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CelerisLab/tests/validation/run_dfg_re20.py
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ClaudeandClaude Opus 5.5 9b8ff90609 test: add DFG 2D-1 Re20 runner against official reference intervals
Reuses the pinned Re100 runner and helpers unchanged; sets only the
lattice viscosity for Re 20. Reports Cd, Cl and p_diff (dp * 0.04 for
U = 0.2 m/s), a steady rule frozen before any run (window ranges at most
a tenth of each official interval width) and no interval verdict when
not steady. Declares the pressure-NEQ outlet and Zou-He inlet deviations.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-20 13:37:19 +00:00

207 lines
10 KiB
Python

"""Steady DFG 2D-1 (Re 20): refined and uniform runs against the official reference intervals.
Not a full benchmark certification. Declared deviations from the official setup:
pressure-NEQ outlet (``neq_extrap``) instead of do-nothing, local Zou-He inlet.
Geometry, inflow profile, initial state, refined layout and observation reuse the
pinned Re100 runner (``run_refined_dfg``) and ``re100_helpers`` unchanged; only the
lattice viscosity is set for Re 20 (nu = U_lattice * D / 20 at the root level).
Units. The helpers use scaled DFG units with mean inflow speed 1, so
Cd = 2 Fx / (rho U^2 D) and Cl = 2 Fy / (rho U^2 D) are scale-free, and
``pressure_probes`` returns dp / (rho U^2). The official p_diff = p(0.15, 0.2) -
p(0.25, 0.2) uses U = 0.2 m/s, rho = 1, so p_diff = dp * 0.04. Both are reported;
only p_diff is compared with the official interval. Forces use the existing sign
convention (positive Cd along the inflow, positive Cl towards +y).
Sampling. One sample every SAMPLE_TSTAR (t* = U t / D): Cd and Cl are the mean
over that interval (window exchange ledger refined, per-batch forces uniform);
p_diff is the end-of-interval value at the exact surface points.
Steady rule (frozen before any run). Over the trailing WINDOW_TSTAR, the range
(max - min) of each of Cd, Cl and p_diff must not exceed one tenth of the width of
its official interval. Absolute ranges avoid dividing by the small Cl. If the rule
fails at TSTAR_MAX the run reports "not steady" and gives no interval verdict.
"""
import argparse
import json
import math
import os
from pathlib import Path
import sys
import time
from tempfile import TemporaryDirectory
import numpy as np
HERE = Path(__file__).resolve().parent
sys.path.insert(0, str(HERE))
import run_refined_dfg as rr # noqa: E402
RE = 20.0
U_PHYS = 0.2 # m/s mean inflow; rho = 1
TSTAR_MAX = 60.0 # 30 s physical
SAMPLE_TSTAR = 0.5
WINDOW_TSTAR = 10.0 # trailing 5 s
# Schaefer & Turek (1996), 2D-1 lower/upper bounds.
BANDS = dict(cd=(5.57, 5.59), cl=(0.0104, 0.0110), p_diff=(0.1172, 0.1176))
STEADY_RANGE = {k: (hi - lo) / 10 for k, (lo, hi) in BANDS.items()}
DEVIATIONS = ("pressure-NEQ outlet (neq_extrap), not do-nothing", "local Zou-He inlet")
_re100_config = rr.config
def config(h, diameter, collision="SRT", jet_scenario="none"):
"""The pinned Re100 configuration with the lattice viscosity set for Re 20."""
if jet_scenario != "none":
raise ValueError("DFG 2D-1 runs have no Jets")
cfg, body, p = _re100_config(h, diameter, collision, jet_scenario)
nu = p["mean_speed"] * p["diameter"] / RE
cfg["physics"]["viscosity"] = nu
return cfg, body, dict(p, viscosity=nu, re=RE)
def lattice_parameters(diameter, speed=rr.SPEED):
nu = speed * diameter / RE
return dict(viscosity=nu, tau=0.5 + 3 * nu, steps=math.ceil(TSTAR_MAX * diameter / speed),
interval=round(SAMPLE_TSTAR * diameter / speed))
def sample(impulse, n, diameter, dp):
den = rr.SPEED**2 * diameter / 2
return dict(cd=float(impulse[0] / n / den), cl=float(impulse[1] / n / den),
dp_scaled=float(dp), p_diff=float(dp) * U_PHYS**2)
def summarize(rows):
"""Steady rule over the trailing window, then the interval verdict (or none)."""
