31 Commits

Include renames

Author	SHA1	Message	Date
Omar SobhandClaude Fable 5.1	6526a3bd38	rtx-cfd embedded3 item 1: the Poisson core as poisson/{problem, hierarchy, pcg} (≤ 385 lines each; the periodic wrap built once into neighbour arrays); gate 1 HELD: nz=1 bit-identical to the 2D solver (lex + red-black, cached/uncached, iterations) and every extrusion case bit-identical to the three_d oracle, planes within 1.4e-11 ... Co-Authored-By: Claude Fable 5.1 <[email protected]>	2026-09-17 14:50:18 -05:00
Omar SobhandClaude Fable 5.1	0794e1b6db	rtx-cfd 3D Stage 1 item 1: three_d::{Grid3, poisson} — the 2D Poisson stack transcribed to a seven-point operator (sanitised coefficients, 2×2×2 Galerkin aggregation, (i+j+k)%2 colouring, periodic z, run_pcg line for line, PcgCache3); gate 1 HELD: nz=1 bit-identical to the 2D solver (solution + iterations, lex + red-black, cached/uncached); extrusion z-invariant to the solve's accuracy (bit-identical planes for lexicographic decoupled); probes for the aggregation/colouring interaction ... Co-Authored-By: Claude Fable 5.1 <[email protected]>	2026-09-17 11:11:52 -05:00
Omar SobhandClaude Fable 5.1	7e135893a2	rtx-cfd/rtx-fsi PERF-2 P3-iii K-stream mode: each lane thread's device operator lives on its own CUDA stream (no rendezvous; set_plane_streams, RTX_FSI2O_PLANE_MODE=streams default | batch); stream-mode unit test digit-identical to the solo apply ... Co-Authored-By: Claude Fable 5.1 <[email protected]>	2026-09-17 06:40:43 -05:00
Omar SobhandClaude Fable 5.1	95ffde9591	rtx-cfd/rtx-fsi PERF-2 P3-iii: the MarchPlane — lane-table V-cycle kernels (ml_*), the batched apply over K lanes' own operators, the plane rendezvous inside the CG's preconditioner (lane thread-local, CG guard), set_plane_lane/plane_counters; the fsi2_overset_plane driver (K lane threads, one process); G-P0 unit tests: K distinct operators batched = solo apply bit for bit, uneven lanes served exactly ... Co-Authored-By: Claude Fable 5.1 <[email protected]>	2026-09-16 17:03:51 -05:00
Omar Sobh	de435eb91c	rtx-cfd: the legacy GPU modules back in the cuda build (repair in progress)	2026-09-16 07:15:24 -05:00
Omar SobhandClaude Fable 5.1	fc556f8a88	PERF-2 P3-ii: the device V-cycle as the CG's preconditioner — poisson/device.rs (one CUDA runtime per process, persistent per-operator buffers, the mg_vcycle.cu kernels at K = 1; upload r, run the V-cycle, download z; the f64 CG unchanged), MultigridParameters::device, Prepared holds the device hierarchy, the CG driver destructures the prepared operator instead of cloning it; EmbeddedPisoSolver::set_poisson_device, overset pass-through, harness knob RTX_FSI2O_MG_DEVICE=1; export_levels factored out; the quarantine's dangling cfg attribute fixed ... Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01YJPeT6WA2e7YvAnS875AHL	2026-09-16 01:16:55 -05:00
Omar Sobh	06a60b5fed	PERF-2 P3 bench: per-level comparison of the device V-cycle's work vectors against the CPU's (vcycle_f32_work) to locate the disagreement	2026-09-16 01:08:31 -05:00
Omar Sobh	cb1647c0ef	rtx-cfd: the legacy GPU solver modules (piso_gpu, simple_gpu, d2q9_gpu, d3q19_gpu, smagorinsky_gpu) kept out of the cuda build — broken since the initial commit; the PERF-2 benchmark uses cudarc directly	2026-09-16 01:05:39 -05:00
Omar SobhandClaude Fable 5.1	0dc95a8de5	PERF-2 P3: the batched device V-cycle microbenchmark — mg_vcycle.cu (masked variable-coefficient five-point red-black half-sweeps, residual, CSR restriction in a fixed order, prolongation, coarsest sweeps; [K][n] layout, blockIdx.y = march), LevelExport/export_hierarchy and vcycle_f32_reference on the CPU side, and the ignored cuda-feature test that checks the K = 1 device V-cycle against the CPU f32 reference and times K = 1 / 8 / 16 per march ... Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01YJPeT6WA2e7YvAnS875AHL	2026-09-16 01:03:02 -05:00
Omar SobhandClaude Fable 5.1	7f144e0005	PERF-2 P2: the red-black colour maps, the residual and the V-cycle's per-level maps on rayon threads (MultigridParameters::threads; RTX_THREADS in the harness; rtx_cfd::configure_threads) — each colour's values computed from the unchanged other colour into a scratch and written back, the L1 sum in the serial order: bit-identical to the serial red-black (pin: 4 right-hand sides at 4 threads); the coarsest level stays serial; no effect on the lexicographic regime ... Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01YJPeT6WA2e7YvAnS875AHL	2026-09-15 23:59:29 -05:00
