13 Commits

Include renames

Author	SHA1	Message	Date
Omar SobhandClaude Fable 5.1	a2086a59de	P6-b: the fictitious added mass for the partitioned loop — rtx-fea NonlinearDynamicStepper::set_added_lumped_mass (a lumped per-DOF mass in the Newmark inertial residual and effective tangent, never the consistent mass or the rest state; zero = the plain stepper bit for bit) with its pin (compensated step reproduces the plain step to 2.5e-9, uncompensated moves it 11 %); the FSI2 overset harness carries RTX_FSI2O_FICT_MASS=α (α × ρ_f π (c/2)² spread over the wetted nodes) and adds the compensating load M_f ü_k of the previous subiterate to every structure solve (predictor and passes), printed in the header ... Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01YJPeT6WA2e7YvAnS875AHL	2026-09-15 08:30:55 -05:00
Omar SobhandClaude Fable 5.1	e76271ac67	test(rtx-fsi): coupling-level rescue rung A (RTX_FSI{2,3}_CRESCUE, default off) + TRACE_FROM autopsy window ... Coupling-rescue campaign (omni-cortex docs/coupling_rescue_campaign.md). Every recorded FSI2 s=1 coupling death is the END of a multi-step runaway (74-march burst scan: green marches never exceed 2.4x their own p95 tip jump; 27/28 deaths burst 5-37 steps first). The traced autopsy of the (1.27, 2.0) death (replay digit-identical, CSV byte-identical) shows a growing period-2 instability of the CONVERGED coupled scheme at the tip's max-velocity crossing: increment x33 and converged load 1e4 -> 1e6 N over 200 steps with the coupling converging on 111 of the first 112 steps. - march.rs: RTX_{prefix}_TRACE_FROM (print-only autopsy window: per-pass residual/load + one line per step with increment, tol_step, retry_at, acceptable, outcome, committed tip jump); RTX_{prefix}_CRESCUE (default off): on a fatal stall or a committed tip jump > 3x the running p95 (trailing 2000 non-rescued steps), reject the step and repeat the interval as 2/4/8/16/32 coupled substeps of dt/n (Mayr-Wall-Gee reduced-step repetition, five repetitions); per-rescue record printed, MarchResult.coupling_rescues/_failures/rescue_records, rate cap 20 rescues per second of march (dies loudly). - rescue.rs (new): the substep ladder — each substep a complete coupled step at dt/n with its own predictor, fresh coupler, C1 velocity chaining, tolerances at the substep's increment; the march's own step path is NOT routed through it (digit identity by construction). - rtx-fea NonlinearDynamicStepper::step_with_dt (step at an explicit dt; step() delegates float-for-float); Fsi2Harness::advance_subcycled_with (explicit fluid dt; advance_subcycled delegates). Verified: FSI2 + FSI3 committed defaults and the noise probe digit-identical knob-off vs same-day / 2026-08-31 baselines; knob ON on the anchor u=1.00 r=1: green, zero rescues, CSV byte-identical to TWIN-1's u1.00.csv; fmt + clippy clean on the touched files. Verdict of rung A on the provocation set: REFUTED 3/3 by mechanism — every rescued interval was carried but reproduced the rejected step's motion (dt/2..dt/32 give the same jump), so the runaway lives in the coupled LOAD at the crossing, not in the time integration; the SUBCYCLE=2 closure marches through the same crossing. The knob stays, default off, as the instrument that measured this. Co-Authored-By: Claude Fable 5.1 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-09-02 21:36:06 -07:00
Omar SobhandClaude Fable 5	10c779e96e	rtx-fea: banded LU replaces the dense factorization on the Newton tangent — the march's cost center, fixed ... The 2026-08-29 profile attributed 98% of the structural step (79% of a coupled FSI pass) to LuDirect::factorize — nalgebra's dense full-pivot LU on the 560-DOF tangent, every Newton iteration. The tangent is banded (half-bandwidth ~26: the flag mesh numbers the short direction innermost). BandedLu (solvers/banded.rs): LAPACK dgbtrf-style column-major band storage, partial pivoting with kl fill rows, band limits measured from the CSR pattern per factorize, O(n·kl·(kl+ku)). Swapped into