Omar SobhandClaude Opus 5.5
74fac32a91
- tests/fsi2_embedded3_impulse.rs (new, ignored, cuda): the added-mass timing instrument — the R8-a fluid with a prescribed centreline velocity step (a one-step acceleration delta), baseline and impulse passes from one device snapshot, the load difference per step. Pitch shape on the slab ny 62: generalized added mass 39.11 / 39.09 / 39.07 kg/m at dt x 1 / 0.75 / 0.5, the step after carries 1.7 / 1.3 / 0.9 % above the steady tail — the cut-cell fluid answers in the same step (the lagged-added-mass hypothesis refuted). - fsi2_embedded3.rs: `RTX_E3FSI_LINE_CSV` (per-step centreline + mid/bottom/top y per station) showed the growing 2dt mode is a through-thickness mode — the edge nodes move against the mid-plane nodes (~4:1): the fluid reads the mid-plane, the loads land on the edges, so the added mass acts on that mode with the wrong sign (a negative effective added mass; the scalar Newmark model is unstable for it at omega dt below ~1-2 with gamma 0.7, stable at larger dt or gamma 0.9 — R8-a's observed pattern). `RTX_E3FSI_KIN=surface` (default off, byte-identical when unset): the fluid's centreline = the mean of the bottom and top edge nodes (the nodes the loads land on) — dt x 0.75 / 0.5 / 0.25 stable at gamma 0.7. Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>
733 lines
28 KiB
Rust
733 lines
28 KiB
Rust
//! R8-a: the first coupled 3D FSI — the embedded3 cut-cell fluid (device
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//! path) coupled to the 2D Turek–Hron flag (rtx-fea 35×2 Quad8 SVK, total
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//! Lagrangian, Newmark γ 0.7) under a SPAN-UNIFORM deformation: the
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//! structure's centreline drives the 3D body's polyline each coupled step,
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//! the fluid's operator-route wall load, integrated over the span per unit
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//! width, loads the structure's wetted nodes. Partitioned: per coupled
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//! step the fluid re-runs the same step from a device snapshot for each
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//! Aitken subiteration (the overset harness's pattern; `DeviceStep::
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//! snapshot / restore`).
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//!
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//! The body is the embedded flag test's capsule (a semicircular tip, apex
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//! on A): its 2D counterpart is the overset's SEMICIRCLE line (P5-2 ny 62:
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//! 94.8 mm at 1.914 Hz), not the flat/1.25 mm-corner reference line.
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//!
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//! Knobs `RTX_E3FSI_*`: `NY` (62), `NZ` (4 = the periodic slab; 0 = the
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//! full 0.41 m duct with slip sides), `T_RIGID` (3.0 s of rigid flag),
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//! `T_END` (13.0), `RIGID_ONLY` (1 = stop after the rigid phase: target 1),
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//! `RTOL` (1e-3), `FLOOR` (1.5e-7 on the centreline vector), `MAX_SUBIT`
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//! (12), `STALL_ACCEPT` (5), `GAMMA` (0.7), `SPEED` (3.0 m/s, the band's
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//! surface-speed bound), `CSV` (per-step series), `TRACE` (steps whose
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//! passes are printed); R8-e: `KIN` (`centre` = the mid-plane nodes drive
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//! the fluid's centreline; `surface` = the mean of the bottom and top edge
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//! nodes, the nodes the loads land on — the transfer-consistent pair that
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//! removes the small-dt instability), `LINE_CSV` (the committed centreline
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//! and the per-station mid/bottom/top y displacement per step).
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//!
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//! `RTX_E3FSI_NY=62 RTX_E3FSI_CSV=<path> RTX_CUDA_ARCH=sm_120 cargo test --release -p rtx-fsi \
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//! --features cuda --test fsi2_embedded3 -- --ignored --nocapture`
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#![cfg(feature = "cuda")]
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#[path = "fsi2_embedded3/fluid.rs"]
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mod fluid;
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#[path = "fsi2_harness/mod.rs"]
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mod fsi2_harness;
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#[path = "fsi2_embedded3/state.rs"]
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mod state;
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use std::cell::RefCell;
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use std::io::Write as _;
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use fluid::{CX, CY, Contribution, E3Fluid, HALF, Line, R_CYL};
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use fsi2_harness::{FSI2, Interface, clamp_left, flag_mesh, median, mid_amp};
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use nalgebra::{DVector, Vector3};
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use rtx_fea::analysis::{
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AnalysisConfig, ConvergenceCriteria, DynamicState, NonlinearDynamicAnalysis,
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};
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use rtx_fea::materials::{LinearElastic, MaterialDatabase};
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use rtx_fea::mesh::{MaterialId, Mesh, NodeId};
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use rtx_fsi::Subiterated;
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pub fn env_f(name: &str, default: f64) -> f64 {
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std::env::var(name)
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.ok()
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.and_then(|v| v.parse().ok())
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.unwrap_or(default)
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}
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const X0: f64 = 0.25;
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/// Centreline stations: the element corners at x 0.25, 0.26, …, 0.59 (the
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/// last 10 mm is the capsule's cap).