Omar SobhandClaude Fable 5.1	cb5771fa71	PERF-2: red-black symmetric Gauss–Seidel smoother behind a knob (MgSmoother::RedBlack; default lexicographic = the recorded regime, bit-identical) — red/black cell lists per level, the symmetric pair red,black,black,red, the operator cache keyed on the smoother; EmbeddedParameters::poisson_smoother, harness knobs RTX_FSI2O_MG_RB (overset) and RTX_FSI2_MG_RB (embedded, the noise probe); pin: solves the masked problem to the same stop, agrees with lexicographic to 2e-12, cached = uncached bit for bit ... Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01YJPeT6WA2e7YvAnS875AHL	2026-09-15 23:48:55 -05:00
Omar SobhandClaude Fable 5.1	79c18def32	PERF-2 P1.1: the multigrid-PCG's prepared operator (hierarchy, f64 fine level, active cells, components) cached on the embedded solver and reused while the operator is bit-identical (an exact key over the coefficient bit patterns, the mask and the hierarchy parameters); solve_multigrid_pcg_cached gives the uncached solve's answer bit for bit (pin poisson_cache_exact.rs: five right-hand sides on one operator, a one-coefficient miss, both precisions); the CG driver split into Prepared::build + run_pcg ... Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01YJPeT6WA2e7YvAnS875AHL	2026-09-15 23:30:53 -05:00
Omar SobhandClaude Fable 5.1	172a26dee4	PERF-2 P0: intra-step profiler — StepTimers on the overset solver (RTX_PROFILE; overlap build / predictors / patch BiCGSTAB / background Poisson with its setup-vs-iterate split / round exchange / apply / end exchange), PoissonSolution carries setup_ns and iterate_ns, the harness times advance / restore / snapshot / load sampling / force / FEA predictor and prints the wall split of the coupled phase; no clock is read when profiling is off; the reclassified/step progress denominator fixed (was ×4) ... Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01YJPeT6WA2e7YvAnS875AHL	2026-09-15 22:25:52 -05:00
Omar SobhandClaude Fable 5.1	c3dbd5040a	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	2026-09-15 10:46:35 -05:00
Omar SobhandClaude Fable 5.1	415c32ab04	overset mesh: the flat-tip outline (P5-3 option B) — cylinder_flag_outline_deformed_tip / cylinder_flag_patch_deformed{,_from}_tip take the tip's corner radius (t = the recorded semicircle, bit for bit; smaller = the benchmark's flat face between corner arcs sampled at the wall spacing, point count fixed across the deformation, the tip's corners kept off the hull source); pins: corner t reproduces the recorded outline, the 2.5 mm outline has the exact area excess with no collapsed spacing, the O-grid builds straight and at ± 80 mm cold and warm at ny 41/62; harness knob RTX_FSI2O_TIP_CORNER (default 0.01) on the cold and warm builds, printed in both headers; pinned-toolchain fmt on touched crates ... Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01LzcjQX7tvgn87CQCyg9Cfr	2026-09-13 22:22:08 -05:00
Omar SobhandClaude Fable 5.1	0215c7d6a5	rtx-cfd: CurvilinearPisoSolver::momentum_balance — the patch's own momentum balance on its solved cells in the scheme's fluxes (outward ρFu_f with the predictor's face value, Laplacian-form μ∇u·S on the solved/acceptor interface and the wall, the least-squares pressure volume sum vs the face-pressure integrals); flux_force, wall_force, pressure_defect δP; overset_cfd1 prints it and the acceptor band's mismatch, saves the patch flux, and RTX_OVERSET_CFD1_LOAD=dir runs the diagnostics offline on saved fields ... Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-09-06 14:13:04 -07:00
Omar SobhandClaude Fable 5.1	6f9b0d43b2	rtx-cfd: OversetPisoSolver::momentum_residual — the background predictor's own staggered stencil (u_rhs/v_rhs, factored out of the predictor bit-identically) evaluated on every face of a NaN-masked field; solved faces read rounding, the active–fringe interface reads the composite's pressure level offset δ·h (cancels in the sum), prescribed fringe–fringe / fringe–hole faces read the stamping's momentum injection; hole ghosts (p, u, v) from a band widened three rows into the hole make every ring face evaluable; overset_cfd1 prints the buckets, the ring x-bands and δ at the settled state; pin: residual vanishes on the solved faces ... Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-09-06 13:25:14 -07:00