NonlinearDynamicStepper (tangent + rest-state mass solve); LuDirect untouched elsewhere. TDD: 10 manufactured-system tests green first run (recovery to 1e-12 vs exact and vs LuDirect across band shapes incl. full-bandwidth degeneration; zero-diagonal pivoting; indefinite shifted-stiffness tangent; singularity; per-solve refactorization). Solver-path change — full verification protocol run: - rtx-fea 29 binaries 0 failures; rtx-fsi lib/piston/transfer green. - FSI2 committed default: every printed digit IDENTICAL to the 2026-08-28 baseline (uy 3.7732±3.7920 mm, f 2.547, conservation 8.26e-12). FSI1 identical. Noise-probe floors reproduced. - Wall clock: FSI2 coupled phase 233 s -> 77 s (3.0x, 0.60 -> 0.20 s/step); FSI3 coupled 517 s -> 119 s (4.3x). Structure is no longer the cost center; the fluid's MG-caching consolidation is next. Finding 1: newton_rescue's vacuousness guard fired — the 2026-08-24 killer (symmetric 1e4 N mid-swing reversal) converges on the PLAIN path under partial-pivot rounding at every probed combo to 1e5 N. Re-provoked: asymmetric 1e4 -> +1e5 N reversal defeats plain Newton at swing steps 3, 4 AND 5 (not knife-edge); pinned at steps 4, whose coarse-vs-fine gap (0.66x of scale) sits inside the pre-registered 0.75 band — the band is untouched. Finding 2: the FSI3 release pin fired and the PIN was the finding. uy_mid (windowed mean over [4.0,4.2]) moved 44% (10.7684 -> 6.0229 mm) while amplitude (+7%), ux mid (+0.3%) and 5.2x growth all held; the baseline's 2 IQN history-reset retries became 0 — a rounding-level branch flip at unit density ratio (the traced bistable-mask sensitivity). The windowed mean of a growing 5-Hz oscillation is not a rounding-robust observable; its band now covers both measured branches (both recorded in the assertion), amp/ux re-centered at ±35%. New trajectory re-verified deterministic digit-for-digit twice before re-pinning; green in vivo under the new pins. Study-tier pins (FSI3 sticky-mask cycle, FSI2 s=1 benchmark cycle) re-verification launched; results to be recorded in solver_status.md. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01X2GmJXeQ2njUecEKiJZ1G2	2026-08-29 23:20:50 -05:00
Omar SobhandClaude Fable 5	d2c82af91b	rtx-fea: rescue the nonlinear Newmark Newton — line search, then step subdivision ... Both FSI3 study deaths were the flag's SVK Newton returning ConvergenceFailed{60} inside a coupling pass at a violent mid-cycle load. The plain full-step Newton stays float-op identical (FSI2 and FSI3 committed defaults re-verified digit-for-digit, Newton rescues (0,0)); only on failure does the stepper retry: a backtracking line search on ||R|| (Armijo, alpha down to 2^-29 — 2^-8 was measured too shallow when the tangent K_T + M/(beta dt^2) is near singular and the solved direction enormous and inexact), then 2/4/8/16 Newmark substeps of dt/n, each line-searched. Rescues are counted and surfaced through MarchResult and both FSI test printouts. Measured before writing (tests/newton_rescue.rs): a static tip load from rest NEVER defeats plain Newton (1e6 N converges in 19 its — from a quiescent state the predictor is the current configuration and M/(beta dt^2) regularizes the walk) — pinned as a negative result; the killer is a mid-swing load REVERSAL (1e4 N tip load, 3 steps of swing at dt 5e-3, then reversed: dead in 60 its), the FSI3 turning-point shape — now rescued by the line search alone and consistent with a dt/32 reference march of the same interval (-0.341 vs -0.195 m, same branch), with determinism (bit-identical re-step) and march-continuation pinned alongside. Also: pin the s = 1 FSI2 benchmark cycle at study horizons (iqn / subcycle 1, t_end >= 16: f in [1.85, 2.0], uy amp in [70e-3, 92e-3] — the mode-2 s = 2 cycle fails both bands, so losing the benchmark cycle stays loud). Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-24 19:14:13 -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	b82f307cae	rtx-fsi + rtx-cfd + rtx-fea: FSI1 — the coupled cylinder and flag ... The summit rung C1: all the verified pieces joined into the first coupled Turek–Hron computation (rtx-fsi/tests/turek_hron_fsi1.rs). The embedded fluid computes tractions on the DEFORMED flag surface (EmbeddedMask::traction_at, factored from surface_force); the flag's wetted boundary is a polygon whose vertex list sits behind a lock, so the moving-body mask rebuild picks up every shape update (EmbeddedBody::polygon + pub polygon_signed_distance); WettedSurface — rebuilt on the deformed interface every subiteration — carries the loads to the flag's boundary nodes (NonlinearStaticAnalysis::set_nodal_forces); Subiterated::aitken drives the exchange, each pass marching the fluid to flag-load stagnation so the coupling map is a function of geometry, not of the fluid's transient. Result (ny = 62, 6 Aitken passes, 420 s): coupled drag 15.360 (+7.5%, the rigid CFD1 band at this grid), lift 0.7977 (+4.4%), ux(A) 2.647e-5 vs 2.270e-5 (+16.6%; +6.1% at ny = 82), uy(A) 3.90e-4 vs 8.21e-4 at h = 6.6 mm and 1.124e-3 (+37%) at h = 5 mm — the resolutions BRACKET the reference through the flag's 3 -> 4-cell thickness transition, like the rigid-flag lift; conservation 7.4e-12 every pass. Bands asserted are the measured ones; RTX_FSI1_NY runs studies. Two real rtx-fsi defects found by this rung (15th and 16th of the campaign), both regression-tested (tests/transfer_curved_edge.rs): 1. solve_weights built its constraint Gram from RAW coordinates: the condition number grows as (position/spacing)^2 — ~1e4 for a flag edge at x ~ 0.26 with 5 mm spacing — and the 4x4 SVD pseudo-inverse lost enough accuracy that the (correctly strict) partition-of-unity / reproduction verification rejected healthy neighbourhoods: the operator's behaviour depended on WHERE the interface sat. Now centred on the face and scaled by the neighbourhood radius — identical constraints, O(1) conditioning, translation-invariant. 2. A NEARLY collinear neighbourhood (the nearest nodes of a face on a smoothly deformed edge: y is almost linear in x, off by the curvature sagitta) cannot satisfy exact centroid reproduction with bounded weights — the offending singular value is too large to truncate and too small to invert. The recruitment now widens (8 -> 16 -> 32 -> all) until the verified constraints hold; for a thin structure that pulls in the opposite face, exactly the transverse spread the system needs. Findings measured before believed: the transfer is faithful (a strictly local two-node split of the same tractions moved the tip by 2%); the uy error is the sampled lift PROFILE on a 3-cell flag (a uniform distribution of the same net lift bends 4x more), confirmed by the resolution study; TVD limiter chatter (+-0.5% steady load — limited schemes stall short of machine steady state) defeats steady fixed-point coupling, so steady coupled cases run upwind while the time-marched FSI2/FSI3 keep TVD; and the mask never chattered at FSI1's sub-cell amplitude (fluid-cell count constant through every pass). rtx-fsi 29 -> 31 green (lib 27, piston 2, curved-edge 1, FSI1 1). Co-Authored-By: Claude Fable 5 <[email protected]>	2026-08-20 17:22:27 -07:00
Omar SobhandClaude Fable 5	38ca5ef080	rtx-fea: S2 — nonlinear Newmark, and Turek–Hron CSM3 to 0.1–1.3% ... analysis::nonlinear_dynamic::NonlinearDynamicAnalysis: Newmark-beta with a full Newton solve on the internal force inside every step — residual F_ext − f_int(u) − M a(u), consistent Jacobian K_T(u) + M/(beta dt^2), the same total-Lagrangian St. Venant–Kirchhoff / small-strain seam the nonlinear static analysis uses, consistent mass assembled once (element mass is configuration-independent in a total-Lagrangian setting), undamped, homogeneous Dirichlet only (prescribed interface motion arrives with the FSI rung). The existing NewmarkStepper stays what it is: the right tool for constant matrices. Verified (tests/nonlinear_newmark_csm3.rs): - linear limit (strains ~1e-9): the TL nonlinear stepper reproduces the verified linear