if not rows or rows[-1]["tstar"] < TSTAR_MAX - 1e-9:
return dict(status="INCOMPLETE", steady=False, verdict=None)
window = [r for r in rows if r["tstar"] >= TSTAR_MAX - WINDOW_TSTAR - 1e-9]
ranges = {k: max(r[k] for r in window) - min(r[k] for r in window) for k in BANDS}
steady = all(ranges[k] <= STEADY_RANGE[k] for k in BANDS)
final = {k: rows[-1][k] for k in BANDS}
result = dict(window_samples=len(window), ranges=ranges, steady_limits=STEADY_RANGE,
steady=steady, final=final, bands=BANDS, deviations=DEVIATIONS)
if not steady:
return dict(result, status="NOT_STEADY", verdict=None)
inside = {k: BANDS[k][0] <= final[k] <= BANDS[k][1] for k in BANDS}
return dict(result, status="WITHIN_INTERVALS" if all(inside.values()) else "OUTSIDE_INTERVALS",
verdict=inside)
def healthy(row):
return row["max_mach"] <= 0.2 and row["rho_min"] >= 0.5 and row["rho_max"] <= 1.5
def run_case(a, h, case):
from contextlib import ExitStack
from CelerisLab.cuda.context import CudaContext
from CelerisLab.lbm.descriptors import FLUID
from CelerisLab.lbm.refinement_stepper import FixedPatchStepper
from CelerisLab.simulation import Simulation
refined = case == "refined"
cfgdict, bodydict, p = config(h, 40 if refined else 80, a.collision)
lp = lattice_parameters(p["diameter"])
rows = []
with ExitStack() as stack:
if refined:
cfg, pair, body, host = rr.host_geometry(a.source, h, a.collision)
context = stack.enter_context(CudaContext(0))
backend = stack.enter_context(FixedPatchStepper(
cfg, rr.PLACEMENTS["wide"], context=context, coarse_boundary="channel",
base_block=rr.BASE_BLOCK, fine_block=rr.FINE_BLOCK, fine_objects=(body,),
observe_raw_exchange=True, observe_window_exchange=True))
from CelerisLab.lbm.channel import channel_masks
from CelerisLab.lbm.refinement import ACTIVE
from CelerisLab.lbm.descriptors import SOLID
masks = [channel_masks(pair.coarse_shape)[0] & ~pair.covered,
(pair.fine_kind == ACTIVE)
& ((host.flags.reshape(pair.fine_shape) & SOLID) == 0)]
backend.initialize(rr.initial_state(pair.coarse_shape, (0.0, 0.0), 1.0, root=True),
rr.initial_state(pair.fine_shape, pair.fine_origin, 0.5))
probe_p = dict(p, center=[(80.5 - pair.fine_origin[0]) / 0.5 - 0.5,
(81.0 - pair.fine_origin[1]) / 0.5 - 0.5], radius=40.0)
else:
tmp = Path(stack.enter_context(TemporaryDirectory()))
(tmp / "lbm.json").write_text(json.dumps(cfgdict))
(tmp / "body.json").write_text(json.dumps(bodydict))
sim = stack.enter_context(Simulation(str(tmp / "lbm.json"), str(tmp / "body.json"),
device_id=0))
sim.initialize()
probe_p = p
fluid = (sim.field.flag.reshape(p["ny"], p["nx"]) & FLUID) != 0
begin = 0
while begin < lp["steps"]:
rr.check_deadline(a.deadline)
n = min(lp["interval"], lp["steps"] - begin)
if refined:
impulse = rr.advance_refined_interval(backend, n, a.deadline, "window")
fields = [rr.macros(g) for g in backend.download()]
rho, ux, uy = fields[1]
fluid = masks[1]
vals = [tuple(v[m] for v in f) for m, f in zip(masks, fields)]
else:
impulse, done = np.zeros(2), 0
while done < n:
batch = min(100, n - done)
sim.run(batch)
impulse += sim.read_force(0).astype(np.float64) * batch
done += batch
m = sim.get_macroscopic()
rho, ux, uy = [np.asarray(m[k], np.float64).reshape(p["ny"], p["nx"])
for k in ("rho", "ux", "uy")]
vals = [(rho[fluid], ux[fluid], uy[fluid])]
begin += n
row = dict(step=begin, tstar=begin * rr.SPEED / p["diameter"],
**sample(impulse, n, p["diameter"],
h.pressure_probes(rho, fluid, probe_p)["dp"]),
rho_min=float(min(v[0].min() for v in vals)),
rho_max=float(max(v[0].max() for v in vals)),
max_mach=float(max(np.sqrt(3 * (v[1]**2 + v[2]**2)).max() for v in vals)))
rr.ensure_finite(row)
rows.append(row)
if not healthy(row):
break
summary = summarize(rows) if healthy(rows[-1]) else dict(status="UNHEALTHY", steady=False,
verdict=None)
return dict(case=case, collision=a.collision, lattice=lp, rows=rows, **summary)
def plan(collision="SRT"):
return dict(re=RE, collision=collision, tstar_max=TSTAR_MAX, sample_tstar=SAMPLE_TSTAR,
window_tstar=WINDOW_TSTAR, bands=BANDS, steady_limits=STEADY_RANGE,
deviations=DEVIATIONS, pressure_scale=U_PHYS**2,
refined_root=lattice_parameters(40), refined_fine_tau=0.5 + 3 * 2 * rr.SPEED * 40 / RE,
uniform=lattice_parameters(80),
label="compared with official reference intervals; not a full benchmark certification")
def main():
parser = argparse.ArgumentParser(description=__doc__.splitlines()[0])
parser.add_argument("--case", choices=["both", "refined", "uniform"], default="both")
parser.add_argument("--collision", choices=["SRT", "MRT"], default="SRT")
parser.add_argument("--source", type=Path, default=rr.DEFAULT_SOURCE)
parser.add_argument("--output", type=Path, required=True)
parser.add_argument("--plan", action="store_true", help="Write the frozen plan; no CUDA")
parser.add_argument("--max-wall-seconds", type=float)
a = parser.parse_args()
a.source = a.source.resolve()
a.output.mkdir(parents=True, exist_ok=False)
(a.output / "plan.json").write_text(json.dumps(plan(a.collision), indent=2, allow_nan=False))
if a.plan:
return
if not a.max_wall_seconds or a.max_wall_seconds <= 0 or not os.environ.get("CUDA_VISIBLE_DEVICES"):
raise SystemExit("GPU run needs --max-wall-seconds > 0 and explicit CUDA_VISIBLE_DEVICES")
h, _ = rr.helpers(a.source)
rr.config = config # host_geometry builds its root configuration through this name
a.deadline = time.monotonic() + a.max_wall_seconds
cases = ["refined", "uniform"] if a.case == "both" else [a.case]
results = [run_case(a, h, case) for case in cases]
(a.output / "result.json").write_text(json.dumps(results, indent=2, allow_nan=False))
if __name__ == "__main__":
main()