Omar SobhandClaude Fable 5.1	e2edff9b1d	rtx-cfd: overset A-P3 — the falsifier plate on the overset (FAILS the registered gates by one order less than the staircase); wall force; composite pressure-level pin; Schwarz stall detection ... patch_gen::{stadium, graded_fractions}: the falsifier plate as a stadium O-grid (semicircular ends r = half-thickness; 16 cells per end arc, straights graded 0.30 h -> h at 1.15, offset 6 h, 12 rows stretched 4x; 148x12 cells, every ray a normal, worst non-orthogonality 4 deg). CurvilinearPisoSolver::surface_force (+ PatchLoad): F = sum(-p_f S_f + mu (grad u + grad u^T)_f . S_f) on the wall faces with the wall cell's LSQ gradients (wall Dirichlet in the velocity fit); HELD on the phantom circle against the exact stress integral: 1.3e-2 / 6.3e-3 / 3.6e-3 at n = 32/64/128 (orders 1.05 / 0.81), 22x the staircase's accuracy. OversetPisoSolver: the composite p' level pinned to zero mean over the active cells every round (the coupled problem is pure Neumann; the temporal warm start handed each step's level to the next — background pressure 1e7 growing 5e4 per step on the falsifier; an unpinned level also inflated the relative Schwarz stop); stall detection (no progress over three rounds = the inner solvers' noise floor; 6560 of 150k steps burned the 20-round cap at n = 64, a 7.5 h n = 128 march); schwarz_stalled in the result. tests/overset_falsifier.rs (records; RTX_OVERSET_FALSIFIER_STRICT asserts the registered gates, _LADDER runs dt/2 and dt/4, _TRACE the top-12 spike steps): max spike 594 / 981 / 1720 N/m at dt / dt/2 / dt/4 (staircase 6490 / 12600 / 25600), rms spike 61-89 (810), far probe 502-1509 (7900), KE injection 0.16-0.21 J/m per event on the common cell set (2.6) — every large spike a ~104-cell full-row reclassification; exponent -0.77 (-1.0). The registered 5% gate (8.75 N/m) is missed 68x: the overset's own reclassification impulse is the finding (omni-cortex overset_metal_campaign.md §5.10); P3b = locate per cell, then the fringe flux balance. tests/patch_stadium.rs, curvilinear_loads.rs, overset_common::plate_patch. Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-09-05 04:32:43 -07:00
Omar SobhandClaude Fable 5.1	afd1bff6ee	rtx-cfd: overset A-P2 — the patch overlaps the background (OversetPisoSolver), gated S1–S5 ... Background = the embedded solver with a mask from the overlap classification (embedded/{mod,projection}.rs: module split, projection's solve/apply halves, set_overlap, fringe p' Dirichlet by elimination into extra_diag/rhs, anchor dropped, set_inner_stop_factor, phase API begin_step/solve_correction/ apply_correction/end_step; advance rebuilt on the phases — every suite digit- identical, FSI2 default line-for-line). Patch = the curvilinear solver with an acceptor ring (set_side_velocity; set_acceptor_ring/stamp_acceptors/ set_acceptor_correction; acceptor Dirichlet by elimination into PressureSystem.links so the BiCGSTAB stop stays in flux units — identity rows measured unconverged at 2431 iterations; same phase API). overset/overlap.rs: OverlapMap — hole/fringe/active from the patch's own indices (hole = body or k <= nn-1-overlap_rows, DEFAULT_OVERLAP_ROWS = 4 from the 2.9 h depth budget), dual-quad inverse-bilinear donors patch→fringe, lattice donors →acceptors, both invariants asserted, mass-defect measures. overset/mod.rs: OversetPisoSolver — advance (exchange rebuilt BEFORE the predictors from the previous corrected field), alternating Schwarz on the acceptor p' vector with Anderson(3) (plain Schwarz measured 0.82/round: floating patch, Neumann wall) and the previous step's vector as warm start (1 round/corrector at steady state), stop relative to the STEP's p' scale (the MG absolute stop is 1e-9/dt² in pressure — the whole second correction), set_patch_mesh, snapshot/restore carrying the warm-start vector. Gates: overlap linear-exact 1e-13, quadratic orders 1.96/1.99 (acceptors), 1.40/1.91 (fringe); half-couplings: patch with exact acceptors Stokes 2.07/1.98 + 2.08/1.98, upwind 0.84/0.84, background with exact fringe 7.86e-3/2.90e-3/ 1.09e-3 (1.44/1.41); two-mesh MMS n=32/64: background 8.717e-3/4.207e-3 (1.03x/ 0.97x the embedded circle), patch 1.322e-2/6.904e-3 (1.5-1.6x), orders 1.05/ 0.94, patch div <= 5e-13, overlap mass defect 3.6e-3 -> 8.2e-4 of the overlap flux (under the registered 1e-3 from n=64; disclosed at 32); motion: stationary patch through set_patch_mesh bit-identical, snapshot/restore with a pending mesh bit-identical, translating phantom circle 1.22x/1.19x the static level over 4.5 cells. Inherited, disclosed: poisson_equivalence's no-body multigrid pin fails by 3.9e-9 at d46fb0b (M1's commit; verified in a clean worktree). Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-09-04 19:24:13 -07:00
