embedded3 item 12: the DFG 3D-2Z device driver (loads by both routes, Δp, settle criterion, CSV) and the VTK instant export

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

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

@@ -0,0 +1,55 @@
+//! VTK legacy `STRUCTURED_POINTS` export of an instant: cell-centred
+//! velocity (face values averaged), pressure, and the fluid fraction /
+//! mask (1 fluid, 0 solid) — for ParaView and the viewer's 3D wake.
+
+use super::field::Field;
+use super::wall::Mask;
+use std::io::{BufWriter, Write};
+
+/// Write `field` (and the mask's fluid fraction when given) at `path`.
+pub fn write_vtk(
+    path: &std::path::Path,
+    field: &Field,
+    mask: Option<&Mask>,
+) -> std::io::Result<()> {
+    let g = field.grid;
+    let (nx, ny, nz) = (g.nx, g.ny, g.nz);
+    let mut out = BufWriter::new(std::fs::File::create(path)?);
+    writeln!(out, "# vtk DataFile Version 3.0")?;
+    writeln!(out, "embedded3 instant")?;
+    writeln!(out, "ASCII")?;
+    writeln!(out, "DATASET STRUCTURED_POINTS")?;
+    writeln!(out, "DIMENSIONS {nx} {ny} {nz}")?;
+    writeln!(out, "ORIGIN {} {} {}", 0.5 * g.dx, 0.5 * g.dy, 0.5 * g.dz)?;
+    writeln!(out, "SPACING {} {} {}", g.dx, g.dy, g.dz)?;
+    writeln!(out, "POINT_DATA {}", g.cells())?;
+    writeln!(out, "VECTORS velocity double")?;
+    for k in 0..nz {
+        for j in 0..ny {
+            for i in 0..nx {
+                let uc = 0.5 * (field.u[g.uface(k, j, i)] + field.u[g.uface(k, j, i + 1)]);
+                let vc = 0.5 * (field.v[g.vface(k, j, i)] + field.v[g.vface(k, j + 1, i)]);
+                let wc = 0.5 * (field.w[g.wface(k, j, i)] + field.w[g.wface(k + 1, j, i)]);
+                writeln!(out, "{uc:.6e} {vc:.6e} {wc:.6e}")?;
+            }
+        }
+    }
+    writeln!(out, "SCALARS pressure double 1")?;
+    writeln!(out, "LOOKUP_TABLE default")?;
+    for &p in &field.p {
+        writeln!(out, "{p:.6e}")?;
+    }
+    if let Some(m) = mask {
+        writeln!(out, "SCALARS fluid double 1")?;
+        writeln!(out, "LOOKUP_TABLE default")?;
+        for idx in 0..g.cells() {
+            let f = if m.is_fluid_cell(idx) {
+                m.vol(idx)
+            } else {
+                0.0
+            };
+            writeln!(out, "{f:.4}")?;
+        }
+    }
+    out.flush()
+}

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

@@ -9,6 +9,7 @@
 pub mod body;
 pub mod cut;
 pub mod cutwall;
+pub mod export_vtk;
 pub mod field;
 pub mod grid;
 pub mod impose;
@@ -19,6 +20,7 @@ pub mod wall;
 
 pub use body::{Body, SurfaceSample};
 pub use cut::CutGeometry;
+pub use export_vtk::write_vtk;
 pub use field::Field;
 pub use grid::Grid;
 pub use loads::SurfaceForce;