P6-b design 2: the Robin wall on the patch's Inner side — RobinWall { alpha, datum } with the wall velocity u_s + (t_f − datum)/α (explicit, damped by the wall's own viscous gain μ/(α d)) and the compliant-wall pressure term |S| p'/α implicit in the projection (the added-mass operator in the fluid's own response); Dirichlet bit for bit when off; MMS pin on the skewed annulus (orders 2.46/2.13 at α = 10 and 100 μ/h, the Dirichlet values; a 1e12 wall reproduces Dirichlet to 2e-6); OversetPisoSolver::patch_mut; harness knob RTX_FSI2O_ROBIN_ALPHA with the previous pass's tractions as the datum, printed in the header

Co-Authored-By: Claude Fable 5.1 <[email protected]>
Claude-Session: https://claude.ai/code/session_01YJPeT6WA2e7YvAnS875AHL

crates/specialized/rtx-cfd/src/solvers/incompressible/embedded/projection.rs

@@ -4,12 +4,12 @@
 //! meshes before applying the correction once.
 
 use super::EmbeddedPisoSolver;
-use crate::CfdResult;
 use crate::solvers::incompressible::ale::SideBoundary;
 use crate::solvers::incompressible::poisson::{
-    MultigridParameters, PoissonProblem, PoissonSolverKind, solve_multigrid_pcg,
+    solve_multigrid_pcg, MultigridParameters, PoissonProblem, PoissonSolverKind,
 };
 use crate::solvers::incompressible::{EmbeddedMask, FlowField};
+use crate::CfdResult;
 
 impl EmbeddedPisoSolver {
     /// The pressure-correction system of one projection as a
@@ -337,28 +337,44 @@ impl EmbeddedPisoSolver {
                         // prescribed: a domain side with velocity data, or a
                         // non-fluid interior face.
                         let ae = if i + 1 == nx {
-                            if b.right == outlet { ae_outlet } else { 0.0 }
+                            if b.right == outlet {
+                                ae_outlet
+                            } else {
+                                0.0
+                            }
                         } else if self.u_is_fluid(j, i + 1) {
                             ae_interior
                         } else {
                             0.0
                         };
                         let aw = if i == 0 {
-                            if b.left == outlet { ae_outlet } else { 0.0 }
+                            if b.left == outlet {
+                                ae_outlet
+                            } else {
+                                0.0
+                            }
                         } else if self.u_is_fluid(j, i) {
                             ae_interior
                         } else {
                             0.0
                         };
                         let an = if j + 1 == ny {
-                            if b.top == outlet { an_outlet } else { 0.0 }
+                            if b.top == outlet {
+                                an_outlet
+                            } else {
+                                0.0
+                            }
                         } else if self.v_is_fluid(j + 1, i) {
                             an_interior
                         } else {
                             0.0
                         };
                         let as_ = if j == 0 {
-                            if b.bottom == outlet { an_outlet } else { 0.0 }
+                            if b.bottom == outlet {
+                                an_outlet
+                            } else {
+                                0.0
+                            }
                         } else if self.v_is_fluid(j, i) {
                             an_interior
                         } else {