Omar SobhandClaude Fable 5.1	d46fb0b7a7	rtx-cfd: overset A-P1 GATED — the curvilinear patch moves and deforms under an exact 2-D DGCL ... StepGeometry (motion.rs): time-averaged face vectors S̄_f = ½(S^n + S^{n+1}) and swept volumes δV_f = S̄_f·δc_f — exact for linear node motion on any quad, so Σ sign δV_f = V^{n+1} − V^n is algebra (1.8e-14 measured; the EndOfStep control 2.1e-3). CurvilinearPisoSolver::set_mesh(next) names the end-of-step geometry; advance swaps it in, rebuilds operators + pressure matrix on it (L_f, LSQ gradients, no mesh-velocity term in the projection), keeps the old mesh for V^n and the explicit boundary data; predictor in the conservative ALE form V^{n+1} û = V^n u^n + dt(−Σ sign (F − δV/dt) u_f + ν D + f V^n), written as u·(V^n/V^{n+1}) + … so a stationary mesh is bitwise the static path; fluxes on S̄_f; snapshot carries both meshes; swept_face_rule knob (Trapezoidal default, EndOfStep = negative control). Stokes limit keeps the mesh flux (was dropped with convection) and centres it (upwinding it cost an order: 1.06/1.00). Gates (tests/curvilinear_ale.rs, 11 tests, 83 s): uniform flow on a wiggling AND bending annulus 4.44e-15 over 400 steps, p exactly 0, 0 pressure iterations; control deviates 4.9e-5; stationary mesh through the moving path bit-identical (both diffusion variants); snapshot/restore on the moving mesh bit-identical; Taylor–Green orders unchanged — upwind 0.995/0.976 vs fixed 0.987/0.975 at 1.05× error, Stokes 1.92/1.97 vs 1.94/1.99 at 2.4×, moving annulus 2.11/2.02; linear-field falsifier 1.95/1.92 (annulus), 1.91/1.43 (square, sliding wall nodes). P0 ladders re-run identical to every digit. Rule from the diagnosis: start a moving run ON the t = 0 mesh and sweep less than a cell per step — a first step that jumped 2–4 cells imprinted an O(displacement) error no refinement removed (dt- and motion-independent). Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-09-04 17:00:04 -07:00
Omar SobhandClaude Fable 5.1	c63d79c300	rtx-cfd/rtx-fsi: overset A-P0 GATED + M1 precision probe — curvilinear collocated PISO: relative-reduction pressure stop (the absolute stop floored |du/dt| at 2e-4 on 64²), line-implicit-n sign fix, adjustPhi; gates: Cartesian reduction 1.37–1.40x the staggered error at orders 0.83/0.90; skewed stretched periodic annulus Stokes orders 2.30/2.06 (explicit and line-implicit), upwind 1.08/0.80; Poiseuille exact to 1e-9 on Cartesian and affine-sheared periodic channels (both diffusion variants), varying-skew channel order 2.02 (v 1.9), cell mass 1e-14; divergence ≤ 1e-11 relative every step; snapshot/restore bit-identical. M1: poisson.rs multigrid hierarchy generic over MgScalar (f32/f64), f64 CG keeps its own fine level; MgPrecision on MultigridParameters/EmbeddedParameters/PisoParameters, set_poisson_precision, harness RTX_FSI2_POISSON_F32 (march + noise probe, printed marker); f64 arm bit-identical in vivo (FSI2 default line-for-line with 08-31), f32 arm holds the noise floor and stall pins and the FSI2 band; poisson_equivalence f32 arm ... Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-09-04 12:40:43 -07:00
Omar SobhandClaude Fable 5.1	52da75a3a9	rtx-cfd: curvilinear collocated PISO on a structured patch (overset A-P0, WIP) — PatchMesh (right-handed s,n; periodic seam with shift; face metrics), patch generators (TFI, skewed annulus, sheared/varying-skew channels), CSR + Jacobi-BiCGSTAB, the Zang–Street–Koseff incremental step with the node-based 9-point L_f, LSQ gradients, explicit and line-implicit-n predictors, adjustPhi; tests: mesh metrics (5 green), operators exact on linear fields incl. the seam (green), sparse (2 green), MMS ladder (Cartesian 16/32: 1.37–1.39x the staggered error, order 0.83; n=64 stalls at a |du/dt| floor 2e-4 — open, tolerance-scaling hypothesis), annulus/Poiseuille not yet run ... Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-09-04 05:00:08 -07:00
