaceFeatureExtractDictDefaults /*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: v2512 | | \\ / A nd | Website: www.openfoam.co ``` ### tool: write_file `/work/20260811-011037-e0c1/case/system/surfaceFeatureExtractDict` **input** ``` { "path": "/work/20260811-011037-e0c1/case/system/surfaceFeatureExtractDict", "content": "FoamFile\n{\n version 2.0;\n format ascii;\n class dictionary;\n object surfaceFeatureExtractDict;\n}\n\nhull.stl\n{\n extractionMethod extractFromSurface;\n includedAngle 150;\n writeObj no;\n}\n" } ``` **output** ``` wrote 223 bytes to /work/20260811-011037-e0c1/case/system/surfaceFeatureExtractDict ``` ### tool: bash `cd /work/20260811-011037-e0c1/case` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case\nrm -f system/surfaceFeaturesDict\nblockMesh > log.blockMesh 2>&1; tail -25 log.blockMesh\ncheckMesh -latestTime > log.checkMesh.background 2>&1; tail -30 log.checkMesh.background" } ``` **output** ``` exit_code: 0 k : 0.1956522 .. 0.1956522 No patch pairs to merge Writing polyMesh with 0 cellZones ---------------- Mesh Information ---------------- boundingBox: (-4.5 0 -4.5) (10.5 4.5 0) nPoints: 43776 nCells: 39675 nFaces: 123004 nInternalFaces: 115046 ---------------- Patches ---------------- patch 0 (start: 115046 size: 529) name: inlet patch 1 (start: 115575 size: 529) name: outlet patch 2 (start: 116104 size: 1725) name: ySymmetry patch 3 (start: 117829 size: 1725) name: yFar patch 4 (start: 119554 size: 1725) name: zSymmetry patch 5 (start: 121279 size: 1725) name: zFar End 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 (-4.5 0 -4.5) (10.5 4.5 0) Mesh has 3 geometric (non-empty/wedge) directions (1 1 1) Mesh has 3 solution (non-empty) directions (1 1 1) Boundary openness (-6.458423e-18 -1.086535e-16 -2.087255e-17) OK. Max cell openness = 2.719018e-16 OK. Max aspect ratio = 1.022222 OK. Minimum face area = 0.03827977. Maximum face area = 0.03913043. Face area magnitudes OK. Min volume = 0.007655955. Max volume = 0.007655955. Total volume = 303.75. Cell volumes OK. Mesh non-orthogonal ``` ### agent Background mesh good. Now run surfaceFeatureExtract then snappyHexMesh in parallel (4 cores). ### tool: bash `cd /work/20260811-011037-e0c1/case` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case\nsurfaceFeatureExtract > log.surfaceFeatureExtract 2>&1; tail -20 log.surfaceFeatureExtract\nls constant/triSurface/" } ``` **output** ``` exit_code: 0 of which convex : 1 concave : 1 mixed : 4 non-feature : 713 edges : 723 of which external edges : 2 internal edges : 716 flat edges : 0 open edges : 2 multiply connected : 3 Writing extendedFeatureEdgeMesh to "/work/20260811-011037-e0c1/case/constant/extendedFeatureEdgeMesh/hull.extendedFeatureEdgeMesh" Writing featureEdgeMesh to "/work/20260811-011037-e0c1/case/constant/triSurface/hull.eMesh" ExecutionTime = 0.08 s ClockTime = 0 s End hull.eMesh hull.stl ``` ### agent Now decompose and run snappyHexMesh in parallel with 4 cores. ### tool: write_file `/work/20260811-011037-e0c1/case/system/decomposeParDict` **input** ``` { "path": "/work/20260811-011037-e0c1/case/system/decomposeParDict", "content": "FoamFile\n{\n version 2.0;\n format ascii;\n class dictionary;\n object decomposeParDict;\n}\n\nnumberOfSubdomains 4;\n\nmethod hierarchical;\n\nhierarchicalCoeffs\n{\n n (2 2 1);\n delta 0.001;\n order xyz;\n}\n" } ``` **output** ``` wrote 246 bytes to /work/20260811-011037-e0c1/case/system/decomposeParDict ``` ### tool: job_start `cd /work/20260811-011037-e0c1/case && decomposePar -force > log.decompose1 2>&...` **input** ``` { "name": "snappy", "cmd": "cd /work/20260811-011037-e0c1/case && decomposePar -force > log.decompose1 2>&1 && mpirun -np 4 snappyHexMesh -parallel -overwrite > log.snappy 2>&1 && echo SNAPPY_DONE" } ``` **output** ``` started job eb3d53cb-3811-46ae-8ab2-db87f8cddd45 (snappy) ``` ### tool: job_check `job_id=eb3d53cb-3811-46ae-8ab2-db87f8cddd45 wait_s=280` **input** ``` { "job_id": "eb3d53cb-3811-46ae-8ab2-db87f8cddd45", "wait_s": 280 } ``` **output** ``` job eb3d53cb-3811-46ae-8ab2-db87f8cddd45 name=snappy status=exited exit_code=1 end_reason=failed log_size=0 ran_for=4s log: bytes 0–0, eof=True ``` ### tool: bash `cd /work/20260811-011037-e0c1/case; tail -40 log.decompose1 2>/dev/null; echo ...` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case; tail -40 log.decompose1 2>/dev/null; echo ----; tail -40 log.snappy 2>/dev/null" } ``` **output** ``` exit_code: 0 Number of points = 11581 Number of faces shared with processor 0 = 274 Number of faces shared with processor 3 = 906 Number of processor patches = 2 Number of processor faces = 1180 Number of boundary faces = 1996 Processor 2 Number of cells = 9919 Number of points = 11581 Number of faces shared with processor 0 = 906 Number of faces shared with processor 3 = 274 Number of processor patches = 2 Number of processor faces = 1180 Number of boundary faces = 1996 Processor 3 Number of cells = 9919 Number of points = 11587 Number of faces shared with processor 0 = 25 Number of faces shared with processor 1 = 906 Number of faces shared with processor 2 = 274 Number of processor patches = 3 Number of processor faces = 1205 Number of boundary faces = 1983 Number of processor