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const STATIONS: usize = 35;
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/// The flag's structure-side bookkeeping: the centreline nodes, the wetted
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/// edges with their reference coordinates, the tip node A.
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struct Flag {
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centre: Vec<NodeId>,
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interface: Interface,
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/// (reference x, wetted index or None for the clamp corner), ascending.
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bottom: Vec<(f64, Option<usize>)>,
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top: Vec<(f64, Option<usize>)>,
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/// (reference y, wetted index), ascending (corners included).
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tip: Vec<(f64, usize)>,
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a_node: NodeId,
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/// R8-e: the bottom and top edge nodes at each station's x (the wetted
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/// surface the loads land on).
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surface: Vec<[NodeId; 2]>,
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}
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impl Flag {
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fn build(mesh: &Mesh) -> Self {
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let find = |x: f64, y: f64| -> NodeId {
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*mesh
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.nodes
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.iter()
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.find(|(_, n)| {
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let p = n.position();
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(p.x - x).abs() < 1e-9 && (p.y - y).abs() < 1e-9
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})
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.expect("node")
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.0
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};
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let centre = (0..STATIONS)
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.map(|k| find(X0 + 0.01 * k as f64, 0.2))
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.collect();
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let interface = Interface::build(mesh);
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let edge = |idx: &[usize]| -> Vec<(f64, Option<usize>)> {
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let mut v: Vec<(f64, Option<usize>)> = vec![(X0, None)];
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v.extend(idx.iter().map(|&k| (interface.reference[k].0, Some(k))));
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v.sort_by(|a, b| a.0.partial_cmp(&b.0).unwrap());
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v
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};
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let bottom = edge(&interface.bottom);
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let top = edge(&interface.top);
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let mut tip: Vec<(f64, usize)> = interface
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.tip
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.iter()
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.map(|&k| (interface.reference[k].1, k))
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.collect();
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tip.sort_by(|a, b| a.0.partial_cmp(&b.0).unwrap());
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Self {
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centre,
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interface,
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bottom,
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top,
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tip,
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a_node: find(0.6, 0.2),
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surface: (0..STATIONS)
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.map(|k| {
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let x = X0 + 0.01 * k as f64;
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[find(x, 0.19), find(x, 0.21)]
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})
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.collect(),
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}
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}
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}
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/// Linear split of `value` at `s` over sorted stations; the share of a
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/// `None` station (the clamp) is dropped.
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fn split<T: Copy>(stations: &[(f64, T)], s: f64, value: f64, mut add: impl FnMut(T, f64)) {
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let n = stations.len();
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let s = s.clamp(stations[0].0, stations[n - 1].0);
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let m = stations.partition_point(|st| st.0 < s).clamp(1, n - 1);
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let (a, b) = (stations[m - 1], stations[m]);
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let u = if b.0 > a.0 {
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(s - a.0) / (b.0 - a.0)
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} else {
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0.0
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};
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add(a.1, (1.0 - u) * value);
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add(b.1, u * value);
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}
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/// The operator route's contributions onto the wetted nodes (per unit
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/// span): each is placed by its closest point on the fluid's centreline —
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/// the top or bottom edge at the same arc position, or the tip edge by its
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/// lateral offset beyond the last station. Returns the nodal loads, the
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/// flag's (fx, fy) and the cylinder's (fx, fy) per span, and the flag's fy
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/// by part (pressure, shear, diffusive and convective exchange).
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/// `RTX_E3FSI_PARTS` (bit mask, default 15 = all) keeps parts off the
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/// structure (a diagnostic; the reported loads keep every part).