Omar SobhandClaude Fable 5	6c48e53998	rtx-cfd: indexed polygon SDF — bit-identical queries, the fluid's measured hot function cut ... The 2026-08-30 fluid profile (symbolized samples, rigid AND coupled phases of the FSI3 default) attributed the fluid step to the function: polygon_signed_distance 51% rigid / 35% coupled — the embedded mask rebuild and its ghost reconstruction walk every edge of the ~150-vertex interface polygon for every cell-centre and face query, every step. (Also measured, refuting the parked consolidation: Level::new — the MG hierarchy build — is 0.5-0.7% in BOTH phases; caching it would buy nothing. The MG smoother at 34-40% is the honest remaining fluid cost.) PolygonSdf (solvers/incompressible/polygon_sdf.rs): a binned edge index whose query is BIT-IDENTICAL to polygon_signed_distance by construction — per-edge distances use the same float ops, the ring search provably visits a superset of the argmin (convex-projection lower bound sqrt(d_out^2 + ((r-1)b)^2)), and parity XORs the same ray tests over exactly the straddling edges (y-binned). Equality is ASSERTED, not assumed: tests compare to_bits against the brute force over ~40k adversarial points (flag-like walks, random polygons with degenerate zero-length edges, horizontal-edge/vertex-y rays). Wired into EmbeddedBody::polygon and the FSI harness's shared geometry (rebuilt per set_geometry, ~microseconds for 150 edges). Verification — the bar for a bit-exact change is digit identity, and it holds: FSI2 and FSI3 committed defaults reproduce EVERY printed digit of the banded-LU baseline logs (uy 3.7732±3.7920 / 6.0229± 25.2190 mm, conservation 8.26e-12 / 1.49e-12, rigid drags 121.4 / 426.9); rtx-cfd full suite 0 failures; rtx-fsi lib/piston/transfer/ FSI1 green. The study pins need no re-run: the trajectories are unchanged by construction and confirmed by measurement. Wall clock: FSI2 rigid 323 -> 167 s (1.93x), whole default 400 -> 225 s; FSI3 rigid 420 -> 250 s (1.68x), whole default 539 -> 343 s. Cumulative with the banded LU this session: FSI3 default 944 -> 343 s (2.75x), FSI2 524 -> 225 s (2.33x). Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-08-30 07:47:42 -05:00
Omar SobhandClaude Fable 5	4534d90684	rtx-fea + rtx-cfd: the single-step seams FSI2 stands on ... rtx-fea: NonlinearDynamicAnalysis refactored onto a NonlinearDynamicStepper - set_nodal_forces on both (the interface load of a coupling subiteration, replaceable between steps and between subiterations of one step); - step(&DynamicState) is a pure function of the start-of-step state and the current forces - commits nothing, so a partitioned coupling re-runs one Newmark step to the interface fixed point (the piston semantics); - run() marches through the same stepper: one code path, pinned from both ends (linear limit, CSM3, and a new manual-drive == run() assertion); - new test: a nodal step load oscillates about the *static* nonlinear analysis's deflection (cross-code-path, mean within 3%, amplitude 6%), with re-run determinism and force-swap sensitivity asserted mid-march (a one-step response to a force change is ~ beta dt^2 - the first assertion draft demanded 10% and was corrected against the physics). rtx-cfd: the subiteration seam and the moving no-slip closure - EmbeddedPisoSolver::snapshot()/restore() (mask + time + init flag; the mask is now Clone): re-running a fluid step within a subiteration is bit-identical to never having diverted - proven on a moving body with cells flipping in the re-run window; - polygon_interface_velocity: nearest-edge linear interpolation of per-vertex velocities, exact for the linear-along-edge boundary data a finite-element interface hands over - the no-slip closure that replaces FSI1's zero-velocity polygon. Suites: rtx-fea 567, rtx-cfd 325, rtx-fsi piston+transfer - all green. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-20 20:00:49 -07:00
Omar SobhandClaude Fable 5	c0f5a86f03	rtx-cfd: the embedded-body pieces FSI1 stands on (belongs with b82f307) ... EmbeddedMask::traction_at (the per-sample traction factored out of surface_force, so a coupling loop can load a structure at its own quadrature points), EmbeddedBody::polygon and the public polygon_signed_distance (a deformable interface as a vertex list, usable behind a lock through EmbeddedBody::from_sdf). Left unstaged by mistake in b82f307 — that commit's FSI1 test needs these to compile. Co-Authored-By: Claude Fable 5 <[email protected]>	2026-08-20 17:22:44 -07:00