faces = 2385 Max number of cells = 9919 (0.002520479% above average 9918.75) Max number of processor patches = 3 (20% above average 2.5) Max number of faces between processors = 1205 (1.048218% above average 1192.5) Time = 0 Processor 0: field transfer Processor 1: field transfer Processor 2: field transfer Processor 3: field transfer End ---- [3] For refinement mode distance : Refinement should be specified in order of increasing distance (and decreasing refinement level). Distance:0.1 refinementLevel:2 [3] [3] ``` ### agent Need levels in order of increasing distance from far to near i.e largest distance first with lowest level. ### tool: bash `cd /work/20260811-011037-e0c1/case` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case\nsed -i 's/levels ((0.3 1) (0.1 2));/levels ((0.1 2) (0.3 1));/' system/snappyHexMeshDict\ngrep -A3 refinementRegions system/snappyHexMeshDict" } ``` **output** ``` exit_code: 0 refinementRegions { hull { ``` ### tool: job_start `cd /work/20260811-011037-e0c1/case && mpirun -np 4 snappyHexMesh -parallel -ov...` **input** ``` { "name": "snappy2", "cmd": "cd /work/20260811-011037-e0c1/case && mpirun -np 4 snappyHexMesh -parallel -overwrite > log.snappy 2>&1 && echo SNAPPY_DONE" } ``` **output** ``` started job 4534f81b-ce0f-4667-a1cf-c51d6a54b5ac (snappy2) ``` ### tool: job_check `job_id=4534f81b-ce0f-4667-a1cf-c51d6a54b5ac wait_s=280` **input** ``` { "job_id": "4534f81b-ce0f-4667-a1cf-c51d6a54b5ac", "wait_s": 280 } ``` **output** ``` job 4534f81b-ce0f-4667-a1cf-c51d6a54b5ac name=snappy2 status=exited exit_code=1 end_reason=failed log_size=0 ran_for=7s log: bytes 0–0, eof=True ``` ### tool: bash `cd /work/20260811-011037-e0c1/case; tail -60 log.snappy` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case; tail -60 log.snappy" } ``` **output** ``` exit_code: 0 [2] [2] [2] file: stream/addLayersControls at line 0. [2] [2] From bool Foam::dictionary::readEntry(const Foam::word&, T&, Foam::keyType::option, Foam::IOobjectOption::readOption) const [with T = double] [2] in file ./src/OpenFOAM/lnInclude/dictionaryTemplates.C at line 327. [2] FOAM parallel run exiting [2] [3] [3] [3] --> FOAM FATAL IO ERROR: (openfoam-2512) [3] Entry 'minMedialAxisAngle' not found in dictionary "stream/addLayersControls" [3] [3] [3] file: stream/addLayersControls at line 0. [3] [3] From bool Foam::dictionary::readEntry(const Foam::word&, T&, Foam::keyType::option, Foam::IOobjectOption::readOption) const [with T = double] [3] in file ./src/OpenFOAM/lnInclude/dictionaryTemplates.C at line 327. [3] FOAM parallel run exiting [3] [1] [1] [1] --> FOAM FATAL IO ERROR: (openfoam-2512) [1] Entry 'minMedialAxisAngle' not found in dictionary "stream/addLayersControls" [1] [1] [1] file: stream/addLayersControls at line Selecting externalDisplacementMeshMover displacementMedialAxis 0. [1] [1] From bool Foam::dictionary::readEntry(const Foam::word&, T&, Foam::keyType::option, Foam::IOobjectOption::readOption) const [with T = double] [1] in file ./src/OpenFOAM/lnInclude/dictionaryTemplates.C at line 327. [1] FOAM parallel run exiting [1] -------------------------------------------------------------------------- MPI_A ``` ### agent I had a typo: `minMedianAxisAngle` should be `minMedialAxisAngle`. ### tool: bash `cd /work/20260811-011037-e0c1/case` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case\nsed -i 's/minMedianAxisAngle/minMedialAxisAngle/' system/snappyHexMeshDict\ngrep -n MedialAxis system/snappyHexMeshDict" } ``` **output** ``` exit_code: 0 95: minMedialAxisAngle 90; ``` ### tool: bash `cd /work/20260811-011037-e0c1/case` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case\nls processor0/constant/polyMesh/ 2>/dev/null\ncat processor0/constant/polyMesh/owner 2>/dev/null | head -20" } ``` **output** ``` exit_code: 0 boundary cellLevel cellZones faceZones faces level0Edge neighbour owner pointLevel pointZones points surfaceIndex /*--------------------------------*- 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 binary; arch "LSB;label=32;scalar=64"; note "nPoints:16373 nCells:12552 nFaces:41233 nInternalFaces:36689"; class labelList; location "constant/polyMesh"; object owner; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // ``` ### agent Snapped mesh exists. Let's rerun with only addLayers stage. ### tool: bash `cd /work/20260811-011037-e0c1/case` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case\nsed -i 's/^castellatedMesh true;/castellatedMesh false;/;s/^snap true;/snap false;/' system/snappyHexMeshDict\ngrep -n \"^castellatedMesh\\|^snap \\|^addLayers\" system/snappyHexMeshDict" } ``` **output** ``` exit_code: 0 9:castellatedMesh false; 10:snap false; 11:addLayers true; 22:castellatedMeshControls 70:addLayersControls ``` ### tool: job_start `cd /work/20260811-011037-e0c1/case && mpirun -np 4 snappyHexMesh -parallel -ov...