Dangling

1 files changed, 56 insertions, 0 deletions

diff --git a/csv_test.py b/csv_test.py
new file mode 100755
index 0000000..e6077fd
--- /dev/null
+++ b/csv_test.py
@@ -0,0 +1,56 @@
+#!/usr/bin/env python3
+
+import argparse
+import numpy as np
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        description="Calculate drag coefficient from LBM CSV data."
+    )
+
+    parser.add_argument("force_csv")
+    parser.add_argument("momentum_csv")
+    parser.add_argument("density_csv")
+
+    parser.add_argument("--U", type=float, default=0.003)
+    parser.add_argument("--D", type=float, default=10.0)
+    parser.add_argument("--rho", type=float, default=1.0)
+
+    args = parser.parse_args()
+
+    # Load CSVs
+    force = np.loadtxt(args.force_csv, delimiter=",")
+    momentum = np.loadtxt(args.momentum_csv, delimiter=",")
+    density = np.loadtxt(args.density_csv, delimiter=",")
+
+    # If each file is just a scalar field:
+    Fx = force
+    px = momentum
+    rho = density
+
+    # Total force
+    F_drag = abs(np.sum(Fx))
+
+    # 2D cylinder, unit depth
+    A_ref = args.D
+
+    # Dynamic pressure
+    q = 0.5 * args.rho * args.U**2
+
+    # Drag coefficient
+    Cd = F_drag / (q * A_ref)
+
+    print(f"Total Fx       = {np.sum(Fx):.8e}")
+    print(f"Drag force     = {F_drag:.8e}")
+    print(f"Reference area = {A_ref:.8e}")
+    print(f"Cd             = {Cd:.8f}")
+
+    print("\nDiagnostics:")
+    print(f"rho: min={rho.min():.6e}, max={rho.max():.6e}, mean={rho.mean():.6e}")
+    print(f"px:  min={px.min():.6e}, max={px.max():.6e}, mean={px.mean():.6e}")
+    print(f"Fx:  min={Fx.min():.6e}, max={Fx.max():.6e}, mean={Fx.mean():.6e}")
+
+
+if __name__ == "__main__":
+    main()