Omar SobhandClaude Fable 5	327da7ff47	rtx-cfd: multigrid-PCG projection — 30x faster, same answers — and the CFD1 refinement study ... Falsifier 4 of the Turek–Hron geometry decision fired (the SOR projection cost 0.09 s/step at 250x41 and an hour per run at 5 mm); this answers it. solvers::incompressible::poisson: PoissonProblem (cell-centred five-point SPD operator as per-cell face coefficients + Dirichlet diagonal extra + active mask) and solve_multigrid_pcg — conjugate gradient preconditioned by one V-cycle of geometric multigrid: aggregation by 2 per direction (odd sizes absorbed, coarse cell active iff any child is), the Galerkin coarse operator for piecewise-constant prolongation / summation restriction, symmetric Gauss–Seidel smoothing, coarse correction scaled by 2 (Braess's under-correction of unsmoothed aggregation; scalar, so the preconditioner stays symmetric and positive on range(A)), L1 TRUE-residual stop with a stagnation guard. Singular systems are handled per connected component of the active cells (mean projection and level per pure-Neumann component; the anchor's component to p[anchor] = 0). PoissonSolverKind::{Sor, Multigrid} on PisoParameters / EmbeddedParameters; Sor is the default and its code is byte-for-byte untouched; an unconverged multigrid solve falls back to the SOR sweeps for that projection. Verified (poisson/tests.rs, tests/poisson_equivalence.rs): - PCG iterations to cut the residual 1e-8 on the closed Neumann box at 32^2..256^2: 4, 4, 4, 4; ragged masked domains 8/8/8; - manufactured recoveries to ~1e-14; Galerkin identity A_c v = R A P v to 7e-15 on every level (masked, outlet column, non-uniform conductances); V-cycle symmetric to 1e-14; NaN-poisoned inactive cells untouched; - two Neumann components with opposite imbalances, and a Dirichlet component beside an imbalanced Neumann one (review scenarios): converge, each component right up to its own constant; - speed vs plain SOR at the same stop: 22.7x (128^2), 41x (256^2); - same answers as SOR: PISO MMS 4.6e-8 relative, Taylor–Green divergence 1.4e-9 every step, embedded-circle MMS 7e-8, no-body bit-identity with MG on both solvers, channel+outlet+circle 1.4e-10; CFD1 loads identical to four digits at 0.003 s/step vs 0.094 (30x). CFD1 refinement study (tests/turek_hron_cfd.rs, three grids, 257 s): h = 10 / 6.6 / 5 mm -> control-volume drag 15.6156 / 15.2829 / 15.0988 vs 14.2929 (+9.25 / +6.93 / +5.64%), apparent order 0.71, Richardson extrapolate 14.04; surface route and lift not monotone (flag 2/3/4 cells thick) — the test asserts the measured band at the finest grid. Built with a 4-agent workflow (core, integration, refinement study, adversarial review); the review found no defects and four risks, three fixed here (per-component projection, one symmetric smoother-sweep parameter, acting on `converged` with an SOR fallback) and one recorded (isotropic aggregation loses grid-independence on anisotropic cells). rtx-cfd 301 -> 318 green. Co-Authored-By: Claude Fable 5 <[email protected]>	2026-08-20 10:20:25 -07:00
Omar SobhandClaude Fable 5	c25f15b3c4	rtx-cfd + rtx-fea: embedded-boundary PISO and total-Lagrangian SVK — the first two Turek–Hron rungs ... The Turek–Hron geometry decision (omni-cortex docs/turek_hron_geometry_decision.md) chose an embedded boundary on the fixed Cartesian MAC grid over body-fitted unstructured ALE; this commit builds the first rung on each side of the ladder, verified MMS-first. rtx-cfd — solvers::incompressible::{embedded, embedded_body}: EmbeddedPisoSolver is the fixed-grid PISO predictor/projection with per-side domain boundaries (ALE's SideBoundary semantics, so the channel has an outlet), a (x, y, t) boundary-velocity function, and an optional EmbeddedBody (signed distance + surface velocity; circle / rectangle / union). EmbeddedMask classifies cells (fluid iff phi > 0 at the centre) and faces (fluid iff both cells fluid; ghost within 1.5 h; solid deeper); the predictor updates fluid faces only, the projection enforces continuity on fluid cells with zero coefficient across prescribed faces, ghost faces are re-imposed after each projection from a boundary-intercept least-squares linear fit (exact for linear fields), the net ghost mass flux is removed uniformly so a Neumann projection stays compatible, and loads come by two routes: surface-stress reconstruction (full viscous traction) and a control-volume momentum balance. Verified (tests/embedded_mms.rs, tests/turek_hron_cfd.rs): - no body, closed box: bit-identical to PisoSolver over 200 steps; - embedded off-centre circle MMS 16/32/64: velocity orders 0.92, 0.97 (plain PISO 0.85, 0.91), pressure 0.96, 0.90, max |div u| <= 9e-8 on every fluid cell, compatibility correction 6e-4 -> 3e-5; force on the circle vs the exact surface integral: surface route 0.52 -> 0.29 -> 0.15, control-volume route 0.61 -> 0.30 -> 0.15 (both first order, two unrelated readings of the same solution); - Turek–Hron CFD1 (Re 20, h = 10 mm, flag two cells thick), settled to four digits: surface drag 15.71 / lift 0.94, control-volume drag 15.62 / lift 1.08 vs reference 14.29 / 1.119 — the drag routes agree to 