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fn distribute(
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flag: &Flag,
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line: &Line,
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contributions: &[Contribution],
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width: f64,
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) -> (Vec<(NodeId, Vector3<f64>)>, [f64; 2], [f64; 2], [f64; 4]) {
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let nw = flag.interface.wetted.len();
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let mut f = vec![[0.0f64; 2]; nw];
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let (mut on_flag, mut on_cyl) = ([0.0f64; 2], [0.0f64; 2]);
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let mut parts_y = [0.0f64; 4];
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let pts = &line.pts;
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let mut cum = vec![0.0; pts.len()];
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for m in 1..pts.len() {
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cum[m] = cum[m - 1]
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+ ((pts[m][0] - pts[m - 1][0]).powi(2) + (pts[m][1] - pts[m - 1][1]).powi(2)).sqrt();
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}
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let parts_on = env_f("RTX_E3FSI_PARTS", 15.0) as usize;
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for &(pos, c, part, v) in contributions {
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if c > 1 {
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continue;
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}
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let v = v / width;
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let (x, y) = (pos[0], pos[1]);
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let mut best = (f64::INFINITY, 0usize, 0.0f64);
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for m in 0..pts.len() - 1 {
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let (a, b) = (pts[m], pts[m + 1]);
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let (ex, ey) = (b[0] - a[0], b[1] - a[1]);
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let l2 = ex * ex + ey * ey;
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let u = (((x - a[0]) * ex + (y - a[1]) * ey) / l2).clamp(0.0, 1.0);
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let d = ((x - a[0] - u * ex).powi(2) + (y - a[1] - u * ey).powi(2)).sqrt();
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if d < best.0 {
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best = (d, m, u);
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}
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}
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let d_cyl = ((x - CX).powi(2) + (y - CY).powi(2)).sqrt() - R_CYL;
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if d_cyl < best.0 - HALF {
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on_cyl[c] += v;
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continue;
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}
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on_flag[c] += v;
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if c == 1 {
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parts_y[part] += v;
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}
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if parts_on & (1 << part) == 0 {
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continue;
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}
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let (_, m, u) = best;
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let (a, b) = (pts[m], pts[m + 1]);
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let (ex, ey) = (b[0] - a[0], b[1] - a[1]);
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let len = (ex * ex + ey * ey).sqrt();
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let (tx, ty) = (ex / len, ey / len);
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let (px, py) = (a[0] + u * ex, a[1] + u * ey);
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// Lateral offset: + on the upper side of the centreline.
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let eta = tx * (y - py) - ty * (x - px);
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let along = tx * (x - px) + ty * (y - py);
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let mut add = |k: usize, w: f64| f[k][c] += w;
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if m + 2 == pts.len() && u >= 1.0 && along > 0.0 {
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let yr = 0.2 + eta.clamp(-HALF, HALF);
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split(&flag.tip, yr, v, &mut add);
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} else {
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let xr = X0 + cum[m] + u * len;
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let edge = if eta >= 0.0 { &flag.top } else { &flag.bottom };
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split(edge, xr, v, |k, w| {
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if let Some(k) = k {
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add(k, w);
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}
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});
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}
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}
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let nodal = flag
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.interface
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.wetted
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.iter()
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.zip(&f)
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.map(|(&id, v)| (id, Vector3::new(v[0], v[1], 0.0)))
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.collect();
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(nodal, on_flag, on_cyl, parts_y)
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}
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/// The fluid's centreline from the structure's centreline displacement `c`
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/// (2 per station) with velocities `(c − c_prev) / dt`.
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fn line_of(t: f64, c: &[f64], c_prev: &[f64], dt: f64) -> Line {
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let pts = (0..STATIONS)
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.map(|k| [X0 + 0.01 * k as f64 + c[2 * k], 0.2 + c[2 * k + 1]])
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.collect();
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let vel = (0..STATIONS)
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.map(|k| {
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[
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(c[2 * k] - c_prev[2 * k]) / dt,
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(c[2 * k + 1] - c_prev[2 * k + 1]) / dt,
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]
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})
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.collect();
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Line { t, pts, vel }
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}
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#[test]
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#[ignore = "R8-a: the coupled FSI2 on embedded3 (GPU; minutes to hours)"]
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fn fsi2_on_embedded3() {
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let ny = env_f("RTX_E3FSI_NY", 62.0) as usize;
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let nz = env_f("RTX_E3FSI_NZ", 4.0) as usize;
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let t_rigid = env_f("RTX_E3FSI_T_RIGID", 3.0);
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let t_end = env_f("RTX_E3FSI_T_END", 13.0);
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let rigid_only = env_f("RTX_E3FSI_RIGID_ONLY", 0.0) > 0.5;
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let rtol = env_f("RTX_E3FSI_RTOL", 1e-3);
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let floor = env_f("RTX_E3FSI_FLOOR", 1.5e-7);
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let max_subit = env_f("RTX_E3FSI_MAX_SUBIT", 12.0) as usize;
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let stall_accept = env_f("RTX_E3FSI_STALL_ACCEPT", 5.0);
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let gamma = env_f("RTX_E3FSI_GAMMA", 0.7);
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let speed = env_f("RTX_E3FSI_SPEED", 3.0);
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let trace = env_f("RTX_E3FSI_TRACE", 0.0) as usize;
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let csv_path = std::env::var("RTX_E3FSI_CSV").ok();
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let restore_check = env_f("RTX_E3FSI_RESTORE_CHECK", 0.0) as usize;
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let case = FSI2;
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let mesh = flag_mesh(35, 2);
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let flag_geo = Flag::build(&mesh);
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let zero_c = vec![0.0; 2 * STATIONS];
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let rest = line_of(0.0, &zero_c, &zero_c, 1.0);
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// `RTX_E3FSI_LOAD=<dir>`: continue from a saved coupled state (extruded
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// onto the full duct when the saved nz differs); `RTX_E3FSI_SAVE=<dir>`
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// saves the state every `RTX_E3FSI_SAVE_EVERY` coupled steps (2000) and at the end.