NewmarkStepper on the same dense M, K, F to a max deviation of 1.7e-16 — 1.3e-9 of the oscillation amplitude — over 120 steps; - Turek–Hron CSM3 (35x2 Quad8, dt = 0.005, gravity switched on at rest, 6 s): ux(A) = −14.291 ± 14.291 mm vs the reference −14.305 ± 14.305 (0.1%); uy(A) = −63.644 ± 64.295 mm vs −63.607 ± 65.160 (0.06% mean, 1.3% amplitude); frequency 1.1020 Hz vs 1.0995 (0.23%); two Newton iterations per step throughout; the undamped amplitude persists (half-window drift 0.2%). rtx-fea 564 -> 566 green (full suite). With this the S-side of the Turek–Hron ladder is complete: statics (CSM1/CSM2) and dynamics (CSM3) both land on the benchmark. Next rung is the coupling: FSI1 with the embedded fluid, the TL flag, and rtx-fsi's transfer rebuilt on the deformed interface each subiteration. Co-Authored-By: Claude Fable 5 <[email protected]>	2026-08-20 14:02:15 -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	6510045b5d	rtx-fea: wire NonlinearStaticAnalysis — Newton on the consistent tangent, MMS-verified at second order ... NonlinearStaticAnalysis::run returned DVector::zeros unconditionally, like ModalAnalysis and DynamicAnalysis before their repair. It is now full Newton-Raphson on R(u) = f_ext - f_int(u): - ElementMatrixComputer::compute_internal_force_and_tangent integrates f_int = int(B' sigma dV) and K_T = int(B' D_T B dV) in ONE quadrature sweep from a constitutive closure in the element's reduced Voigt space — computing both together is what keeps the tangent consistent with the stress, which is what quadratic convergence rides on. - materials::reduced_constitutive bridges the Material trait (Voigt-6) to that closure: 3-D passes the total strain straight through; 2-D supports the linear plane-stress closed form and refuses nonlinear materials explicitly, since plane-stress condensation of a general law needs a per-point iteration that is not implemented yet. - Dirichlet DOFs are held at their (load-scaled) values and Newton runs on the free DOFs, so the prescribed motion enters through f_int itself — no K_fc bookkeeping to get wrong. Body force enters via set_body_force, the same hook pattern the CFD solvers use for manufactured solutions. Uniform load stepping; other strategies and quasi-Newton refuse explicitly. - StandardFiniteElement::compute_internal_forces, previously a zeros stub, now delegates to the same machinery. - Mesh::validate is now called in run() (the old TODO), and NonlinearConfig gained a Default. Verified two ways (tests/nonlinear_static.rs): - Equivalence: with LinearElastic the loop lands on the directly assembled linear solution to 1e-10 in exactly one Newton step — same B, quadrature and solver, so any disagreement is the nonlinear assembly. - Manufactured solution with a genuinely nonlinear material (energy W = 1/2 e'De + alpha/3 I1^3, so stress and tangent are exact derivatives; body force by central differences of the closed-form stress): L2 errors 6.032e-2, 1.780e-2, 4.595e-3 on 2/4/8 Hex8 — observed orders 1.76 and 1.95, climbing to the theoretical 2. The forcing contains the nonlinear term, so the order is reachable only if it is solved; an inconsistent tangent is caught separately by the iteration-count bound. This unblocks ECSW model-order reduction, which needs a working nonlinear solve underneath it. 551 rtx-fea tests, 0 failing. Co-Authored-By: Claude Fable 5 <[email protected]>	2026-08-19 19:44:08 -07:00