` **input** ``` { "name": "snappy3", "cmd": "cd /work/20260811-011037-e0c1/case && mpirun -np 4 snappyHexMesh -parallel -overwrite > log.snappy_layers 2>&1 && echo SNAPPY_DONE" } ``` **output** ``` started job 12b15003-049e-4111-bb1f-baceb78e9e44 (snappy3) ``` ### tool: job_check `job_id=12b15003-049e-4111-bb1f-baceb78e9e44 wait_s=280` **input** ``` { "job_id": "12b15003-049e-4111-bb1f-baceb78e9e44", "wait_s": 280 } ``` **output** ``` job 12b15003-049e-4111-bb1f-baceb78e9e44 name=snappy3 status=exited exit_code=0 end_reason=completed log_size=12 ran_for=3s log: bytes 0–12, eof=True SNAPPY_DONE ``` ### tool: bash `cd /work/20260811-011037-e0c1/case; tail -100 log.snappy_layers` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case; tail -100 log.snappy_layers" } ``` **output** ``` exit_code: 0 Determining displacement for added points according to pointNormal ... Detected 0 points with point normal pointing through faces. Reset displacement at 0 points to average of surrounding points. displacementMedialAxis : Smoothing using Medial Axis ... displacementMedialAxis : Reducing layer thickness at 0 nodes where thickness to medial axis distance is large displacementMedialAxis : Removing isolated regions ... - if partially extruded faces make angle < 75 - if exclusively surrounded by non-extruded faces displacementMedialAxis : Number of isolated points extrusion stopped : 0 fieldSmoother : Smoothing field ... Iteration 0 residual 0.0001755837 displacementMedialAxis : Moving mesh ... displacementMedialAxis : Iteration 0 Moving mesh using displacement scaling : min:1 max:1 Checking faces in error : non-orthogonality > 65 degrees : 0 faces with face pyramid volume < 1e-13 : 0 faces with face-decomposition tet quality < 1e-09 : 2 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 : ``` ### agent Mesh built: ~54k cells, 4 layers achieving 91.8% of target thickness on hull. Let's reconstruct and run checkMesh. ### tool: bash `cd /work/20260811-011037-e0c1/case` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case\nreconstructParMesh -constant -latestTime > log.reconstructParMesh 2>&1; tail -20 log.reconstructParMesh\ncheckMesh > log.checkMesh 2>&1; tail -80 log.checkMesh" } ``` **output** ``` exit_code: 0 boundaryProcAddressing Processor 2 Read processor mesh: "case/processor2" Writing addressing : "case/processor2/constant/polyMesh" pointProcAddressing faceProcAddressing cellProcAddressing boundaryProcAddressing Processor 3 Read processor mesh: "case/processor3" Writing addressing : "case/processor3/constant/polyMesh" pointProcAddressing faceProcAddressing cellProcAddressing boundaryProcAddressing End points: 62012 faces: 169916 internal faces: 158274 cells: 54114 faces per cell: 6.064789 boundary patches: 7 point zones: 1 face zones: 0 cell zones: 0 Overall number of cells of each type: hexahedra: 51937 prisms: 368 wedges: 0 pyramids: 0 tet wedges: 0 tetrahedra: 0 polyhedra: 1809 Breakdown of polyhedra by number of faces: faces number of cells 4 44 5 52 6 463 7 354 8 46 9 538 10 4 12 278 15 30 Checking topology... Boundary definition OK. Cell to face addressing OK. Point usage OK. Upper triangular ordering OK. Face vertices OK. Number of regions: 1 (OK). Checking patch topology for multiply connected surfaces... ``` ### tool: bash `cd /work/20260811-011037-e0c1/case` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case\ntouch case.foam 2>/dev/null\npython3 /work/.toolbox/render.py /work/20260811-011037-e0c1/case --scene mesh --normal y --out /work/20260811-011037-e0c1/renders 2>&1 | tail -20\npython3 /work/.toolbox/render.py /work/20260811-011037-e0c1/case --scene mesh --normal z --out /work/20260811-011037-e0c1/renders 2>&1 | tail -20\npython3 /work/.toolbox/render.py /work/20260811-011037-e0c1/case --scene mesh --normal x --out /work/20260811-011037-e0c1/renders 2>&1 | tail -20\n" } ``` **output** ``` exit_code: 0 time 0 (available: 0) cells 54,114 points 62,012 /work/20260811-011037-e0c1/renders/mesh_y.png time 0 (available: 0) cells 54,114 points 62,012 /work/20260811-011037-e0c1/renders/mesh_z.png time 0 (available: 0) cells 54,114 points 62,012 /work/20260811-011037-e0c1/renders/mesh_x.png ``` ### tool: read_file `/work/20260811-011037-e0c1/renders/mesh_y.png` **input** ``` { "path": "/work/20260811-011037-e0c1/renders/mesh_y.png" } ``` **output** ``` [image/png, 93324 bytes] /work/20260811-011037-e0c1/renders/mesh_y.png — 1100x800 image/png, 93323 bytes ``` ### tool: read_file `/work/20260811-011037-e0c1/renders/mesh_z.png` **input** ``` { "path": "/work/20260811-011037-e0c1/renders/mesh_z.png" } ``` **output** ``` [image/png, 86904 bytes] /work/20260811-011037-e0c1/renders/mesh_z.png — 1100x800 image/png, 86903 bytes ``` ### tool: write_file `/work/20260811-011037-e0c1/render_hull_mesh.py` **input** ``` { "path": "/work/20260811-011037-e0c1/render_hull_mesh.py", "content": "import pyvista as pv\nimport numpy as np\npv.OFF_SCREEN = True\n\nreader = pv.OpenFOAMReader(\"/work/20260811-011037-e0c1/case/case.foam\")\nreader.set_active_time_value(0.0)\nblock = reader.read()\nmesh = block[\"internalMesh\"] if isinstance(block, pv.MultiBlock) else block\n\n# z-normal slice at mid-draft (through the hull cross-section), close-up near hull\ncut_z = mesh.slice(normal=(0,0,1), origin=(0,0,-0.09))\np = pv.Plotter(off_screen=True, window_size=(1300,900))\np.add_mesh(cut_z, color=\"white\", show_edges=True, edge_color=\"black\", line_width=0.5)\np.view_xy()\np.enable_parallel_projection()\np.reset_camera(bounds=(-3,4.5,0,2.0,-1,1))\np.add_text(\"z-normal slice at z=-0.09 (mid-draft), close-up near