embedded3: cut predictor convection carries ρ (host + e3_cut.cu; density-scaling pin); operator load route includes the wall exchange (exchange.rs); reconstructed_parts, probe aperture floor knob; dfg_split diagnostic test

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

crates/specialized/rtx-cfd/src/solvers/incompressible/embedded3/cutwall.rs

@@ -207,6 +207,8 @@ impl Mask {
             step_apertures: None,
             step_open: None,
             merge_master: Vec::new(),
+            scheme: crate::solvers::incompressible::ConvectionScheme::Upwind,
+            density: 1.0,
         };
         mask.compute_merging(None);
         Ok(mask)
@@ -564,7 +566,8 @@ impl Mask {
     /// without a cut geometry.
     pub fn cut_wall_force(&self, body: &Body, f: &Field, mu: f64, t: f64) -> Option<[f64; 3]> {
         let (p, s) = self.cut_wall_force_parts(body, f, mu, t)?;
-        Some([p[0] + s[0], p[1] + s[1], p[2] + s[2]])
+        let x = self.cut_wall_exchange_force(body, f, mu, self.density, t, None)?;
+        Some([p[0] + s[0] + x[0], p[1] + s[1] + x[1], p[2] + s[2] + x[2]])
     }
 
     /// The reconstructed wall route (S2-1 remedy): on every wall polygon
@@ -585,12 +588,26 @@ impl Mask {
         t: f64,
         planes: Option<(usize, usize)>,
     ) -> Option<[f64; 3]> {
+        let (p, s) = self.cut_wall_force_reconstructed_parts(body, f, mu, t, planes)?;
+        Some([p[0] + s[0], p[1] + s[1], p[2] + s[2]])
+    }
+
+    /// The reconstructed route split into its pressure and shear parts.
+    pub fn cut_wall_force_reconstructed_parts(
+        &self,
+        body: &Body,
+        f: &Field,
+        mu: f64,
+        t: f64,
+        planes: Option<(usize, usize)>,
+    ) -> Option<([f64; 3], [f64; 3])> {
         let cut = self.cut.as_ref()?;
         let g = self.grid;
         let (k0, k1) = planes.unwrap_or((0, g.nz));
         let h = g.dx.min(g.dy).min(g.dz);
         let (d1, d2) = (h, 2.0 * h);
         let mut force = [0.0; 3];
+        let mut shear = [0.0; 3];
         for (idx, w) in cut.wall.iter().enumerate() {
             let area = (w[0] * w[0] + w[1] * w[1] + w[2] * w[2]).sqrt();
             if area == 0.0 || !self.cell_fluid[idx] {
@@ -645,10 +662,10 @@ impl Mask {
                 let dn = wall_gradient(t1[c] - ts[c], t2[c] - ts[c]);
                 // Traction on the body = −(fluid stress on the fluid side):
                 // the shear the fluid exerts on the wall along +t.
-                force[c] += mu * dn * area;
+                shear[c] += mu * dn * area;
             }
         }
-        Some(force)
+        Some((force, shear))
     }
 
     /// The cut-cell load route restricted to the cells (and faces) of the
@@ -663,8 +680,13 @@ impl Mask {
         (k0, k1): (usize, usize),
     ) -> Option<[f64; 3]> {
         let (p, s) = self.cut_wall_force_parts_in(body, f, mu, t, Some((k0, k1)))?;
+        let x = self.cut_wall_exchange_force(body, f, mu, self.density, t, Some((k0, k1)))?;
         let lz = (k1 - k0) as f64 * self.grid.dz;
-        Some([(p[0] + s[0]) / lz, (p[1] + s[1]) / lz, (p[2] + s[2]) / lz])
+        Some([
+            (p[0] + s[0] + x[0]) / lz,
+            (p[1] + s[1] + x[1]) / lz,
+            (p[2] + s[2] + x[2]) / lz,
+        ])
     }
 
     /// The cut-cell load route split into its pressure and shear parts.