63 Commits

Include renames

Author	SHA1	Message	Date
Omar SobhandClaude Fable 5	992cd76449	rtx-fsi: stall acceptance as a knob (STALLX) — the floor must stay tight; only the rare-event window widens ... FSI3's developed cycle stalls (bistable mask flips at max-velocity crossings) sit at 3.5e-4 against the measured floor 6e-5: run 3 died 16% over the 5x window at t = 7.70. Riding the FLOOR up instead was measured to make it worse — run 4 at floor 1e-4 died EARLIER (t = 6.30) at a HIGHER stall (1.2e-3, 2.4x its window), because the accepted-step scatter IS the wall-velocity noise (tol/dt_c): a looser floor feeds the flip noise it is trying to pass. Keep the floor tight and widen only the counted, bounded stall window: `stall_accept` (RTX_<CASE>_STALLX, default 5 — both committed defaults bit-identical). Precedent: FSI2's s = 1 benchmark run accepted a worst stall of 5.4e-4 the same way and measured 0.1% in amplitude. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-25 05:00:56 -05:00
Omar SobhandClaude Fable 5	647f247601	rtx-fsi: report Newton rescue counts in the coupling-failure panic ... FSI3 run 3 died on a coupling stall 0.2 s after the rescue carried it past run 2's Newton death, and the panic path printed nothing about how many rescues had engaged. Observability only — the panic message now carries rescue_counts. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-25 01:07:49 -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	555a72cbc0	rtx-fsi: spike-clamp the force-measurement probe ... measure_force integrated raw traction samples while the coupling loads carried the 20x-median clamp — so the s = 1 benchmark run's REPORTED drag/lift were +-4,000-scale garbage against a +-78 reference while its displacements matched the benchmark to 0.1%. Collect, clamp, then integrate, both probes. Reporting only: the committed FSI2 default reproduces its trajectory to every printed digit (uy 3.7732 / 3.7920 mm) and its rigid-phase drag (121.4) with the clamp in. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-24 05:59:18 -05:00
Omar SobhandClaude Fable 5	c1bcdc408e	rtx-fsi: FSI3 floor 6e-5 — the floor rides with the motion; measure it through the cycle ... The first subcycle-2 study (t = 4 -> 8) ran 2.2 s of cycle — over [5, 6] s: +-42.8 mm at 6.2 Hz, trending toward the reference +-34.9 mm at 5.46 Hz from above — then stalled at t = 6.18 s: residual 1.9e-4 against an accept window of 1.5e-4 (5 x the 3e-5 floor the rest-state probe suggested), at a turning point of the cycle where the step increment, and with it the increment-relative part of the window, collapses while the flip noise does not. Floor set from the cycle's measured stall level (window 3e-4). Default re-verified: 581 steps, 3.5 subit/step (max 5), 0 stalls, conservation 1.5e-12, ux -2.90 +- 2.93 mm vs reference -2.86 +- 2.70. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-23 23:41:02 -05:00
Omar SobhandClaude Fable 5	c0666bf22a	rtx-fsi: C3 — FSI3 opened: the added-mass regime, its impulse artefact, and the coupler hygiene it demanded ... The march is extracted from the FSI2 test into a shared tests/fsi2_harness/march.rs (MarchConfig from env / MarchResult / window statistics), the harness parameterised by BenchmarkCase (FSI2, FSI3: inflow, solid density, modulus, rigid-flag drag reference), and turek_hron_fsi3.rs written on top (Re 200, density ratio 1, E 5.6e6). The committed FSI2 default is bit-identical through all of it — every new knob defaults to FSI2's behaviour; re-verified twice to every printed digit (uy 3.7732 / 3.7920 mm). FSI3's first contact, traced pass by pass (RTX_FSI3_TRACE), exposed the added-mass instability in its purest form and, one measured mechanism at a time, what a partitioned coupling at unit density ratio needs: - C^1 interface motion (MarchConfig::c1_interface): a constant per-step interface velocity is a velocity JUMP at each step start, and the incompressible fluid answers with an impulsive added-mass load ~ rho L dv / dt_fluid (8x the physical reaction under subcycling): 1,600 N at release, 48,000 N and a 59 mm response one step later, the flag's Newton dead the pass after. Constant acceleration from the previous end velocity to 2 dd/dt - v_n removes the impulse (loads 1,700-2,400 N). - IQN first-pass relaxation as a knob (initial_relaxation, FSI3 0.05): |1 - omega (1 + g)| must contract; 0.5 diverges past gain 3. - The divergence verdict waits for the secant (IqnIls): the exploratory second pass on a high-gain map legitimately overshoots 10x before the first secant column exists. Pinned by a gain-40 model test. - Kinematic predictor (predictor: "kinematic", velocity only): the structure-alone predictor ignores an added mass comparable to the flag's and overshoots 2-5x, drawing 5-6x loads every first pass; and NOT with the acceleration — Newmark average acceleration carries an inconsistent initial acceleration as a sign-alternating mode (d + dt v + dt^2 a / 2 predicted 22 mm at release; converged 0.14). - Quiescent release (quiescent_release): the structure-alone "consistent" initial acceleration M^-1 F ignores the added mass. - Coupler hygiene (IqnIls): a stalled or diverged step's secant columns are no longer retained (a bistable mask flip's columns extrapolated a 30 mm interface jump on the next step); two-window stagnation detection reports a plateau early instead of bouncing to the budget (a single-window test misjudged a slowly converging step and is recorded as such); trust region tightened to 10x the residual. A noise-column filter at the tolerance was measured to HURT (stalled a converging step at 5.5e-4) and is disabled (threshold 0). - The floor measured, not borrowed (fsi2_interface_noise.rs gains RTX_NOISE_CASE=fsi3): flip jumps 3.6e-4 (12x FSI2's), the subcycle-8 release map stalling near 1e-6, the subcycle-2 map converging to 9e-10; and through the release transient (flag at ~0.3 m/s) the subcycle-8 floor rides up to ~1e-3 with the motion — which moved the FSI3 default to subcycle 2 at a 3e-5 floor. FSI3 committed default (ny 62, release t = 4, t_end 4.2, subcycle 2): 581 steps, 3.8 subit/step (max 8), 0 stalls, 0 retries, conservation 4.3e-13; uy 10.1 +- 27.5 mm and ux -3.1 +- 3.2 mm over the first 0.2 s (reference cycle 1.45 +- 34.90, -2.86 +- 2.70). Machinery invariants pinned; physics bands await the study record. Rigid-flag drag 426.9 vs CFD3's 439.45 (-2.9%). The FSI2 mode-2 study pin (IQN / subcycle 2, t_end >= 16) was measured with the pre-hygiene coupler; re-verify on the next s = 2 study run. 48 lib tests green, clippy clean. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-23 19:43:02 -05:00
Omar SobhandClaude Fable 5	be04e0e233	rtx-fsi: pin the mode-2 flapping cycle under the IQN / subcycle-2 configuration ... Study horizons (t_end >= 16) under RTX_FSI2_COUPLER=iqn RTX_FSI2_SUBCYCLE=2 now assert the measured mode-2 cycle: frequency in [2.05, 2.45] Hz and uy amplitude in [45, 70] mm — bands that admit the settled cycle at either grid (ny=62: 57.6 mm / 2.227 Hz at t=16, 55.9 / 2.224 at t=30; ny=82: 57.1 / 2.236 at t=20) and reject both the wake attractor (3.73 Hz, ±17 mm) and the reference itself (1.93 Hz, ±82 mm) as material changes. The default configuration's pins are unchanged. Module docs brought up to the eleventh-session record. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-23 16:54:12 -05:00
Omar SobhandClaude Fable 5	a342e703a4	rtx-fsi: trust-region cap on the IQN step + increment-scaled stall acceptance ... The s = 1 FSI2 march (deepest rung: 1.955 Hz, ±73 mm mid-growth) found two coupler failure modes at peak motion: - run 1 (budget 12): NotConverged at residual 6.1e-4 = 9% of the step's own increment, after the history-reset retry — killed at t = 11.1 s. - run 2 (budget 30): the deeper budget let an ill-conditioned secant model extrapolate the locally violent map into a candidate interface that swept to the domain wall and crashed the mask build BEFORE any residual guard could fire (t ~ 9.9 s). Fixes, both scale-relative per the absolute-threshold rule: - STEP_CAP = 50: the full quasi-Newton step r + W alpha is capped at 50x the current residual norm, direction kept. Legitimate large Newton steps (near-marginal gains) pass; thousand-fold geometric extrapolations cannot. Pinned by a noisy-map test asserting every iterate's step stays within the cap. - The march accepts a stalled step at residual < max(5 x tolerance, 0.1 x the step's own increment) — the rare violent step near peak motion carries an order-below-increment error, counted like every stall and bounded by the existing stall-fraction assert; the retry trigger mirrors the same bound. 46 lib tests green, clippy clean. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-21 19:14:53 -07:00
Omar SobhandClaude Fable 5	d5f19ea497	rtx-fsi: IqnIls::reset_history — stale secant columns overshoot in rapid transients ... The s = 2 ladder march (resonant growth finally open: 2.3 Hz, amplitude through ±46 mm — 2.7x the wake attractor the loose coupling locked) died at t = 11.12 s with CouplingDiverged at iteration 2: the predictor left a 1e-4 first residual, and the first quasi-Newton update drove it to 1.1e-3. Cross-step secant history assumes the interface Jacobian drifts slowly; columns recorded at much smaller amplitude steered the least-squares direction wrong at 2.7x that amplitude, and the divergence guard read the overshoot as added mass. The map itself converges deeply from a clean start (the noise probe's stall measurement), so the recovery is: reset the history, retry the step once from the predictor. - IqnIls::reset_history(), with a cold-start-equivalence test. - turek_hron_fsi2: on an unaccepted coupling verdict under the IQN coupler, reset + one retry from the predictor (Aitken carries no history — a retry would repeat the identical iteration, so the path is IQN-only); retried steps counted and reported like stalls. Verified end-to-end: the re-run crossed the killing step and marched on (t = 11.18: uy +56 mm, window amp ±50 mm, 1.4 subit/step). 45 lib tests green, clippy clean. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-21 09:34:10 -07:00
