ClaudeandCodex
6a03f463bc
Samples every 0.5 s at synchronized root steps; trailing 5 s window (11
samples); range and |slope*window| each at most 1 % of the official band
width. States the fluid-on-cylinder force sign, reports cd_positive,
defaults to the refined case and uses the review's label.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
(cherry picked from commit 71221837f9)
2.4 KiB
DFG 2D-1 (Re 20) against the official reference intervals
tests/validation/run_dfg_re20.py runs the steady DFG 2D-1 case on the refined
channel root (D40 root, D80 wide fine patch) and on the uniform D80 grid. Geometry,
inflow, initial state, layout and observation are those of the pinned Re100 runner
(run_refined_dfg.py, re100_helpers.py, both unchanged); only the lattice
viscosity is set for Re 20 (root tau 0.56, fine 0.62, uniform 0.62, lattice speed 0.01).
Label: "compared against the official reference bands", not a full benchmark
certification: the outlet is pressure-NEQ (neq_extrap), not do-nothing, and the
inlet is local Zou-He.
Quantities
- Cd = 2 Fx / (rho U^2 D), Cl = 2 Fy / (rho U^2 D), interval means over each sample.
- p_diff = p(0.15, 0.2) - p(0.25, 0.2), linear extrapolation to the exact surface
points (
re100_helpers.pressure_probes). The helper returns dp / (rho U^2) in scaled units; p_diff = dp * 0.04 for U = 0.2 m/s, rho = 1. Both are reported. - Official intervals (Schaefer & Turek 1996): Cd [5.57, 5.59], Cl [0.0104, 0.0110], p_diff [0.1172, 0.1176].
Bounds and steady rule (frozen before any run)
- End time t* = 60 (30 s physical): 240,000 refined root steps, 480,000 uniform steps.
- One sample every t* = 1 (0.5 s) at the end of a synchronized root step; trailing window t* = 10 (last 5 s, 11 samples).
- Steady: in the window, both max - min and |least-squares slope x window| of each of Cd, Cl, p_diff are at most 1 % of its official interval width (2e-4, 6e-6, 4e-6). Absolute limits, so the small Cl is never a divisor. Never relaxed after a run.
- Force sign: fluid on cylinder, x along the inflow, y up from the bottom wall; Cd > 0
and the official Cl > 0 (
cd_positiveis reported). - Not steady at t* = 60: status
NOT_STEADY, no interval verdict. Health limits (Mach <= 0.2, rho in [0.5, 1.5]) stop the run withUNHEALTHY. - Steady:
WITHIN_INTERVALSorOUTSIDE_INTERVALS, with the per-quantity verdict.
Run
python tests/validation/run_dfg_re20.py --output <new-dir> --plan
CUDA_VISIBLE_DEVICES=<n> python tests/validation/run_dfg_re20.py --case refined \
--collision SRT --output <new-dir> --max-wall-seconds <cap>
Run --case uniform only if the refined result is outside a band. --plan writes plan.json only. A GPU run writes plan.json and result.json
(per case: lattice parameters, every sample, window ranges, status, verdict).
Host contract tests: tests/unit/test_dfg_re20.py.