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let saved = std::env::var("RTX_E3FSI_LOAD")
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.ok()
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.map(|d| state::Saved::load(&d).expect("load the saved state"));
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let save_dir = std::env::var("RTX_E3FSI_SAVE").ok();
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let save_every = env_f("RTX_E3FSI_SAVE_EVERY", 2000.0) as usize;
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let mut fl = E3Fluid::build(ny, nz, speed, rest.clone(), saved.as_ref());
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if let Some(s) = &saved {
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println!(
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" loaded the coupled state at t {:.4} from {} ({}×{}×{} → nz {})",
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s.t,
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std::env::var("RTX_E3FSI_LOAD").unwrap(),
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s.dims[0],
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s.dims[1],
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s.dims[2],
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fl.grid.nz
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);
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}
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let dt = fl.dt;
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println!(
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" R8-a FSI2 on embedded3: rigid to {t_rigid} s, coupled to {t_end} s; Aitken rtol {rtol:.1e} floor {floor:.1e} max {max_subit} stall accept {stall_accept}; Newmark γ {gamma}; the body's 2D counterpart = the overset SEMICIRCLE line (ny 62: 94.8 mm, 1.914 Hz)"
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);
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let mut csv = csv_path.as_ref().map(|p| {
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let mut f = std::fs::File::create(p).expect("csv");
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writeln!(
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f,
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"t,phase,ux,uy,drag,lift,drag_flag,lift_flag,subit,dres,residual,cg,fresh,sink_dx,sink_dy,lift_p,lift_shear,lift_xdiff,lift_xconv"
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)
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.unwrap();
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f
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});
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// R8-e `RTX_E3FSI_LINE_CSV`: the committed centreline per coupled step
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// (t, then x, y displacement per station) — the unstable mode's shape.
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let mut line_csv = std::env::var("RTX_E3FSI_LINE_CSV")
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.ok()
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.map(|p| std::fs::File::create(p).expect("line csv"));
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let start = std::time::Instant::now();
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// Phase 1: the rigid flag (target 1: the rest state vs CFD2 136.7 / 10.53).
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let rigid_steps = if saved.is_some() {
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0
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} else {
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(t_rigid / dt).round() as usize
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};
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let mut last = ([0.0; 3], Vec::new());
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for step in 0..rigid_steps {
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let r = fl.step();
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assert!(r.final_residual.is_finite(), "rigid death at step {step}");
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if (step + 1) % 50 == 0 || step + 1 == rigid_steps {
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last = fl.loads();
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let (tot, contrib) = &last;
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let (_, on_flag, on_cyl, _) = distribute(&flag_geo, &rest, contrib, fl.load_width);
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let t = fl.time();
|
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if let Some(f) = csv.as_mut() {
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writeln!(
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f,
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"{t:.6},rigid,0,0,{:.5},{:.5},{:.5},{:.5},0,0,{:.3e},{},{},{:.3e},{:.3e},,,,",
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tot[0],
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tot[1],
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on_flag[0],
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on_flag[1],
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r.final_residual,
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r.poisson_iterations,
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r.fresh_cells,
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on_flag[0] + on_cyl[0] - tot[0],
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on_flag[1] + on_cyl[1] - tot[1]
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)
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.unwrap();
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}
|
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if (step + 1) % 500 == 0 || step + 1 == rigid_steps {
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println!(
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" rigid t {t:.3}: drag/span {:.2} lift/span {:+.2} (flag {:.2} {:+.2}, cylinder {:.2} {:+.2}); residual {:.1e}, CG {}; [{:.0} s]",
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tot[0],
|
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tot[1],
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on_flag[0],
|
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on_flag[1],
|
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on_cyl[0],
|
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on_cyl[1],
|
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r.final_residual,
|
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r.poisson_iterations,
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start.elapsed().as_secs_f64()
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);
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}
|
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}
|
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}
|
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let (tot0, contrib0) = last;
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println!(
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" RIGID ny {ny} nz {nz} at t {:.3}: drag/span {:.2} (CFD2 136.7), lift/span {:+.2} (CFD2 10.53); {rigid_steps} steps in {:.0} s",
|
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fl.time(),
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tot0[0],
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tot0[1],
|
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start.elapsed().as_secs_f64()
|
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);
|
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if rigid_only && saved.is_none() {
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return;
|
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}
|
||
|
||
// The structure: FSI2's flag at the coupled step dt.
