P4.1 selected coupled requirements model — ready for publication verification.

Selected continuous event: 2790.7896 kg, 1.977413 s to 100 km/h,
26.285456 s to 400 km/h, 445.503750 m from 400 km/h to rest,
33.771 s for 0–400–0. Same fitted engine curve; 10 MJ chemical and
8 MJ DC exchange windows. Physical measurements: 0.

The replacement open-nitrogen power stage delivers about 0.90 MJ net during
acceleration, after its driving auxiliaries. Six kilograms of initial liquid
also pay for 0.819681 kg of prechill boiloff. Hot metal starts at ambient.
The engine-derived hot stream, nitrogen effluent, metal energy, pump/blower
work and ambient losses close both first-law and exergy identities.

Floor requests: 30 kN during launch (tapering by 150 km/h), 29.5 kN during
low-speed braking and 19 kN above 250 km/h, within the modelled map.
Nine standard cases and eighteen new held-out draws pass their computational
gates. Half-step stopping difference: -0.0098053 m. No extra tyre grip or
new-body CFD force benefit is credited.

Separate high-speed mode: about 480.3 km/h temporary scalar power-balance
peak, reserving the battery during a 43.6 s boost-off launch. It is not paired
with the quickest sprint time. Engine-only equilibrium: about 444.4 km/h.
The fast-sprint continuation cannot spend the entire requested 1 MJ pulse;
actual delivery is reported in top-speed.json. No resources reset at 400.

Unmeasured component maps and the drag-area target remain requirements.
New motor/gearing, fan installation, electrical packaging and structure are
not qualified by these equations or by the earlier P4.0 clearance study.

The published P4.0 archive remains frozen and unchanged.
R1 optimization history is retained in history/optimization-r1.zip.

Earlier airflow-development record follows; no force credit was accepted.

P4.1 exploratory airflow branch — no qualified body-force result.

Published P4.0 remains the corrected requirements model at https://cryopulse.org/research/p4/. Do not overwrite its source ZIP (SHA256 cd39b7149a8c2e93cdcabfe3cfbdddb74978b920ddb6d8174cb1f375f57c70e1).

SU2 8.6.0 official OpenMP binary is /tmp/cryopulse-su2/bin/SU2_CFD. Download ZIP SHA256 b306dcb7e76caec54e376542916aae14a32abd6c2f6fa8b871ec10ffe80b41ac. Official config and boundary-condition source references are under /tmp/cryopulse-su2.

SU2 SST initialization on the clean G0 tetrahedral geometry diverges with wall-function/energy issues. A first-order SA + Green–Gauss + isothermal 293.15 K startup is finite but has not converged by 2000 iterations. See output/solver-diagnostics.json; no forces are accepted. The inflated transient pressure/drag may involve non-tangential moving-wall velocities on the contact-pad approximation; that is a hypothesis, not an established bug. Official CNSSolver.cpp includes dynamic-grid pressure work proportional to wall velocity normal component.

star_stencils.py adds a cell-centre point and preserves surface triangles to add interior FV directions. The V5 one-cell split M0 remains below the determinant/weight criteria. No quality threshold was waived.

Potential next approaches: a contact geometry/wall-velocity treatment consistent with rolling motion, boundary-layer mesh construction, or a proper warm-start and convergence study. A new aerodynamic gain requires solver-appropriate mesh checks, grid/contact sensitivity, force convergence and a new continuous-event calculation. None is assumed from the concept artwork or a target CdA.
