embedded3 S2-7b: the curved-wall instrument (tests/embedded3_wall_position_curved.rs: Taylor–Couette between embedded cylinders, rigid-rotation linear mode, outer-driven mode; walls' effective radii, pressure error by cell class against the exact p(r), wall-flux and ghost diagnostics); the sphere operator probe's sub-bands and force units; two host prototypes, default off, device refuses them: RTX_E3_WALL_EXCHANGE=axisfoot (the axis exchange takes the wall velocity at the axis foot — the S2-7 default read the solid face's own value, exact only for a uniform wall velocity: rigid rotation A 1.012 → 1.003) and RTX_E3_CONV_SIDES=exact (convective mass fluxes from the sides' own apertures; moves nothing)

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

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

@@ -221,6 +221,8 @@ impl Mask {
             wall_exchange_axis: false,
             cv_sides_exact: false,
             wall_order2_centroid: false,
+            wall_exchange_foot: false,
+            conv_sides_exact: false,
             grad_weights: None,
             diffusion_centroid: false,
             face_shifts: None,
@@ -435,6 +437,29 @@ impl Mask {
     /// crosses a side (the in-plane momentum residual on oblique walls).
     /// `None` at a domain side (the default stays).
     fn exact_cv_sides(&self, cut: &CutGeometry, c: usize, p: [i64; 3]) -> Option<[[f64; 2]; 3]> {
+        let parts = self.exact_cv_side_parts(cut, c, p)?;
+        let mut ap = [[1.0; 2]; 3];
+        for d in 0..3 {
+            for side in 0..2 {
+                ap[d][side] = if d == c {
+                    parts[d][side].0
+                } else {
+                    0.5 * (parts[d][side].0 + parts[d][side].1)
+                };
+            }
+        }
+        Some(ap)
+    }
+
+    /// The parts of [`Self::exact_cv_sides`]: across `c`, the (far half of
+    /// `cell_minus`'s face, near half of `cell_plus`'s face) apertures per
+    /// side; along `c`, the centre plane's aperture (twice).
+    pub(super) fn exact_cv_side_parts(
+        &self,
+        cut: &CutGeometry,
+        c: usize,
+        p: [i64; 3],
+    ) -> Option<[[(f64, f64); 2]; 3]> {
         let lat = self.lattice();
         let g = self.grid;
         let mut pm = p;
@@ -456,7 +481,7 @@ impl Mask {
                 corner(cell, o)
             }
         };
-        let mut ap = [[1.0; 2]; 3];
+        let mut ap = [[(1.0, 1.0); 2]; 3];
         for d in 0..3 {
             if d == c {
                 // The two cells' centre planes across `c`: corners at the
@@ -469,7 +494,8 @@ impl Mask {
                         o[d2] = o2;
                         value(*cell, o, true)
                     };
-                    ap[d][side] = super::cut::quad_fraction(mid(0, 0), mid(1, 0), mid(0, 1), mid(1, 1));
+                    let a = super::cut::quad_fraction(mid(0, 0), mid(1, 0), mid(0, 1), mid(1, 1));
+                    ap[d][side] = (a, a);
                 }
             } else {
                 let e = 3 - c - d;
@@ -496,7 +522,7 @@ impl Mask {
                             super::cut::quad_fraction(at(0, 0), at(1, 0), at(0, 1), at(1, 1))
                         }
                     };
-                    ap[d][side] = 0.5 * (half(cells[0], true) + half(cells[1], false));
+                    ap[d][side] = (half(cells[0], true), half(cells[1], false));
                 }
             }
         }