|
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let mut db = MaterialDatabase::new();
|
||
db.add_material(
|
||
MaterialId(0),
|
||
LinearElastic::new(case.e_s, case.nu_s).with_density(case.rho_s),
|
||
None,
|
||
);
|
||
let beta = (gamma + 0.5).powi(2) / 4.0;
|
||
let analysis = NonlinearDynamicAnalysis::new(
|
||
mesh.clone(),
|
||
db,
|
||
clamp_left(&mesh),
|
||
dt,
|
||
1,
|
||
AnalysisConfig::default(),
|
||
)
|
||
.with_total_lagrangian()
|
||
.with_convergence_criteria(ConvergenceCriteria {
|
||
max_iterations: 60,
|
||
..ConvergenceCriteria::default()
|
||
})
|
||
.with_newmark_parameters(gamma, beta);
|
||
let flag = RefCell::new(analysis.stepper().unwrap());
|
||
let centre_dofs: Vec<[usize; 2]> = flag_geo
|
||
.centre
|
||
.iter()
|
||
.map(|&id| {
|
||
let d = flag.borrow().node_dofs(id);
|
||
[d[0], d[1]]
|
||
})
|
||
.collect();
|
||
let a_dofs = flag.borrow().node_dofs(flag_geo.a_node);
|
||
// R8-e `RTX_E3FSI_KIN=surface`: the fluid's centreline is the mean of the
|
||
// bottom and top edge nodes at each station (the nodes the loads land on)
|
||
// instead of the mid-plane nodes (default `centre`).
|
||
let kin_surface = std::env::var("RTX_E3FSI_KIN").is_ok_and(|v| v == "surface");
|
||
let surface_dofs: Vec<[usize; 4]> = flag_geo
|
||
.surface
|
||
.iter()
|
||
.map(|[b, t]| {
|
||
let (db, dt_) = (flag.borrow().node_dofs(*b), flag.borrow().node_dofs(*t));
|
||
[db[0], db[1], dt_[0], dt_[1]]
|
||
})
|
||
.collect();
|
||
let extract = |s: &DynamicState| -> Vec<f64> {
|
||
let mut c = vec![0.0; 2 * STATIONS];
|
||
if kin_surface {
|
||
for (k, d) in surface_dofs.iter().enumerate() {
|
||
c[2 * k] = 0.5 * (s.displacement[d[0]] + s.displacement[d[2]]);
|
||
c[2 * k + 1] = 0.5 * (s.displacement[d[1]] + s.displacement[d[3]]);
|
||
}
|
||
return c;
|
||
}
|
||
for (k, d) in centre_dofs.iter().enumerate() {
|
||
c[2 * k] = s.displacement[d[0]];
|
||
c[2 * k + 1] = s.displacement[d[1]];
|
||
}
|
||
c
|
||
};
|
||
|
||
let (mut flag_state, mut committed_nodal, mut line_n, mut c_fluid_n) = match &saved {
|
||
Some(s) => {
|
||
let nodal: Vec<(NodeId, Vector3<f64>)> = flag_geo
|
||
.interface
|
||
.wetted
|
||
.iter()
|
||
.enumerate()
|
||
.map(|(k, &id)| (id, Vector3::new(s.nodal[2 * k], s.nodal[2 * k + 1], 0.0)))
|
||
.collect();
|
||
let state = DynamicState {
|
||
displacement: DVector::from_vec(s.disp.clone()),
|
||
velocity: DVector::from_vec(s.vel.clone()),
|
||
acceleration: DVector::from_vec(s.acc.clone()),
|
||
};
|
||
(state, nodal, s.line.clone(), s.c_fluid.clone())
|
||
}
|
||
None => {
|
||
let (nodal0, _, _, _) = distribute(&flag_geo, &rest, &contrib0, fl.load_width);
|
||
flag.borrow_mut().set_nodal_forces(&nodal0);
|
||
let state = flag.borrow_mut().rest_state().unwrap();
|
||
// The fluid's own previous line and centreline (its geometry's history).