0.6%, both +9.5%. A coarse first number; the refinement study waits on a multigrid projection (SOR: 0.1 s/step at 250x41 in the test profile). Fourteenth defect of the campaign: the fixed-grid PISO predictor zeroes the transverse convective face velocity on its domain sides (exact for walls); carried into a solver with an outlet it dropped the OUTGOING momentum flux through the outlet side of the v control volumes, the last column accumulated, and CFD1 went NaN at t ~ 4 s. Found by printing where max |u| lived (x = 2.5) after halving dt changed nothing. Fluxes now come from the stored boundary faces on every side. rtx-fea — elements::total_lagrangian + NonlinearStaticAnalysis:: with_total_lagrangian(): Green–Lagrange strain, second Piola–Kirchhoff stress from a St. Venant–Kirchhoff law on the material's Lamé parameters (plane strain in 2-D), B_L of the current deformation, material plus geometric tangent; dead-load body force per reference volume. Verified (tests/total_lagrangian_svk.rs): - zero displacement: the plane-strain stiffness to 1e-13; - tangent = d f_int/du by central differences at 20% random displacement (Quad4, Quad8, Hex8): relative < 1e-7, symmetric to 1e-12; - a 34-degree rigid rotation produces no internal force; the small-strain routine does (negative control); - manufactured finite-strain solution, body force by FD of the exact P = F S: Quad4 orders 1.95, 1.98; Quad8 2.93, 3.03, 3.02 (an 8% amplitude, Green–Lagrange strain to -0.25 near SVK's compressive limit E = -1/3, broke Newton on fine meshes — the material, not the code; 3% is clean); - Turek–Hron CSM1 at 70x4 Quad8: u(A) = (-7.060, -65.43) mm vs (-7.188, -66.10), 1.0% / 1.8%, converging from below (35x2: -65.14); CSM2: (-0.4604, -16.79) vs (-0.4690, -16.97), 1.1% / 1.8%. rtx-cfd 293 -> 301 green (5 unit + 3 integration), rtx-fea 559 -> 564. Co-Authored-By: Claude Fable 5 <[email protected]>	2026-08-20 08:51:32 -07:00
Omar SobhandClaude Fable 5	4bd98b5264	rtx-cfd + rtx-fsi: the added-mass piston — partitioned FSI on the real ALE fluid ... The first coupled fluid-structure computation in the workspace, verified against a closed form, and the first time rtx-fsi's added-mass claims run against a real discretised fluid rather than a linear model map. ALE extensions: per-side boundaries (Velocity / SlipWall / PressureOutlet) and moving boundary lines. A moving Velocity side is a material wall whose prescribed normal velocity must equal the line's own motion; a pressure outlet takes Dirichlet p' = 0 in the projection (replacing the Neumann anchor) with a zero-gradient predictor on its faces. Fluid half verified alone (tests/ale_piston_channel.rs): prescribed piston motion, slip walls, outlet. The incompressible rigid column is exact DISCRETELY - continuity forces every u to the wall's discrete velocity (8e-12) and the projected pressure is exactly linear with gradient rho times the wall's backward-difference acceleration (2.5e-9). Coupled benchmark (rtx-fsi/tests/piston_added_mass.rs): elastic piston (Newmark average acceleration) against added mass rho*L*H at mass ratio 6.25, rtx-fsi's Subiterated driving a real fluid/structure pass per step: - plain staggered diverges in 7 subiterations (Causin-Gerbeau-Nobile on a real solver); - Aitken converges at 3.0 subiterations/step onto T = 1.07009 vs the closed form 1.06999 - 9.8e-5 relative, halving with dt; - outlet flux matches the piston sweep to ~1e-9 every step. Discrete-analysis finding: Newmark beta scales the staggered added-mass threshold - the iteration gain is beta*m_a/(M + K*beta*dt^2), so the continuous ratio 2.5 CONVERGES at beta = 1/4 (gain 0.625, measured ~17 passes/step) and the benchmark needs ratio 6.25 (gain 1.56). Two real defects found and fixed, twelfth and thirteenth of the campaign: 1. rtx-cfd ale::advance re-stamped boundary faces at t_old from the current boundary function, which in a coupling loop carries the NEW interval's wall velocity - the predictor's old state had interior u = w0 but wall face u = w1, leaving an O(dt) pressure artifact confined to the wall-adjacent cells (p exact to 6e-11 everywhere except the wall cell at 4.7e-5). The start-of-step boundary faces are whatever the previous step's end-of-step application left there. 2. rtx-fsi aitken_factor guarded its denominator - a SQUARED residual- difference norm - against a bare f64::EPSILON, silently disabling Aitken below residual ~1e-8 and degrading to unit relaxation exactly in the well-converged regime; the repulsive fixed point then amplified 1e-9 residuals back up and the coupling diverged. Third instance of the absolute-threshold species (NNLS, ECSW). The guard is relative now; aitken_is_scale_invariant pins it at initial residual 1e-9. rtx-cfd 293 green (+1), rtx-fsi 29 green (+3). rtx-fsi's lib gains only the relative guard; the coupling layer still depends on no solver (rtx-cfd is a dev-dependency of its tests). Co-Authored-By: Claude Fable 5 <[email protected]>	2026-08-20 06:10:13 -07:00