hull\", font_size=10)\np.screenshot(\"/work/20260811-011037-e0c1/renders/mesh_z_hull_closeup.png\")\n... ``` **output** ``` wrote 1800 bytes to /work/20260811-011037-e0c1/render_hull_mesh.py ``` ### tool: bash `cd /work/20260811-011037-e0c1 && python3 render_hull_mesh.py 2>&1 | tail -30` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1 && python3 render_hull_mesh.py 2>&1 | tail -30" } ``` **output** ``` exit_code: 0 done ``` ### tool: read_file `/work/20260811-011037-e0c1/renders/mesh_z_hull_closeup.png` **input** ``` { "path": "/work/20260811-011037-e0c1/renders/mesh_z_hull_closeup.png" } ``` **output** ``` [image/png, 187905 bytes] /work/20260811-011037-e0c1/renders/mesh_z_hull_closeup.png — 1300x900 image/png, 187905 bytes ``` ### tool: read_file `/work/20260811-011037-e0c1/renders/mesh_y_hull_closeup.png` **input** ``` { "path": "/work/20260811-011037-e0c1/renders/mesh_y_hull_closeup.png" } ``` **output** ``` [image/png, 162072 bytes] /work/20260811-011037-e0c1/renders/mesh_y_hull_closeup.png — 1300x900 image/png, 162072 bytes ``` ### tool: bash `cd /work/20260811-011037-e0c1/case && python3 /work/.toolbox/mesh_digest.py lo...` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case && python3 /work/.toolbox/mesh_digest.py log.checkMesh 2>&1 | tail -60" } ``` **output** ``` exit_code: 0 # checkMesh ## counts points 62,012 faces 169,916 internal faces 158,274 cells 54,114 boundary patches 7 hexahedra 51,937 prisms 368 wedges 0 pyramids 0 tet wedges 0 tetrahedra 0 polyhedra 1,809 ## metrics non-orthogonality max / avg 39.7516 / 4.872313 max skewness 4.54169 max aspect ratio 11.96964 max cell openness 3.576652e-16 min / max face area 1.836419e-05 / 0.04095795 min / max cell volume 1.197547e-07 / 0.007993561 domain bounding box: (-4.5 0 -4.5) to (10.5 4.5 0) ## lines checkMesh flagged with *** Max skewness = 4.54169, 12 highly skew faces detected which may impair the quality of the results ``` ### tool: bash `cd /work/20260811-011037-e0c1/case` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case\ncp -r 0.orig 0\nrm -rf processor0 processor1 processor2 processor3\ndecomposePar -force > log.decompose2 2>&1; tail -20 log.decompose2" } ``` **output** ``` exit_code: 0 Number of faces shared with processor 1 = 1131 Number of faces shared with processor 2 = 299 Number of processor patches = 2 Number of processor faces = 1430 Number of boundary faces = 2538 Number of processor faces = 2770 Max number of cells = 13529 (0.003695901% above average 13528.5) Max number of processor patches = 3 (20% above average 2.5) Max number of faces between processors = 1548 (11.76895% above average 1385) Time = 0 Processor 0: field transfer Processor 1: field transfer Processor 2: field transfer Processor 3: field transfer End ``` ### agent Now do a quick 1-iteration probe to catch setup errors before committing to the full solve. ### tool: bash `cd /work/20260811-011037-e0c1/case` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case\ncp system/controlDict system/controlDict.bak\nsed -i 's/endTime 1500;/endTime 1;/' system/controlDict\nmpirun -np 4 simpleFoam -parallel > log.probe 2>&1\ntail -60 log.probe\nmv system/controlDict.bak system/controlDict" } ``` **output** ``` exit_code: 0 streamLine subtract surfaceDistance surfaceFieldValue surfaceInterpolate surfaces syncObjects systemCall thermoCoupleProbes timeActivatedFileUpdate timeInfo turbulenceFields valueAverage viewFactorHeatFlux volFieldValue vorticity vtkWrite wallBoundedStreamLine wallHeatFlux wallShearStress writeCellCentres writeCellVolumes writeDictionary writeObjects yPlus zeroGradient ) From static Foam::autoPtr Foam::functionObject::New(const Foam::word&, const Foam::Time&, const Foam::dictionary&) in file db/functionObjects/functionObject/functionObject.C at line 129. --> loading function object 'residuals' Time = 1 smoothSolver: Solving for Ux, Initial residual = 1, Final residual = 0.08725905, No Iterations 10 smoothSolver: Solving for Uy, Initial residual = 1, Final residual = 0.09037886, No Iterations 10 smoothSolver: Solving for Uz, Initial residual = 1, Final residual = 0.06930449, No Iterations 11 GAMG: Solving for p, Initial residual = 1, Final residual = 0.04045245, No Iterations 7 GAMG: Solving for p, Initial residual = 0.09772337, Final residual = 0.002758418, No Iterations 2 time step continuity errors : sum local = 6.080129e-06, global = -3.199369e-07, cumulative = -3.199369e-07 smoothSolver: Solving for omega, Initial residual = 0.9999855, Final residual = 0.005580404, No Iterations 1 bounding omega, min: -230.2439 max: 692 ``` ### tool: bash `cd /work/20260811-011037-e0c1/case; grep -n "FATAL\|Unknown function\errorFoam...` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case; grep -n \"FATAL\\|Unknown function\\errorFoam\\|yPlus\" log.probe | head -30" } ``` **output** ``` exit_code: 0 215:yPlus ``` ### tool: bash `cd /work/20260811-011037-e0c1/case; sed -n '1,230p' log.probe` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case; sed -n '1,230p' log.probe" } ``` **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 : simpleFoam -parallel Date : Aug 29 2026 Time : 17:22:16 Host : modal PID : 20339 I/O : uncollated Case : /__modal/volumes/vo-wvmvogItm3bZa84GOtUrFp/20260811-011037-e0c1/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) allowSystemOperations : ``` ### tool: bash `cd /work/20260811-011037-e0c1/case` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case\npython3 - <<'EOF'\nimport re\np = \"system/controlDict\"\ns = open(p).read()\ns2 = re.sub(r\"\\n residuals\\n \\{[^}]*\\}\\n\", \"\\n\", s)\nopen(p,\"w\").write(s2)\nEOF\ngrep -n \"residuals\\|yPlus\\|hullForces\" system/controlDict" } ``` **output** ``` exit_code: 0 34: hullForces 46: yPlus 48: type yPlus; ``` ### agent Good. Now reset the run (remove the probe's time-1 result) and launch the real steady solve. ### tool: bash `cd /work/20260811-011037-e0c1/case` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case\nfor d in processor0 processor1 processor2 processor3; do rm -rf $d/1; done\nrm -rf postProcessing\ncat system/controlDict | grep -A2 endTime\n" } ``` **output** ``` exit_code: 0 stopAt endTime; endTime 1500; deltaT 1; ``` ### tool: job_start `cd /work/20260811-011037-e0c1/case && mpirun -np 4 simpleFoam -parallel > log....` **input** ``` { "name": "simpleFoam_wigley", "cmd": "cd /work/20260811-011037-e0c1/case && mpirun -np 4 simpleFoam -parallel > log.simpleFoam 2>&1 && echo SOLVE_DONE" } ``` **output** ``` started job 48a0c34c-6341-4313-b6b3-bee1e110b0e5 (simpleFoam_wigley) ``` ### tool: job_check `job_id=48a0c34c-6341-4313-b6b3-bee1e110b0e5 wait_s=280` **input** ``` { "job_id": "48a0c34c-6341-4313-b6b3-bee1e110b0e5", "wait_s": 280 } ``` **output** ``` job 48a0c34c-6341-4313-b6b3-bee1e110b0e5 name=simpleFoam_wigley status=exited exit_code=0 end_reason=completed log_size=11 ran_for=2.4min [waited 137s] log: bytes 0–11, eof=True SOLVE_DONE ``` ### agent Solve finished in under 3 minutes. Let's check convergence. ### tool: bash `cd /work/20260811-011037-e0c1/case` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case\ntail -60 log.simpleFoam\necho ----\ngrep -n \"^Time = \" log.simpleFoam | tail -5\npython3 /work/.toolbox/log_digest.py log.simpleFoam 2>&1 | tail -60" } ``` **output** ``` exit_code: 0 forces hullForces write: Sum of forces Total : (2.355903 13.63507 -10.36627) Pressure : (0.3454296 13.59434 -10.34541) Viscous : (2.010473 0.04073352 -0.02085935) Sum of moments Total : (0.6170677 -0.5116472 1.153133) Pressure : (0.6144432 -0.2140717 1.369545) Viscous : (0.002624438 -0.2975756 -0.2164125) Time = 1499 smoothSolver: Solving for Ux, Initial residual = 1.724908e-06, Final residual = 1.349559e-07, No Iterations 2 smoothSolver: Solving for Uy, Initial residual = 1.106232e-05, Final residual = 5.264911e-07, No Iterations 3 smoothSolver: Solving for Uz, Initial residual = 7.470932e-06, Final residual = 6.74529e-07, No Iterations 2 GAMG: Solving for p, Initial residual = 4.5026e-06, Final residual = 1.606135e-07, No Iterations 2 GAMG: Solving for p, Initial residual = 3.604276e-07, Final residual = 1.67955e-08, No Iterations 4 time step continuity errors : sum local = 1.580912e-10, global = -8.185239e-12, cumulative = 2.118777e-07 smoothSolver: Solving for omega, Initial residual = 1.012533e-05, Final residual = 6.947086e-07, No Iterations 2 smoothSolver: Solving for k, Initial residual = 1.680393e-05, Final residual = 1.037089e-06, No Iterations 3 ExecutionTime = 124.15 s ClockTime = 139 s forces hullForces write: Sum of forces Total : (2.355901 13.63506 -10.36627) ``` ### tool: bash `python3 - <<'EOF'` exit 0 **input** ``` { "cmd": "python3 - <<'EOF'\nimport numpy as np\nimport pyvista as pv\npv.OFF_SCREEN=True\nm = pv.read('/work/geometry/wigley_hull_L3m.stl')\nm = m.compute_normals(cell_normals=True, point_normals=False, auto_orient_normals=True)\nnormals = np.asarray(m.cell_data['Normals'])\nareas = np.asarray(m.compute_cell_sizes(length=False, area=True, volume=False).cell_data['Area'])\n# cap faces: normal nearly +-z and located at z=0\ncenters = np.asarray(m.cell_centers().points)\nis_cap = (np.abs(centers[:,2]) < 1e-6) & (np.abs(normals[:,2])>0.99)\ncap_area = areas[is_cap].sum()\nskin_area = areas[~is_cap].sum()\nprint(\"total area\", areas.sum())\nprint(\"cap(waterplane) area (both sides, full beam)\", cap_area)\nprint(\"skin (wetted hull) area, full beam, both sides\", skin_area)\nprint(\"skin area, one side (y>0), i.e. what our half-model should have\", skin_area/2)\nEOF" } ``` **output** ``` exit_code: 0 total area 1.939089926938182 cap(waterplane) area (both sides, full beam) 0.5999850008853518 skin (wetted hull) area, full beam, both sides 1.3391049260528305 skin area, one side (y>0), i.e. what our half-model should have 0.6695524630264152 ``` ### tool: bash `cd /work/20260811-011037-e0c1/case` exit 1 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case\npython3 - <<'EOF'\nimport pyvista as pv\npv.OFF_SCREEN=True\nreader = pv.OpenFOAMReader(\"case.foam\")\nreader.set_active_time_value(1500.0)\nreader.cell_to_point_creation=False\nreader.enable_patch_array(\"hull\")\nblock = reader.read()\nprint(block.keys())\nbm = block[\"boundary\"]\nprint(bm.keys() if hasattr(bm,'keys') else bm)\nhull = bm[\"hull\"]\nprint(hull)\nareas = hull.compute_cell_sizes(length=False, area=True, volume=False).cell_data[\"Area\"]\nprint(\"hull patch area (simulated, y>0 half):\", areas.sum())\nEOF" } ``` **output** ``` exit_code: 