embedded3 S2-1 remedy: the reconstructed wall route on the cut geometry's polygons (two probes along the interpolant normal) — sphere MMS 11.3/8.3 % (the best route); wired into the DFG and flag drivers

Co-Authored-By: Claude Fable 5.1 <[email protected]>

crates/specialized/rtx-cfd/tests/embedded3_dfg_2z.rs

@@ -141,7 +141,15 @@ fn dfg_3d_2z_on_the_device() {
             );
             let fcv =
                 mask.control_volume_force_with_walls(&field, dt, RHO, RHO * NU, None, bx, true);
-            let fs = mask.surface_force(body, &field, RHO * NU, t, 0.5 * h);
+            // The reconstructed wall route (two probes on the cut polygons).
+            let fr = mask
+                .cut_wall_force_reconstructed(body, &field, RHO * NU, t, None)
+                .expect("reconstructed");
+            let fs = rtx_cfd::solvers::incompressible::embedded3::SurfaceForce {
+                f: fr,
+                samples: 0,
+                skipped: 0,
+            };
             let (cd_s, cl_s) = (coef * fs.f[0], coef * fs.f[1]);
             let zc = 0.5 * H;
             let p_front = mask
@@ -153,7 +161,7 @@ fn dfg_3d_2z_on_the_device() {
             let dp = p_front - p_back;
             let (cd, cl, cd_cv, cl_cv) = (coef * fw[0], coef * fw[1], coef * fcv[0], coef * fcv[1]);
             println!(
-                "  t {t:8.4}: c_D {cd:.4} (CV {cd_cv:.4}, sampler {cd_s:.4} skipped {})  c_L {cl:.5} (CV {cl_cv:.5}, sampler {cl_s:.5})  Δp {dp:.4}  residual {:.1e} CG {}  [{:.0} s]",
+                "  t {t:8.4}: c_D {cd:.4} (CV {cd_cv:.4}, reconstructed {cd_s:.4} skipped {})  c_L {cl:.5} (CV {cl_cv:.5}, reconstructed {cl_s:.5})  Δp {dp:.4}  residual {:.1e} CG {}  [{:.0} s]",
                 fs.skipped,
                 r.final_residual,
                 r.poisson_iterations,
@@ -194,7 +202,7 @@ fn dfg_3d_2z_on_the_device() {
     }
     let (cd, cl, cd_cv, cl_cv, dp) = last.expect("samples");
     println!(
-        "  FINAL ny {ny}: c_D {cd:.4} (CV {cd_cv:.4}, routes {:.2e} apart; sampler {:.4}, {:.2e} from CV)  c_L {cl:.5} (CV {cl_cv:.5}, sampler {:.5})  Δp {dp:.4}  — reference c_D 6.05–6.25, c_L 0.008–0.010, Δp 0.165–0.175; {:.0} s",
+        "  FINAL ny {ny}: c_D {cd:.4} (CV {cd_cv:.4}, routes {:.2e} apart; reconstructed {:.4}, {:.2e} from CV)  c_L {cl:.5} (CV {cl_cv:.5}, reconstructed {:.5})  Δp {dp:.4}  — reference c_D 6.05–6.25, c_L 0.008–0.010, Δp 0.165–0.175; {:.0} s",
         ((cd - cd_cv) / cd).abs(),
         last_sampler.0,
         ((last_sampler.0 - cd_cv) / cd_cv).abs(),

crates/specialized/rtx-cfd/tests/embedded3_embedded_mms.rs

@@ -60,7 +60,7 @@ fn ladder(resolutions: &[usize], scheme: WallScheme) -> Ladder {
             mm.force_sampler[2] - fe[2],
         ]) / f_scale;
         println!(
-            "  n = {n:3}  L2 u {:.4e} (order {rate})  max div {:.2e}  ghost corr {:.2e}  F_surface {:.4?} rel {s:.3e} (skipped {})  F_cv {:.4?} rel {c:.3e}  F_sampler rel {a:.3e}",
+            "  n = {n:3}  L2 u {:.4e} (order {rate})  max div {:.2e}  ghost corr {:.2e}  F_surface {:.4?} rel {s:.3e} (skipped {})  F_cv {:.4?} rel {c:.3e}  F_reconstructed rel {a:.3e}",
             mm.l2_velocity,
             mm.max_div,
             mm.ghost_correction,

crates/specialized/rtx-cfd/tests/embedded3_sphere/mod.rs

@@ -258,7 +258,9 @@ pub fn measure(n: usize, scheme: WallScheme, c: (f64, f64, f64)) -> Measurement
     let force_cv = mask.control_volume_force(&f, dt, RHO, MU, Some(&src), (i0, i1, i0, i1, i0, i1));
     let force_sampler = match scheme {
         WallScheme::GhostBinary => surface.f,
-        WallScheme::CutCell => mask.surface_force(body, &f, MU, t, 0.5 * h).f,
+        WallScheme::CutCell => mask
+            .cut_wall_force_reconstructed(body, &f, MU, t, None)
+            .expect("reconstructed"),
     };
     Measurement {
         l2_velocity: (sq / vol).sqrt(),