Omar SobhandClaude Fable 5	259c5baa63	rtx-cfd: ALE on a moving tensor-product grid, DGCL-exact by construction ... The first brick of the Turek-Hron frontier: PISO (explicit conservative predictor + SOR projection) generalised to a staggered grid whose x- and y-lines move arbitrarily each step while the domain boundary stays fixed. The discretisation choice that carries everything: time-averaged face areas (A^n + A^{n+1})/2 in both the fluid fluxes and the face-swept volumes. For tensor-product motion the discrete geometric conservation law then holds as an algebraic identity, so uniform flow is a machine-precision fixed point, not a truncation-order one: - DGCL test: uniform (0.7, -0.4) on a 16x12 grid with interior lines wiggling out of phase, 400 steps: max deviation 7.9e-15 (~35 ulp). Negative control with end-of-step areas (per-step cell error exactly dw*dh/V, the cross term the identity absorbs): 1.5e-2 - a 1e12 separation, so the test can fail. - Degeneracy: zero motion on a uniform grid vs fixed-grid PISO over Taylor-Green steps: max difference 2.2e-16 - one ulp - pinning every geometric generalisation to the verified implementation. - Physics under motion: Taylor-Green on the wiggling mesh, L2 error 2.42e-2 -> 1.07e-2 (n=16 -> 32, order 1.17); moving-mesh error at n=32 sits below the fixed-mesh 1.1532e-2 (PISO's published value to four digits); energy decay unchanged by the motion. One trap documented in the test: the projection's inner-stop floor (0.1 * tolerance * reference_flux) at an engineering tolerance lets a one-sweep partial p' accumulate into p, whose gradient perturbs the velocities at ~1e-11 with the geometry blameless. The DGCL run must use a rounding-level tolerance because machine-precision preservation is the claim under test. Measured: 3.6e-11 at tol 1e-9, 7.9e-15 at 1e-13. Incompressibility needs no mesh-velocity term: subtracting the GCL from moving-cell mass conservation leaves plain div(u) = 0 on the current geometry, so the projection is the fixed-grid one with non-uniform coefficients. 292 rtx-cfd tests green (288 + 4). Co-Authored-By: Claude Fable 5 <[email protected]>	2026-08-20 05:31:12 -07:00
Omar SobhandClaude Fable 5	796cf173e6	rtx-cfd: second-order convection by deferred-correction TVD; MMS order 1.84, cavity closes on Ghia ... First-order upwind's O(h) numerical viscosity was the measured limit on the whole discretisation: MMS order ~0.9 at Re = 20 against 2.05 in the Stokes limit. This adds a ConvectionScheme parameter to SimPLE — Upwind (default, behaviour unchanged), TvdVanAlbada, TvdVanLeer — implemented by deferred correction: the upwind operator stays implicit, so a_p = sum(a_nb) and diagonal dominance survive unconditionally, and the limited high-order-minus-upwind flux difference enters the source explicitly at the current iterate. At a fixed point the two agree, so the converged answer is the TVD discretisation. Faces whose far-upwind node lies outside the domain fall back to pure upwind; wall faces pass no mass, so no correction enters. Measured by the manufactured solution (van Albada, 16 -> 32 -> 64): L2 velocity 1.325e-3 4.406e-4 1.232e-4 orders 1.59, 1.84 (upwind) 3.516e-2 1.954e-2 1.038e-2 orders 0.85, 0.91 The error is 27x to 84x below upwind's at equal resolution, the order climbs toward 2 (the shortfall is limiter clipping plus the boundary fallback, both of which shrink with h), the pressure error falls at the same rate, and continuity still holds to solver tolerance in every cell. On the Re = 100 lid-driven cavity at 65^2 the centreline minimum moves from -0.1932 (upwind) to -0.2036 against Ghia's -0.2109 — 59% of the remaining gap closed at equal resolution, converged in 790 iterations — and the vortex position moves from 0.5000 to 0.4844 toward Ghia's 0.4531. Both new cavity bounds exclude the upwind values, so falling back to first order fails them. 284 tests, 0 failing. Co-Authored-By: Claude Fable 5 <[email protected]>	2026-08-19 19:16:48 -07:00
redclawsystems	4d88dc0584	Initial commit	2026-03-04 00:08:42 +00:00