docs: Dütsch protocol — fold the closed domain order, settling rule, window and criteria

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/validation/duetsch_re100_kc5_protocol.md

@@ -71,17 +71,24 @@ fixed before any benchmark result; it is not a paper uncertainty.
 
 ## 3. Domain and boundaries (finite-domain reproduction), ENGINEERING
 
-- Boundary family (runner owner confirms the zero-velocity inlet is supported
-  as configured before any run): the native dense channel only — zero-velocity inlet,
-  pressure-NEQ outlet, y walls (bounce-back). This is a finite-domain
-  approximation of the paper's 120 D O-grid, NOT infinite still fluid. The G4
-  periodic/slip overrides are a different family and are not substituted.
-- Sensitivity order (each step at D = 40 before the ladder is run):
-  1. box 24 D × 24 D vs 48 D × 48 D (cylinder mean position at the centre);
-  2. the larger box is accepted if section 6 domain criteria pass between the
-     two; otherwise 96 D is tried once (memory/runtime measured first); if that
-     still fails, the domain verdict is FAIL and is reported.
-- The ladder (D = 20 / 80) uses the accepted box size in units of D.
+The paper's 120 D O-grid is not reproduced; our rectangular box is a
+reproduction choice. The native dense channel (zero-velocity inlet,
+pressure-NEQ outlet, bounce-back y walls) is a finite-domain approximation,
+not infinite still fluid. The G4 x-periodic / y-slip override is a separately
+labelled sensitivity family and never mixed into the primary ladder. The
+runner owner confirms the zero-velocity inlet is supported as configured
+before any run.
+
+Order (closed):
+1. Smoke + ledger at D = 40, native BC, 40 D × 40 D (finite box).
+2. Domain sensitivity before any literature statement: same BC, D = 40,
+   L ∈ {20 D, 40 D, 60 D}; record the change in Fx waveform, c_d, c_i and the
+   scored profiles.
+3. Optional labelled BC sensitivity: one x-periodic / y-slip case at D = 40,
+   40 D; reported as a delta against native only.
+4. Only after step 2 passes: the D = 20 / 40 / 80 ladder on the chosen BC and
+   domain (default 40 D if, against 60 D, `RMS(dFx)/F_ref` and |dc_d|, |dc_i|
+   stay inside the section 6 bands).
 - Memory/runtime: measured by a smoke run before each new size; measurements
   inform scheduling only, never tolerances.
 
@@ -91,68 +98,75 @@ fixed before any benchmark result; it is not a paper uncertainty.
   CME + Wen and CME + cover − uncover reported separately; crossings, eq_only,
   no_donor (no_donor must stay 0).
 - Velocity u1, u2 on lab-fixed lines x/D = -.6, 0, .6, 1.2 (relative to the
-  mean cylinder position) versus x2, at every step of the scored phases.
+  mean cylinder position) versus x2, at the scored phases. Lab frame
+  throughout; if any body-frame intermediate is used, position and velocity
+  are both transformed.
 - Interpolation: bilinear on cell centres using only cells that are fluid at
   that step (flags read back via `get_flags()`); weights renormalized over the
   fluid corners; a sample with no fluid corner, or inside the circle at that
-  step, is MISSING and logged, never set to zero. One-degree bins carry only
-  valid samples.
+  step, is MISSING and logged, never set to zero. One-degree bins keep valid
+  fluid weights. The numerical average need not mimic the 200 LDA samples.
 
-## 5. Periodic-regime gate (every case, before any statistic)
+## 5. Periodic-regime gate (every case, before any statistic), ENGINEERING
 
-Ledger rows, same schema for every case:
+Ledger rows, same schema for every case: dx, dt (in D and T units); U_max, nu,
+Re, KC (lattice and nondimensional); T (native steps, nondimensional);
+duration (native steps, s/T, paper cycles); discard; accepted window; cycle
+ledger; verdict PASS or FAIL-CLOSED.
 
-| field | content |
-|---|---|
-| dx, dt | in D and in T units |
-| U_max, nu, Re, KC | lattice and nondimensional |
-| T | native steps and nondimensional time |
-| duration | native steps, s/T, number of paper cycles |
-| discard | cycle 0 plus all cycles before the accepted window |
-| window | the common accepted window (below) |
-| cycle ledger | per cycle k: phase-aligned waveform change and profile change (below) |
-| verdict | PASS or FAIL-CLOSED |
+Scales: `F_ref = 0.5 rho U_max² D`, `U_ref = U_max`; never a near-zero mean
+force as denominator.
 