Omar SobhandClaude Fable 5	140310b223	rtx-fsi: the noise floor interrogated — smoothing refuted, IQN-ILS lands, tight coupling reopened ... The tenth session ended on "lower the interface noise floor". This builds the levers and measures them, and the measurements overturn the diagnosis: - smooth_tractions: arclength moving average over the wetted surface, area-weighted, smooth normal-similarity factor so corners do not mix and the smoothed load stays continuous in the geometry. Nine unit tests. MEASURED NEGATIVE RESULT: the flip-scan floor is unchanged to 0.2% at radii 1-3h — the flip's load jump is coherent through the fluid field (mask rebuild shifts the pressure around the flipped cell), and a surface average preserves coherent shifts. Default off; the probe pins the attribution so nobody re-reaches for this lever. - IqnIls: interface quasi-Newton with inverse least squares (Degroote 2009) — filtered MGS least squares over secant columns (filter RELATIVE to column norm), cross-step history reuse, per-step set_tolerance. Model-map tests: exact on anisotropic linear maps within dim+2 passes (scalar Aitken provably cannot be), scale invariant, history reuse shortens the next step, stalls at the noise scale instead of diverging (fixture lesson: per-pass noise, not state-dependent noise — the latter has a genuine fixed point). - tests/fsi2_harness/: the FSI2 machinery extracted shared; verified pure code motion (committed release response reproduced to every printed digit). March gains RTX_FSI2_SMOOTH / RTX_FSI2_COUPLER=iqn / RTX_FSI2_REUSE knobs; pinned bands guard the default configuration. - tests/fsi2_interface_noise.rs: the probe. Flip-scan floor at subcycle 8: 3.05e-5 (pinned); smoothing attribution pinned; the cross-subcycle scan recorded but unpinned (the fixed geometry increment's wall-velocity trend, increment/dt_c, swamps the flip signal at small dt_c — a dt_c^2 scaling hypothesis died in that operationalization). THE OPERATIONAL FLOOR — the real release step subiterated at tolerance 1e-9 with residuals traced — converges DEEP at both subcycles: s8 aitken 3.4e-9 / iqn 1.6e-9, s2 both ~6.4e-10 in 5-6 passes. The flip jumps are events at specific geometries, not a floor under every step: the tenth session's subcycle-2 blowup was tolerance mis-budgeting (2e-4 held fixed while dt_c shrank), not an impassable floor. Probe bug found and fixed on the way: stale shared geometry leaked a 4.5e-5 phantom first residual into the first stall run; every measurement now resets the geometry on entry. All 924+17 tests green: lib 44 (was 27), piston 2, curved edge 1, FSI1, the committed FSI2 march (release response identical), the probe. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-21 06:42:05 -07:00
Omar SobhandClaude Fable 5	4e90177aa9	rtx-fsi: C2 — FSI2's coupled march, and the wrong attractor measured ... The unsteady coupling on the piston pattern with the real solvers: per TIME STEP, Aitken subiterations of (8x-subcycled embedded TVD/multigrid fluid <-> flag nonlinear-Newmark step), the fluid re-runnable through snapshot/restore + a field clone, the flag re-runnable because the stepper commits nothing, the moving polygon carrying the flag's actual interface velocity. Conservation 8.3e-12 over 9,263 coupled steps; the rigid phase reproduces this solver's own CFD2 values at both grids before anything couples. What the 30 s studies measured (ny = 62 AND 82, three protocols): the coupled system self-excites into a wake-forced cycle at 3.729/3.728 Hz with uy(A) +-17.3 mm at both grids - grid-converged, protocol- independent, kinematically genuine (ux locks 2x uy) - and NOT the benchmark's mode-2 resonant cycle (1.93 Hz / 81.6 mm; the flag's vacuum mode 2 is 1.9245 Hz). Diagnosis measured stepwise: the staggered phase lag starves the resonant channel (a subcycle=2 probe redirected growth to 1.9 Hz as predicted), and tighter dt_c is blocked because wall- velocity noise = displacement-tolerance / dt_c while the needed tolerance sits below the discrete interface noise floor (~1.3e-4 at full inflow, mask flips through beta dt^2/m). The route to the benchmark cycle is lowering that floor, not iterating against it. Robustness, both measured: rare wild tractions (19 samples in 2.4M) clamped at 20x the sample median - clamped, not dropped: a hard drop makes the pass discontinuous and the subiteration bounces at step scale; and Aitken "divergence" verdicts within 5x tolerance accepted as noise bounces over well-predicted steps (counted, bounded). The committed default (t_end = 7, ~9.5 min) pins the deterministic release response (uy 3.773 +- 3.792 mm, band +-35%); study horizons >= 25 s pin the measured 3.73 Hz attractor so any material change is loud. Full study record in the module docs and omni-cortex solver_status.md. Co-Authored-By: Claude Fable 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Lnyrw33Lu6rUhW42E9KHwq	2026-08-21 02:45:43 -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	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