Add jet, surface and fixed-patch tests and runnable examples

tests/integration/_cases.py

@@ -0,0 +1,24 @@
+"""Explicit, isolated low-Mach GPU test configuration."""
+import json
+from pathlib import Path
+from tempfile import TemporaryDirectory
+
+from CelerisLab.simulation import Simulation
+
+
+def make_sim(nx=128, ny=64, *, streaming="double_buffer", precision="FP32",
+             shifted=False, collision="SRT", y_wall="bounce_back", **physics):
+    config_path = Path(__file__).resolve().parents[2] / "src/CelerisLab/configs/config_lbm.json"
+    cfg = json.loads(config_path.read_text())
+    cfg["grid"].update(nx=nx, ny=ny, nz=1, lattice_model="D2Q9")
+    cfg["physics"].update(viscosity=0.05, velocity=0.02, rho=1.0)
+    cfg["physics"].update(physics)
+    cfg["method"].update(collision=collision, streaming=streaming,
+                          store_precision=precision, ddf_shifting=shifted, y_wall_bc=y_wall)
+    cfg["method"]["les"]["enabled"] = False
+    with TemporaryDirectory(prefix="celeris-test-config-") as temp:
+        lbm = Path(temp) / "lbm.json"
+        bodies = Path(temp) / "bodies.json"
+        lbm.write_text(json.dumps(cfg))
+        bodies.write_text('{"objects": []}')
+        return Simulation(lbm_config_path=str(lbm), body_config_path=str(bodies))