Omar SobhandClaude Fable 5	87cf392556	rtx-fea: re-enable the remaining CPU test modules; fix three real defects they caught ... All 33 remaining #[cfg(disabled)] test modules outside the GPU cluster are now enabled: assembly (dof_mapping, constraints, global assembly), boundary (mod + dirichlet/neumann/robin/thermal/contact), analysis (mod + static), materials (mod, linear_elastic, hyperelastic, plasticity), elements (mod, element_matrices, isoparametric, jacobian, quadrature), mesh (element_types, connectivity, topology, topology_repair), solvers (mod, direct, iterative, nonlinear) and lib.rs. Lib tests 117 -> 335, stable across repeated runs. Only gpu_solver_tests and the GpuMeshData fixture stay disabled — they need CUDA hardware and belong to the GPU tranche. Three real defects found by the newly-compiling tests, each fixed: - Direct solvers reused factorizations keyed on matrix SIZE alone. In a Newton loop the Jacobian changes every iteration but never its dimension, so LuDirect/CholeskyDirect/LdltDirect silently solved with the first iteration's factorization forever — Newton on x^2-4 crawled to x=1.955 in 1000 iterations instead of converging in 5. Invisible in single-solve linear analysis, which is why every green test passed over it. solve() now factorizes the matrix it is given. - AdaptiveQuadrature's refinement re-integrated the WHOLE domain once per subdomain, so each level multiplied the estimate by the subdomain count: integrating e^x over [-1,1] at tolerance 1e-10 returned ~75 instead of 2.35. The recursion now descends into each sub-box with its share of the error budget. - compute_skewness read Jacobian columns as coordinate-line tangents, but the trait's jacobian() stores tangents in ROWS: on a sheared parallelogram whose tangents meet at 14 degrees it reported skewness 0.43 instead of 0.84 — measuring per-component gradients, not mesh skew. Fixtures corrected rather than the code where the fixture was wrong: sigma_yy ~ 0 asserted uniaxial-stress physics on a uniaxial-strain state (exact Lame values now asserted); an "unstable" orthotropic parameter set that satisfies the determinant stability condition (delta = 0.187 > 0); a unit-cube hex Jacobian of 1.0 that assumed a unit reference element (it is 0.125 from [-1,1]^3); a "distorted" quad whose centre Jacobian is exactly orthogonal, asserted as skewed (flattening and shearing now tested separately); a quality score below the implementation's own calibration; Rayleigh damping fed the scalar-field mass (now expanded via the Kronecker identity, with C = alpha*M + beta*K asserted entry-wise); an element factory required to construct Point/Line types that have no implementation; and DOF counts that encoded the repaired 3-DOFs-per-node-on-2-D defect. MaterialDatabase::add_material call sites updated to the (id, material, name) signature; ConnectivityInfo::build takes elements only; TopologyRepair::triangle_quality (normalized 4*sqrt(3)*A/sum(a^2)) added for the repair tests; create_subdomain_rule_* widened to pub(super) for the quadrature tests. Co-Authored-By: Claude Fable 5 <[email protected]>	2026-08-19 18:52:50 -07:00
Omar SobhandClaude Opus 5	698c844926	solvers: near-wall momentum, Newmark dynamics, QM6, and MMS across elements ... Four parallel work items plus two defects found while integrating them. 561 -> 592 tests, 0 failing, verified stable over repeated runs. ## rtx-cfd: solve the near-wall velocity lines Every u row sits at y = (j+0.5) dy and every v column at x = (i+0.5) dx -- strictly interior. The sweeps froze rows 0 and ny-1 and columns 0 and nx-1 and treated whatever was stored there as a boundary condition, which imposed wall values half a cell inside the domain. They are now unknowns, with the wall entering through the control volume's half-cell conductance (mu dx / (dy/2)), zero convective flux through the wall, and the wall's tangential velocity in the source. That in turn makes continuity enforceable on every cell, with a neighbour coefficient zero only for a genuine boundary face. Extending continuity had been tried before and broke convergence; it works now because the near-wall lines are no longer frozen. Order matters here. Manufactured solutions, which is how any of this is known: n L2 velocity order max |p - p_exact| 16 3.516212e-2 - 9.245576e-2 32 1.953751e-2 0.85 5.225739e-2 64 1.037523e-2 0.91 2.796415e-2 Velocity error is 7.4x smaller at n=16, and the observed order rises from 0.48 toward 1. The pressure error was 0.408 -> 0.624 -> 0.756, *growing* with refinement; it now falls. Divergence on the outer ring of cells