1 Traceback (most recent call last): File "", line 4, in File "/usr/local/lib/python3.12/dist-packages/pyvista/core/utilities/reader.py", line 959, in set_active_time_value raise ValueError(msg) ValueError: Not a valid time 1500.0 from available time values: [0.0] ``` ### tool: bash `cd /work/20260811-011037-e0c1/case` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case\nreconstructPar -latestTime > log.reconstructPar 2>&1; tail -20 log.reconstructPar\nls" } ``` **output** ``` exit_code: 0 Reconstructing volVectorFields U Reconstructing surfaceScalarFields phi Reconstructing point fields No point fields No lagrangian fields No finite-area fields End 0 0.orig 1500 case.foam constant log.blockMesh log.checkMesh log.checkMesh.background log.decompose1 log.decompose2 log.probe log.reconstructPar log.reconstructParMesh log.residuals.png log.simpleFoam log.snappy log.snappy_layers log.surfaceFeatureExtract postProcessing processor0 processor1 processor2 processor3 system ``` ### tool: bash `cd /work/20260811-011037-e0c1/case` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case\npython3 - <<'EOF'\nimport pyvista as pv\npv.OFF_SCREEN=True\nreader = pv.OpenFOAMReader(\"case.foam\")\nprint(list(reader.time_values))\nreader.set_active_time_value(reader.time_values[-1])\nreader.cell_to_point_creation=False\nblock = reader.read()\nprint(block.keys())\nbm = block[\"boundary\"]\nprint(bm.keys())\nhull = bm[\"hull\"]\nareas = hull.compute_cell_sizes(length=False, area=True, volume=False).cell_data[\"Area\"]\nprint(\"hull patch area (simulated, y>0 half):\", areas.sum())\nEOF" } ``` **output** ``` exit_code: 0 [0.0, 1500.0] ['internalMesh', 'boundary'] ['inlet', 'outlet', 'ySymmetry', 'yFar', 'zSymmetry', 'zFar', 'hull'] hull patch area (simulated, y>0 half): 0.6602525312050673 ``` ### tool: bash `python3 - <<'EOF'` exit 0 **input** ``` { "cmd": "python3 - <<'EOF'\nimport math\nU = 1.36\nL = 3.0\nnu = 1.19e-6\nrho = 998.0\nS_full = 1.3391049260528305 # wetted surface, both sides, from STL geometry (excludes waterplane cap)\n\nFx_visc_half = 2.010459 # N, viscous (frictional) force on the y>0 half-model hull patch\nRf = 2*Fx_visc_half # full-ship frictional resistance, N\n\nRe = U*L/nu\nCf_ittc = 0.075/(math.log10(Re)-2)**2\n\nq = 0.5*rho*U**2*S_full\nCf_cfd = Rf/q\n\nprint(f\"Re = {Re:.4e}\")\nprint(f\"ITTC-57 Cf = {Cf_ittc:.6e}\")\nprint(f\"dynamic pressure * S = {q:.4f} N\")\nprint(f\"Rf (full ship, both sides) = {Rf:.4f} N\")\nprint(f\"Cf (CFD, frictional/viscous only) = {Cf_cfd:.6e}\")\nprint(f\"ratio CFD/ITTC = {Cf_cfd/Cf_ittc:.4f}\")\n\n# Also total resistance incl. pressure (form) component in this double-body run,\n# which has no wave resistance since no free surface, so \"pressure\" here is\n# pure... ``` **output** ``` exit_code: 0 Re = 3.4286e+06 ITTC-57 Cf = 3.646574e-03 dynamic pressure * S = 1235.9274 N Rf (full ship, both sides) = 4.0209 N Cf (CFD, frictional/viscous only) = 3.253361e-03 ratio CFD/ITTC = 0.8922 Rt (double-body total incl. viscous pressure/form) = 4.7118 N Ct (double-body, viscous+form only, no waves) = 3.812349e-03 form factor-ish Ct/Cf = 1.1718 ``` ### tool: bash `cd /work/20260811-011037-e0c1` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1\npython3 - <<'EOF'\nimport pyvista as pv\nimport numpy as np\npv.OFF_SCREEN=True\n\nreader = pv.OpenFOAMReader(\"case/case.foam\")\nreader.set_active_time_value(1500.0)\nreader.cell_to_point_creation = True\nblock = reader.read()\nmesh = block[\"internalMesh\"]\n\ncut = mesh.slice(normal=(0,0,1), origin=(0,0,-0.09))\ndata = cut.point_data[\"U\"]\ncut[\"Umag\"] = np.linalg.norm(data, axis=1)\n\np = pv.Plotter(off_screen=True, window_size=(1300,700))\np.add_mesh(cut, scalars=\"Umag\", cmap=\"viridis\", show_edges=False)\np.add_scalar_bar(title=\"|U| (m/s)\", n_labels=5)\np.view_xy()\np.enable_parallel_projection()\np.reset_camera(bounds=(-3,7,0,3.0,-1,1))\np.add_text(\"velocity magnitude, z=-0.09 (mid-draft) slice, double-body (no free surface)\", font_size=10)\np.screenshot(\"renders/U_wake_z.png\")\np.close()\nprint(\"done\")\nEOF" } ``` **output** ``` exit_code: 0 ``` ### tool: read_file `/work/20260811-011037-e0c1/renders/U_wake_z.png` **input** ``` { "path": "/work/20260811-011037-e0c1/renders/U_wake_z.png" } ``` **output** ``` [image/png, 22146 bytes] /work/20260811-011037-e0c1/renders/U_wake_z.png — 1300x700 image/png, 22144 bytes ``` ### tool: bash `cd /work/20260811-011037-e0c1` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1\npython3 - <<'EOF'\nimport pyvista as pv\nimport numpy as np\npv.OFF_SCREEN=True\n\nreader = pv.OpenFOAMReader(\"case/case.foam\")\nreader.set_active_time_value(1500.0)\nreader.cell_to_point_creation = True\nblock = reader.read()\nbnd = block[\"boundary\"]\nhull = bnd[\"hull\"]\n\nrho = 998.0\nU = 1.36\nq = 0.5*rho*U**2\np = np.asarray(hull.point_data[\"p\"]) # kinematic pressure p/rho [m2/s2]\ncp = (p*rho) / q # p/rho * rho / q = p_dyn... actually p field is p/rho already\nhull[\"Cp\"] = cp\n\npl = pv.Plotter(off_screen=True, window_size=(1300,900))\npl.add_mesh(hull, scalars=\"Cp\", cmap=\"coolwarm\", show_edges=False)\npl.add_scalar_bar(title=\"Cp = p/(0.5 rho