-- Settling metric, ENGINEERING, fixed scales (no near-zero denominators):
-  - force: `max over phase of |F_k(phi) - F_{k-1}(phi)| / (0.5 rho U_max² D)`
-    on the per-step CME waveform aligned by step index within the cycle;
-  - profiles: `max over scored stations/phases/points of |u_k - u_{k-1}| / U_max`.
-- Rule: K_case = the smallest cycle k ≥ 4 for which both metrics are ≤ .005
-  for the N = 3 consecutive pairs (k-3→k-2), (k-2→k-1), (k-1→k).
-- Cap: 30 paper cycles per case; not settled by the cap → FAIL-CLOSED.
-- Common window: K = max over all compared cases of K_case; every case is run
-  to cycle K + 2 and scored on cycles K, K + 1, K + 2 (same indices).
-- FAIL-CLOSED also if any case covers fewer paper cycles than K + 2, if windows
-  differ, or if the ledger is missing.
+- Settling metrics, cycle k−1 → k, phase-aligned by step within the cycle:
+  - waveform `RMS(dFx) / F_ref ≤ .02`;
+  - `|d mean|`, `|d RMS|`, `|d peak|` of Fx, each `/ F_ref ≤ .01`;
+  - scored profiles (fluid-only) `|du| / U_max`, `|dv| / U_max ≤ .03` at the
+    three phases × four stations;
+  - Morison `|dc_d| ≤ .02`, `|dc_i| ≤ .02`.
+- Rule: all metrics for N = 3 consecutive whole paper cycles → settled.
+- Discard: the initial quarter cycle plus the first 2 full paper cycles
+  (s/T < 2.25). Settling is searched from cycle 3; cap 12 periods from s = 0;
+  unsettled → FAIL-CLOSED (no literature, cross-resolution or VIV statistic).
+- Common window: K = the largest first-settled cycle index over all compared
+  cases; every case is scored on the same 3 cycles K .. K + 2 and must reach
+  them within the cap (proportionally more native steps on finer grids), or
+  the comparison is FAIL-CLOSED.
 - The earlier G4 timing check (100 coarse vs 400 diffusive-fine steps) was a
   matched short transient, not periodic evidence.
 
 ## 6. Metrics and per-observable criteria (ENGINEERING, not paper uncertainty)
 
+Three criteria stay separate; the G4 same-grid 2% target is not reused.
+
 - Morison fit: least squares of the normalized per-step force over the
-  accepted window against the two basis functions above, each averaged over
-  its single step interval, fixed paper phase, no free phase shift; outputs
-  c_d and added-mass c_i per force candidate.
-- Criteria:
-  - cross-resolution: for each observable, the D20→D40→D80 differences to
-    D80 must decrease; force waveform: normalized RMS difference D40 vs D80
-    ≤ .02 (scale `0.5 rho U_max² D`); profiles: RMS D40 vs D80 ≤ .02 U_max;
-  - domain (section 3): same two norms ≤ .01 between the two box sizes;
-  - against Table 1 (computed reference): |c_d - 2.09| ≤ .06 and
-    |c_i - 1.45| ≤ .04 at D = 80 (our engineering bands; the table's own
-    96→384 change is reported alongside, not used as an error bar);
-  - against Fig. 8 LDA: QUALITATIVE ONLY. The original figure could not be
-    accessed or rendered (TRON 2026-10-30); no digitized ordinates and no
-    measurement uncertainty exist. No quantitative profile pass is claimed.
-    A quantitative criterion may be declared only after an accessible original
-    figure or data set and a documented digitization (figure, tool,
-    uncertainty) exist, and before that comparison is run.
+  accepted window against the two basis functions, each averaged over its
+  single step interval, fixed paper phase, no free phase shift; c_d and
+  added-mass c_i per force candidate.
+- Cross-resolution: every scored observable's error against its reference must
+  decrease monotonically D20 → D40 → D80 (necessary, not sufficient).
+- Against Table 1 (computed fit, not measured force): at D ≥ 40,
+  `|c_d - 2.09| ≤ .15` and `|c_i - 1.45| ≤ .15`, and monotone.
+- Force waveform against its own Morison reconstruction: residual reported
+  only, no pass/fail (the paper reports fit error above its coarse numerical
+  error and gives no percentage).
+- Fig. 8 LDA profiles: QUALITATIVE ONLY. The original figure could not be
+  accessed or rendered; no digitized ordinates and no measurement uncertainty
+  exist. After a digitization with figure number, tool and uncertainty note:
+  `RMS(|du|, |dv|) / U_max ≤ .15` at D ≥ 40 and monotone; LDA error stays
+  UNQUANTIFIED and is stated with every comparison.
+- Fy sanity (not literature): `|mean Fy| / F_ref ≤ .05` in the accepted window.
 - No force candidate is selected for an RHS by these results; each is
   reported.
 
+Superseded (earlier drafts): the velocity-jump start, guessed stations and
+phases, "C_M" for c_i, and the uncertainty wording; cycles 4–6, the 30-cycle
+cap and the earlier tolerance numbers.
+
 ## 7. Order and scope
 
-Protocol review → lean test driver (no production change; reuses the
-existing Simulation API) → smoke (memory/runtime) → domain sensitivity →
+Protocol review → one-shot Dütsch driver (analytic `set_body` + `run(1)`,
+cycle ledger, lab-fixed fluid-only station sampler, two-basis Morison fit; no
+reusable runner until the first smoke shows shared helpers pay off; no
+production change) → smoke (memory/runtime) → domain sensitivity →
 ladder → physical-validation verdict → only then single-cylinder VIV. No AMR,
 no pinball, no manuscript work.