goes from 1.0e1 to 2.5e-10. A separate defect found on the way: u_source_term was computed and never called, so the x-momentum equation carried no body force at all while the y-momentum one did. That is exactly the u-versus-v asymmetry the earlier diagnosis had flagged as an unexplained clue. Cavity at 65^2, against Ghia's u_min = -0.2109 at y = 0.4531: -0.1792 at 0.3906 before, -0.1932 at 0.5000 after, in 733 iterations rather than 971. The cavity test now sets FreeSlipWall on all four sides plus the lid through the new set_wall_velocity hook. That is not a weakened benchmark: on a staggered grid the only velocity component living *on* a boundary is the normal one, which is what FreeSlipWall prescribes, and the tangential no-slip arrives through the half-cell wall term with wall velocity zero on the three stationary walls. Prescribing whole u rows and v columns, as before, pins lines half a cell inside the domain and over-determines the cells beside them once every cell has a continuity equation. ## rtx-fea: DynamicAnalysis, previously a stub returning zeros Newmark-beta in acceleration form -- the displacement form divides by beta dt^2, singular at beta = 0 -- with Rayleigh damping, the effective matrix Cholesky-factorised once and reused. Initial acceleration is solved from M a0 = F0 - C v0 - K u0 rather than assumed zero, which would destroy the second-order rate. Verified two ways that cannot both be faked: against the closed-form single-degree-of-freedom response, undamped and damped, with the measured order of accuracy; and against the free-vibration period of the same bar whose modal frequencies are already validated. Time domain and frequency domain come from different code paths. ## rtx-fea: QM6 incompatible modes Wilson's Q6 with Taylor's correction, added alongside compute_stiffness_ matrix rather than replacing it -- the existing method is byte-identical, which matters because the manufactured-solution verification depends on it. Internal modes statically condensed; the incompatible strain block evaluated at the element centre, which is what makes the patch test pass on distorted elements. ## rtx-fea: manufactured solutions across the element library Quad4 order 2.00 Tri3 order 1.98 Quad8 order 3.00 Hex8 order 1.96 (new 3-D solution) Each element asserts its own theoretical rate. ## Two defects found while integrating Reverse Cuthill-McKee node ordering was nondeterministic. All three of its orderings -- seed selection, neighbour ordering, and the trailing sweep -- were decided by HashMap/HashSet iteration order, which std randomises per process. On a rectangular mesh every corner ties at minimum degree, so two calls to displacement_only on the same mesh in the same process returned different DOF indices for the same node, agreeing in only 5 of 20 measured runs. Ties now break by node id. This surfaced as a coin-flip test failure -- 12 in 25 runs -- and would have been dismissed as flaky rather than diagnosed had the integration pass not re-run it. Quadrature: triangle(3) weights summed to 0.25 against a reference area of 0.5, and tetrahedron(3) to 1/36 against a volume of 1/6. Both divided weights that were already tabulated for the reference measure by that measure again, so both rules integrated everything to a fraction of its value -- invisibly, since a scaled quadrature leaves the stiffness matrix symmetric, the mass matrix positive definite and the rigid-body modes exact. New test asserts every rule integrates 1 to its reference measure, across every family and order, plus Gauss-Legendre exactness to degree 2n-1. Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>	2026-08-19 15:39:20 -07:00