U^2)\", n_labels=5)\npl.view_vector((-1,-1,0.6), viewup=(0,0,1))\npl.enable_parallel_projection()\npl.add_text(\"pressure coefficient on wetted hull (double-body, no free surface)\",... ``` **output** ``` exit_code: 0 done -0.055852495 0.75502276 ``` ### tool: read_file `/work/20260811-011037-e0c1/renders/Cp_hull.png` **input** ``` { "path": "/work/20260811-011037-e0c1/renders/Cp_hull.png" } ``` **output** ``` [image/png, 47889 bytes] /work/20260811-011037-e0c1/renders/Cp_hull.png — 1300x900 image/png, 47887 bytes ``` ### tool: bash `cd /work/20260811-011037-e0c1` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1\npython3 - <<'EOF'\nimport matplotlib\nmatplotlib.use(\"Agg\")\nimport matplotlib.pyplot as plt\nimport numpy as np\n\nCf_cfd = 3.253361e-03\nCf_ittc = 3.646574e-03\nCt_cfd = 3.812349e-03 # double-body total (friction + viscous pressure/form), still no wave resistance\n\nfig, axes = plt.subplots(1, 2, figsize=(11,5))\n\nax = axes[0]\nlabels = [\"ITTC-57\\ncorrelation line\", \"CFD\\nfrictional Cf\\n(double-body)\", \"CFD total Ct\\n(friction+form,\\nno waves)\"]\nvals = [Cf_ittc, Cf_cfd, Ct_cfd]\ncolors = [\"tab:gray\", \"tab:blue\", \"tab:orange\"]\nbars = ax.bar(labels, vals, color=colors)\nfor b,v in zip(bars, vals):\n ax.text(b.get_x()+b.get_width()/2, v+0.00005, f\"{v*1e3:.3f}e-3\", ha=\"center\", fontsize=9)\nax.set_ylabel(r\"Coefficient $C = R/(0.5\\rho U^2 S)$\")\nax.set_title(f\"Wigley hull, Fr=0.25, Re={3.4286e6:.2e}\\n(no free sur... ``` **output** ``` exit_code: 0 saved ``` ### tool: read_file `/work/20260811-011037-e0c1/renders/Cf_ITTC_comparison.png` **input** ``` { "path": "/work/20260811-011037-e0c1/renders/Cf_ITTC_comparison.png" } ``` **output** ``` [image/png, 90354 bytes] /work/20260811-011037-e0c1/renders/Cf_ITTC_comparison.png — 1650x750 image/png, 138923 bytes, sent at 1024px ``` ### agent Good headline figure. Let's check the residual convergence plot too, and clean up disk. ### tool: read_file `/work/20260811-011037-e0c1/case/log.residuals.png` **input** ``` { "path": "/work/20260811-011037-e0c1/case/log.residuals.png" } ``` **output** ``` [image/png, 122688 bytes] /work/20260811-011037-e0c1/case/log.residuals.png — 1080x600 image/png, 122686 bytes ``` ### tool: bash `cd /work/20260811-011037-e0c1/case` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case\nmv log.residuals.png ../renders/residuals.png\ndu -sh /work/20260811-011037-e0c1\nls postProcessing/hullForces/0/ 2>/dev/null; find postProcessing -maxdepth 3" } ``` **output** ``` exit_code: 0 37M /work/20260811-011037-e0c1 force.dat moment.dat postProcessing postProcessing/hullForces postProcessing/hullForces/0 postProcessing/hullForces/0/force.dat postProcessing/hullForces/0/moment.dat postProcessing/yPlus postProcessing/yPlus/0 postProcessing/yPlus/0/yPlus.dat ``` ### agent Excellent convergence — all residuals below 2×10⁻⁵ and flat, forces stable to the last iterations. Let's verify the force history plateaued and check the yPlus data over the run. ### tool: bash `cd /work/20260811-011037-e0c1/case` exit 0 **input** ``` { "cmd": "cd /work/20260811-011037-e0c1/case\ntail -5 postProcessing/hullForces/0/force.dat\necho ---\ntail -5 postProcessing/yPlus/0/yPlus.dat\necho ---\nawk 'NR>1{print $1}' postProcessing/hullForces/0/force.dat | tail -1" } ``` **output** ``` exit_code: 0 1460 2.3558598e+00 1.3635057e+01 -1.0366243e+01 3.4543215e-01 1.3594321e+01 -1.0345389e+01 2.0104277e+00 4.0735946e-02 -2.0854051e-02 1470 2.3558731e+00 1.3635031e+01 -1.0366218e+01 3.4543573e-01 1.3594296e+01 -1.0345362e+01 2.0104374e+00 4.0735618e-02 -2.0855626e-02 1480 2.3559303e+00 1.3635050e+01 -1.0366238e+01 3.4543555e-01 1.3594317e+01 -1.0345379e+01 2.0104947e+00 4.0733874e-02 -2.0858790e-02 1490 2.3559222e+00 1.3635014e+01 -1.0366256e+01 3.4542553e-01 1.3594282e+01 -1.0345396e+01 2.0104967e+00 4.0731861e-02 -2.0860188e-02 1500 2.3558927e+00 1.3635074e+01 -1.0366263e+01 3.4543412e-01 1.3594342e+01 -1.0345406e+01 2.0104585e+00 4.0732006e-02 -2.0857541e-02 --- 500 hull 3.2856926e+01 2.2352147e+02 8.3725632e+01 750 hull 3.2861917e+01 2.2352207e+02 8.3725299e+01 1000 hull 3.2857396e+01 2.2352185e+02 8.3725648e+01 1250 hull 3.2857778e+01 2.2352199e+02 8.3726207e+01 1500 hull 3.2860408e+01 2.2352145e+02 8.3725531e+01 --- 1500 ``` ### agent Force is flat to 4 significant figures over the last hundreds of iterations, and y+ (min/max/avg) is stable too. This is a solidly converged steady solve. Let's finalize the run and produce a short written summary, then clean up excess disk if needed. ### tool: bash `du -sh /work/20260811-011037-e0c1/case/processor* 2>/dev/null` exit 0 **input** ``` { "cmd": "du -sh /work/20260811-011037-e0c1/case/processor* 2>/dev/null\ndu -sh /work/20260811-011037-e0c1/*" } ``` **output** ``` exit_code: 0 5.4M /work/20260811-011037-e0c1/case/processor0 5.3M /work/20260811-011037-e0c1/case/processor1 5.2M /work/20260811-011037-e0c1/case/processor2 5.3M /work/20260811-011037-e0c1/case/processor3 36M /work/20260811-011037-e0c1/case 2.0K /work/20260811-011037-e0c1/render_hull_mesh.py 1009K /work/20260811-011037-e0c1/renders 43K /work/20260811-011037-e0c1/renders_geom ``` ### agent Small footprint, nothing to clean. Let me write a summary note in the workspace for the record. ### tool: write_file `/work/20260811-011037-e0c1/SUMMARY.md` **input** ``` { "path": "/work/20260811-011037-e0c1/SUMMARY.md", "content": "# Wigley hull — double-body viscous quick look\n\n## What was run\n- Geometry: `/work/geometry/wigley_hull_L3m.stl` — a closed solid (0 open edges, 1\n body) representing the **submerged hull, both sides** (y: ±0.15 m), capped flat\n at the waterline (z=0). Confirmed by inspection of `renders_geom/geometry.png`\n and by splitting the STL by face normal/location: the z=0 \"lid\" is 0.600 m² of\n the 1.939 m² total STL area; the real wetted skin is 1.339 m².