|
||
let line = Line {
|
||
t: fl.time(),
|
||
..rest.clone()
|
||
};
|
||
(state, nodal0, line, zero_c.clone())
|
||
}
|
||
};
|
||
|
||
let coupled_steps = ((t_end - fl.time()) / dt).round() as usize;
|
||
let fl = RefCell::new(fl);
|
||
let (mut times, mut uy_series, mut ux_series) = (Vec::new(), Vec::new(), Vec::new());
|
||
let (mut drag_s, mut lift_s) = (Vec::new(), Vec::new());
|
||
let (mut total_subit, mut max_seen, mut stalled) = (0usize, 0usize, 0usize);
|
||
let mut death: Option<String> = None;
|
||
let t_fluid = std::cell::Cell::new(0.0f64);
|
||
let t_restore = std::cell::Cell::new(0.0f64);
|
||
let t_loads = std::cell::Cell::new(0.0f64);
|
||
let t_struct = std::cell::Cell::new(0.0f64);
|
||
let phase_start = std::time::Instant::now();
|
||
for step in 0..coupled_steps {
|
||
let t_old = fl.borrow().time();
|
||
let t_new = t_old + dt;
|
||
let predicted = {
|
||
flag.borrow_mut().set_nodal_forces(&committed_nodal);
|
||
let (p, _) = flag.borrow_mut().step(&flag_state).unwrap();
|
||
extract(&p)
|
||
};
|
||
let c_struct_n = extract(&flag_state);
|
||
let snap = fl.borrow_mut().snapshot();
|
||
let dirty = std::cell::Cell::new(false);
|
||
type Pass = (
|
||
DynamicState,
|
||
Vec<(NodeId, Vector3<f64>)>,
|
||
Line,
|
||
Vec<f64>,
|
||
[f64; 3],
|
||
[f64; 2],
|
||
fluid_step::Stats,
|
||
);
|
||
let latest: RefCell<Option<Pass>> = RefCell::new(None);
|
||
let pass = |cand: &[f64]| -> Vec<f64> {
|
||
let line = line_of(t_new, cand, &c_fluid_n, dt);
|
||
let mut f = fl.borrow_mut();
|
||
let tr = std::time::Instant::now();
|
||
f.set_lines(line_n.clone(), line.clone());
|
||
if dirty.get() {
|
||
f.restore(&snap);
|
||
}
|
||
dirty.set(true);
|
||
t_restore.set(t_restore.get() + tr.elapsed().as_secs_f64());
|
||
let tf = std::time::Instant::now();
|
||
let r = f.step();
|
||
t_fluid.set(t_fluid.get() + tf.elapsed().as_secs_f64());
|
||
if !r.final_residual.is_finite() {
|
||
return vec![f64::NAN; cand.len()];
|
||
}
|
||
let tl = std::time::Instant::now();
|
||
let (tot, contrib) = f.loads();
|
||
let (nodal, on_flag, on_cyl, parts_y) =
|
||
distribute(&flag_geo, &line, &contrib, f.load_width);
|
||
t_loads.set(t_loads.get() + tl.elapsed().as_secs_f64());
|
||
let ts = std::time::Instant::now();
|
||
let mut st = flag.borrow_mut();
|
||
st.set_nodal_forces(&nodal);
|
||
let (new_state, _) = st.step(&flag_state).unwrap();
|
||
t_struct.set(t_struct.get() + ts.elapsed().as_secs_f64());
|
||
let out = extract(&new_state);
|
||
if step < trace {
|
||
let res: f64 = out
|
||
.iter()
|
||
.zip(cand)
|
||
.map(|(a, b)| (a - b).powi(2))
|
||
.sum::<f64>()
|
||
.sqrt();
|
||
println!(
|
||
" step {step} pass: |c_new − c_cand| {res:.3e}, tip cand ({:+.4e}, {:+.4e}), load flag ({:+.3}, {:+.3}) cyl ({:+.3}, {:+.3}) total ({:+.3}, {:+.3}), residual {:.1e}, fresh {}",
|
||
cand[2 * STATIONS - 2],
|
||
cand[2 * STATIONS - 1],
|
||
on_flag[0],
|
||
on_flag[1],
|
||
on_cyl[0],
|
||
on_cyl[1],
|
||
tot[0],
|
||
tot[1],
|
||
r.final_residual,
|
||
r.fresh_cells
|
||
);
|
||
}
|
||
let stats = fluid_step::Stats {
|
||
residual: r.final_residual,
|
||
cg: r.poisson_iterations,
|
||
fresh: r.fresh_cells,
|
||
sink: [
|
||
on_flag[0] + on_cyl[0] - tot[0],
|
||
on_flag[1] + on_cyl[1] - tot[1],
|
||
],
|
||
parts_y,
|
||
};
|
||
*latest.borrow_mut() =
|
||
Some((new_state, nodal, line, cand.to_vec(), tot, on_flag, stats));
|
||
out
|
||
};
|
||
let increment: f64 = predicted
|
||
.iter()
|
||
.zip(&c_struct_n)
|
||
.map(|(a, b)| (a - b).powi(2))
|
||
.sum::<f64>()
|
||
.sqrt();
|
||
let tol = floor.max(rtol * increment);
|
||
let acceptable = (stall_accept * tol).max(0.1 * increment);
|
||
let outcome = Subiterated::aitken(max_subit, tol)
|
||
.unwrap()
|
||
.solve(&predicted, &pass);
|
||
// `RTX_E3FSI_RESTORE_CHECK=N`: on the first N steps, the accepted
|
||
// candidate re-run from the snapshot (the restore's repeatability).
