From 3eb40f98cedda91a7ea018ad2e18372b16105036 Mon Sep 17 00:00:00 2001
From: Omar Sobh <om.sobh@gmail.com>
Date: Thu, 17 Sep 2026 23:19:07 -0500
Subject: [PATCH] embedded3: the flag driver logs the reconstructed wall route
 per sample and in the final read

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
---
 .../rtx-cfd/tests/embedded3_flag_wake.rs      | 25 +++++++++++++++----
 1 file changed, 20 insertions(+), 5 deletions(-)

diff --git a/crates/specialized/rtx-cfd/tests/embedded3_flag_wake.rs b/crates/specialized/rtx-cfd/tests/embedded3_flag_wake.rs
index 2e6b43d..55740da 100644
--- a/crates/specialized/rtx-cfd/tests/embedded3_flag_wake.rs
+++ b/crates/specialized/rtx-cfd/tests/embedded3_flag_wake.rs
@@ -202,7 +202,7 @@ fn flag_wake_on_the_device() {
         let mut f = std::fs::File::create(p).expect("csv");
         writeln!(
             f,
-            "t,tip,drag_span,lift_span,drag_total,lift_total,residual,cg,fresh"
+            "t,tip,drag_span,lift_span,drag_total,lift_total,residual,cg,fresh,drag_rec,lift_rec"
         )
         .unwrap();
         f
@@ -214,6 +214,7 @@ fn flag_wake_on_the_device() {
     let mid = nz / 2;
     let slab = (mid - 2, mid + 2);
     let start = std::time::Instant::now();
+    let mut drag_rec_sum = 0.0;
     let (mut drag_sum, mut lift_min, mut lift_max, mut samples) =
         (0.0, f64::INFINITY, f64::NEG_INFINITY, 0usize);
     let mut worst_residual = 0.0_f64;
@@ -234,15 +235,25 @@ fn flag_wake_on_the_device() {
             let fs = mask
                 .cut_wall_force_per_span(body, &field, RHO * NU, t, slab)
                 .expect("wall");
+            // The reconstructed wall route on the same slab, per span.
+            let fr = mask
+                .cut_wall_force_reconstructed(body, &field, RHO * NU, t, Some(slab))
+                .map(|v| {
+                    let lz = (slab.1 - slab.0) as f64 * h;
+                    [v[0] / lz, v[1] / lz, v[2] / lz]
+                })
+                .expect("reconstructed");
             let ft = mask
                 .cut_wall_force(body, &field, RHO * NU, t)
                 .expect("wall");
             let tip = deflection(1.0, t).0;
             if sample {
                 println!(
-                    "  t {t:7.4} (tip {tip:+.4}): drag/span {:.1} lift/span {:+.1} N/m; total {:.3} {:+.3} N; residual {:.1e} CG {} fresh {}; [{:.0} s]",
+                    "  t {t:7.4} (tip {tip:+.4}): drag/span {:.1} lift/span {:+.1} N/m (reconstructed {:.1} {:+.1}); total {:.3} {:+.3} N; residual {:.1e} CG {} fresh {}; [{:.0} s]",
                     fs[0],
                     fs[1],
+                    fr[0],
+                    fr[1],
                     ft[0],
                     ft[1],
                     r.final_residual,
@@ -253,19 +264,22 @@ fn flag_wake_on_the_device() {
                 if let Some(f) = csv.as_mut() {
                     writeln!(
                         f,
-                        "{t:.5},{tip:.5},{:.4},{:.4},{:.5},{:.5},{:.3e},{},{}",
+                        "{t:.5},{tip:.5},{:.4},{:.4},{:.5},{:.5},{:.3e},{},{},{:.4},{:.4}",
                         fs[0],
                         fs[1],
                         ft[0],
                         ft[1],
                         r.final_residual,
                         r.poisson_iterations,
-                        r.fresh_cells
+                        r.fresh_cells,
+                        fr[0],
+                        fr[1]
                     )
                     .unwrap();
                 }
                 if t >= last_period_start {
                     drag_sum += fs[0];
+                    drag_rec_sum += fr[0];
                     lift_min = lift_min.min(fs[1]);
                     lift_max = lift_max.max(fs[1]);
                     samples += 1;
@@ -281,8 +295,9 @@ fn flag_wake_on_the_device() {
         }
     }
     let drag_mean = drag_sum / samples.max(1) as f64;
+    let drag_rec = drag_rec_sum / samples.max(1) as f64;
     println!(
-        "  FINAL ny {ny}: last period drag/span mean {drag_mean:.1} N/m (2D FSI2 224.6), lift/span {lift_min:+.1} … {lift_max:+.1} (2D ±215 flat tip, ±256 semicircle); worst residual {worst_residual:.1e}; {} phases written; {:.0} s",
+        "  FINAL ny {ny}: last period drag/span mean {drag_mean:.1} N/m (reconstructed {drag_rec:.1}; 2D FSI2 224.6, the 2D reference of this kinematics 208.3), lift/span {lift_min:+.1} … {lift_max:+.1} (2D ±215 flat tip, ±256 semicircle); worst residual {worst_residual:.1e}; {} phases written; {:.0} s",
         next_phase,
         start.elapsed().as_secs_f64()
     );