Omar SobhandClaude Opus 5	4c2cea36aa	rtx-fea: make the analysis stack produce physics, validated against closed form ... The census found rtx-fea could not produce a non-zero answer for any analysis type. Six defects sat between a correctly specified mesh and a natural frequency, each of which alone was fatal. Every one was found by writing the closed-form test first and confirming red. 1. Element matrices were a stub. StandardFiniteElement:: compute_element_matrices returned DMatrix::zeros for stiffness, force and mass -- and it is what GlobalAssembler calls for every element, so every global matrix in the crate was zero. Real quadrature-based stiffness and mass already existed in ElementMatrixComputer; nothing called them. Now wired, with the scalar mass matrix expanded by a Kronecker product with the spatial identity to match the interleaved per-node DOF layout its stiffness uses. 2. Quadrature returned no points. quadrature_rule built QuadratureRule::new(vec![], ..). Every integration loop iterates over rule.points, so an empty rule does not fail -- it skips the loop and yields a zero matrix. Real Gauss rules for line, triangle, quad, tet and hex existed unused; now dispatched by element type, with wedges as the triangle-line tensor product and pyramids an explicit error rather than an empty rule. 3. transform_derivatives computed J^-T * dN where dN is (num_nodes x param_dim). By the chain rule it is dN * J^-1. The two agree only when both are square and symmetric; for any element with more nodes than parametric directions -- every element -- the old form was a dimension mismatch that panicked inside BLAS. 4. MaterialDatabase::clone silently dropped every material, cloning names only, because Box<dyn Material> is not Clone. GlobalAssembler is constructed with materials.clone(), so every assembler ever built got an empty database and every analysis failed MaterialNotFound on a correctly specified mesh. Materials are immutable once registered, so the map now holds Arc and cloning shares them. 5. displacement_only numbered three displacement components on a 2-D mesh. Elements supply two, so assembly rejected every contribution. 6. to_dof_numbering pushed each node's DOFs in HashMap iteration order. When that came out [v, u] the assembler wrote the element's u row into the global v row. The result was still symmetric, still had the right rigid-body null space and still summed to the right total mass -- it simply described a structure with its axes transposed per node, and get_dof(node, DisplacementX) then pointed at the wrong row so constraints were applied to the wrong direction too. DofComponent now carries a canonical_index and the DOFs are sorted by it. ModalAnalysis is wired to real assembly and the repaired eigensolver, and takes boundary conditions, which it previously had no way to accept. The eigensolver now rejects a singular stiffness explicitly: try_inverse does not fail on a matrix singular only to working precision, so an unconstrained structure used to return rigid-body noise dressed up as low-frequency modes. Validation, 18 tests: - Element matrices: rigid translation stores no energy, exactly 3 rigid-body modes in 2-D and 6 in 3-D, consistent mass integrates to rho*V, mass positive definite, and K and M each scale only with the property they depend on. A zero matrix passes symmetry and does-not-crash checks, so these are chosen to be ones it fails. - Modal, end to end: longitudinal modes of a fixed-free bar against f_n = (2n-1)/(4L) sqrt(E/rho), within 1% on the first three, and second-order convergence under refinement. Axial rather than cantilever bending on purpose: Quad4 shear-locks, so a bending tolerance would fail for a reason unrelated to correctness. Bending is asserted as convergence from above instead, which is the honest claim for a locking element. Two fixtures corrected rather than tolerances loosened: integration_tests expected 27 DOFs for a 9-node planar mesh (3 components per node), which encoded defect 5 and contradicted comprehensive_tdd_tests asserting num_nodes * 2 for the same situation. rtx-fsi stays 26/26. No new failures; the rtx-cfd quarantine is unchanged. Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>	2026-08-19 08:10:57 -07:00
redclawsystems	4d88dc0584	Initial commit	2026-03-04 00:08:42 +00:00