|
||
if step < restore_check && outcome.is_ok() {
|
||
let (cand, tot_a, out_a) = {
|
||
let l = latest.borrow();
|
||
let l = l.as_ref().expect("a pass ran");
|
||
(l.3.clone(), l.4, extract(&l.0))
|
||
};
|
||
let out_b = pass(&cand);
|
||
let tot_b = latest.borrow().as_ref().expect("re-run").4;
|
||
let dout: f64 = out_a
|
||
.iter()
|
||
.zip(&out_b)
|
||
.map(|(a, b)| (a - b).powi(2))
|
||
.sum::<f64>()
|
||
.sqrt();
|
||
println!(
|
||
" RESTORE CHECK step {step}: load a ({:+.9e}, {:+.9e}) b ({:+.9e}, {:+.9e}), |Δ structure output| {dout:.3e}",
|
||
tot_a[0], tot_a[1], tot_b[0], tot_b[1]
|
||
);
|
||
}
|
||
let (iters, dres) = match outcome {
|
||
Ok(c) => (c.iterations, c.residual),
|
||
Err(
|
||
rtx_fsi::FsiError::CouplingNotConverged {
|
||
iterations,
|
||
residual,
|
||
..
|
||
}
|
||
| rtx_fsi::FsiError::CouplingDiverged {
|
||
iterations,
|
||
residual,
|
||
},
|
||
) if residual < acceptable => {
|
||
stalled += 1;
|
||
(iterations, residual)
|
||
}
|
||
Err(e) => {
|
||
println!(
|
||
" R8-a DEATH at coupled step {step} t = {t_new:.4}: {e:?} (increment {increment:.3e}, tol {tol:.3e}, acceptable {acceptable:.3e})"
|
||
);
|
||
death = Some(format!("step {step} t {t_new:.4}: {e:?}"));
|
||
break;
|
||
}
|
||
};
|
||
total_subit += iters;
|
||
max_seen = max_seen.max(iters);
|
||
let (new_state, nodal, line, cand, tot, on_flag, stats) =
|
||
latest.borrow_mut().take().expect("a pass ran");
|
||
flag_state = new_state;
|
||
committed_nodal = nodal;
|
||
line_n = line;
|
||
c_fluid_n = cand;
|
||
let ux = flag_state.displacement[a_dofs[0]];
|
||
let uy = flag_state.displacement[a_dofs[1]];
|
||
times.push(t_new);
|
||
ux_series.push(ux);
|
||
uy_series.push(uy);
|
||
drag_s.push(tot[0]);
|
||
lift_s.push(tot[1]);
|
||
if let Some(f) = csv.as_mut() {
|
||
writeln!(
|
||
f,
|
||
"{t_new:.6},coupled,{ux:.6e},{uy:.6e},{:.5},{:.5},{:.5},{:.5},{iters},{dres:.3e},{:.3e},{},{},{:.3e},{:.3e},{:.4},{:.4},{:.4},{:.4}",
|
||
tot[0],
|
||
tot[1],
|
||
on_flag[0],
|
||
on_flag[1],
|
||
stats.residual,
|
||
stats.cg,
|
||
stats.fresh,
|
||
stats.sink[0],
|
||
stats.sink[1],
|
||
stats.parts_y[0],
|
||
stats.parts_y[1],
|
||
stats.parts_y[2],
|
||
stats.parts_y[3]
|
||
)
|
||
.unwrap();
|
||
}
|
||
if let Some(f) = line_csv.as_mut() {
|
||
// Then the y displacement of the mid-plane, bottom and top nodes per station.