\n- Domain: a **quarter domain** exploiting two symmetries — `ySymmetry` at y=0\n (the ship's own port/starboard symmetry) and `zSymmetry` at z=0 (the\n double-body trick: mirroring the submerged hull about the calm waterline\n instead of solving a free surface). Box: x ∈ [-4.5, 10.5] m (1.5L upstream,\n 3L downstream), y ∈ [0, 4.5] m, z ∈ [-4.5, 0] m (1.5L to th... ``` **output** ``` wrote 6239 bytes to /work/20260811-011037-e0c1/SUMMARY.md ``` ### tool: fetch `paths=['/work/20260811-011037-e0c1/renders/Cf_ITTC_comparison.png', '/work/202...` **input** ``` { "paths": [ "/work/20260811-011037-e0c1/renders/Cf_ITTC_comparison.png", "/work/20260811-011037-e0c1/renders/mesh_z_hull_closeup.png", "/work/20260811-011037-e0c1/renders/mesh_y_hull_closeup.png", "/work/20260811-011037-e0c1/renders/residuals.png", "/work/20260811-011037-e0c1/renders/U_wake_z.png", "/work/20260811-011037-e0c1/renders/Cp_hull.png", "/work/20260811-011037-e0c1/renders_geom/geometry.png", "/work/20260811-011037-e0c1/SUMMARY.md" ] } ``` **output** ``` copied 8 file(s) to the user's machine: C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260811-011037-e0c1\files\20260811-011037-e0c1\renders\Cf_ITTC_comparison.png C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260811-011037-e0c1\files\20260811-011037-e0c1\renders\mesh_z_hull_closeup.png C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260811-011037-e0c1\files\20260811-011037-e0c1\renders\mesh_y_hull_closeup.png C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260811-011037-e0c1\files\20260811-011037-e0c1\renders\residuals.png C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260811-011037-e0c1\files\20260811-011037-e0c1\renders\U_wake_z.png C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260811-011037-e0c1\files\20260811-011037-e0c1\renders\Cp_hull.png C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260811-011037-e0c1\files\20260811-011037-e0c1\renders_geom\geometry.png C:\Users\reach\Documents\Reynoldsv2\qa-runs\studies\20260811-011037-e0c1\files\20260811-011037-e0c1\SUMMARY.md ``` ### agent ## Summary **What I did:** built a quarter-domain double-body model of the Wigley hull (symmetry at the ship's own centreplane *and* at the calm waterline, so no free surface is solved), meshed it coarsely with `snappyHexMesh` (54k cells), checked the geometry and mesh by eye and with `checkMesh` before running anything, then ran one steady `simpleFoam`/`kOmegaSST` solve at U=1.36 m/s (Fr=0.25, Re=3.43e6) on 4 cores. It converged cleanly (residuals flat below 2e-5, forces flat to 4 sig figs) in under 3 minutes. **What I looked at first:** - Geometry render confirmed the STL is a closed solid = the submerged hull, full beam, capped flat at the waterline — not a half-beam shell as the wording suggested. I split off that cap (0.60 m² of 1.94 m² total) to get the true wetted skin area (1.339 m², both sides) for the coefficient. - Mesh close-ups show sane surface refinement and 4 boundary layers reaching ~92% of target thickness on the hull; `checkMesh` passed except for 12 skew faces out of 170k (negligible). Fit for a quick look. **Headline numbers:** - Re_L = 3.43×10⁶, Fr_L = 0.25 - **CFD frictional Cf = 3.253×10⁻³** - **ITTC-57 line at this Re: Cf = 3.647×10⁻³** → CFD is ~11% below the correlation - CFD double-body total (friction + viscous pressure/form, still zero wave drag): Ct = 3.812×10⁻³ → apparent form factor ≈ 1.17 (plausible for this hull) Figure: `renders/Cf_ITTC_comparison.png`. Supporting renders and full writeup with caveats are in `SUMMARY.md`, mirrored to your machine along with all the images. **What this is not:** a free-surface run — no wave resistance, no trim/sinkage. At Fr=0.25 the Wigley hull is known to sit near a resistance hump where wave drag is a large share of the total, so this Ct is *not* comparable to published total-resistance numbers for this hull, only to the viscous/form part of a resistance decomposition. **What a fuller study would cost**, roughly, if you want it: 1. Grid-convergence family (3 more meshes, Richardson extrapolation) — an afternoon of mostly-unattended compute. 2. y+ sensitivity / resolved sublayer check — modest addition on top of (1). 3. Free surface (VOF, transient, trim/sinkage) — the real ask if you want "the" resistance number; hours to about a day of solver time, more meshing care for wave resolution. 4. A Froude sweep to trace the hump/hollow curve — roughly N× the cost of (3). I haven't started any of that — no refinement ladder, no transient run — pending your steer on which of those is worth the spend. ## 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.