|
||
let mut c: Vec<String> = c_fluid_n.iter().map(|v| format!("{v:.6e}")).collect();
|
||
for (k, d) in surface_dofs.iter().enumerate() {
|
||
let yc = flag_state.displacement[centre_dofs[k][1]];
|
||
let (yb, yt) = (flag_state.displacement[d[1]], flag_state.displacement[d[3]]);
|
||
c.extend([yc, yb, yt].map(|v| format!("{v:.6e}")));
|
||
}
|
||
writeln!(f, "{t_new:.6},{}", c.join(",")).unwrap();
|
||
}
|
||
let at_end = step + 1 == coupled_steps;
|
||
if let Some(dir) = save_dir
|
||
.as_ref()
|
||
.filter(|_| at_end || (step + 1) % save_every == 0)
|
||
{
|
||
let f = fl.borrow();
|
||
let g = f.grid;
|
||
state::Saved {
|
||
t: t_new,
|
||
dims: [g.nx, g.ny, g.nz],
|
||
h: f.h,
|
||
u: f.field.u.clone(),
|
||
v: f.field.v.clone(),
|
||
w: f.field.w.clone(),
|
||
p: f.field.p.clone(),
|
||
disp: flag_state.displacement.as_slice().to_vec(),
|
||
vel: flag_state.velocity.as_slice().to_vec(),
|
||
acc: flag_state.acceleration.as_slice().to_vec(),
|
||
line: line_n.clone(),
|
||
c_fluid: c_fluid_n.clone(),
|
||
nodal: committed_nodal
|
||
.iter()
|
||
.flat_map(|(_, v)| [v.x, v.y])
|
||
.collect(),
|
||
}
|
||
.save(dir)
|
||
.expect("save the coupled state");
|
||
}
|
||
if (step + 1) % 250 == 0 {
|
||
let w = &uy_series[uy_series.len().saturating_sub(600)..];
|
||
let (mid, amp) = mid_amp(w);
|
||
println!(
|
||
" t {t_new:.3} ({} steps): uy(A) {uy:+.4e} ux {ux:+.4e} (last ~1 period mid {mid:+.3e} amp {amp:.3e}), drag {:.1} lift {:+.1}; {:.2} subit/step (max {max_seen}, stalled {stalled}); fluid {:.0} s restore {:.0} s loads {:.0} s structure {:.0} s of {:.0} s",
|
||
step + 1,
|
||
tot[0],
|
||
tot[1],
|
||
total_subit as f64 / (step + 1) as f64,
|
||
t_fluid.get(),
|
||
t_restore.get(),
|
||
t_loads.get(),
|
||
t_struct.get(),
|
||
phase_start.elapsed().as_secs_f64()
|
||
);
|
||
}
|
||
}
|
||
// Summary: the last two seconds (or what there is).
|
||
let n = times.len();
|
||
if n > 0 {
|
||
let t_last = times[n - 1];
|
||
let from = times.partition_point(|&t| t < t_last - 2.0);
|
||
let (mid, amp) = mid_amp(&uy_series[from..]);
|
||
let (uxm, uxa) = mid_amp(&ux_series[from..]);
|
||
let f = fsi2_harness::crossing_frequency(×[from..], &uy_series[from..]);
|
||
let mut d: Vec<f64> = drag_s[from..].to_vec();
|
||
let (dm, _) = mid_amp(&d);
|
||
let (lm, la) = mid_amp(&lift_s[from..]);
|
||
let dmed = median(&mut d);
|
||
println!(
|
||
" FINAL R8-a ny {ny} nz {nz}: {n} coupled steps to t {t_last:.3}; last 2 s: uy(A) {:.2} ± {:.2} mm, ux(A) {:.2} ± {:.2} mm, f {}, drag mid {dm:.1} (median {dmed:.1}), lift {lm:+.1} ± {la:.1}; {:.2} subit/step (max {max_seen}, stalled {stalled}); death {}; wall {:.0} s",
|
||
1e3 * mid,
|
||
1e3 * amp,
|
||
1e3 * uxm,
|
||
1e3 * uxa,
|
||
f.map_or("n/a".into(), |f| format!("{f:.4} Hz")),
|
||
total_subit as f64 / n as f64,
|
||
death.as_deref().unwrap_or("none"),
|
||
start.elapsed().as_secs_f64()
|
||
);
|
||
}
|
||
}
|
||
|
||
mod fluid_step {
|
||
pub struct Stats {
|
||
pub residual: f64,
|
||
pub cg: usize,
|
||
pub fresh: usize,
|
||
pub sink: [f64; 2],
|
||
pub parts_y: [f64; 4],
|
||
}
|
||
}
|