Paper 152E: Misalignment-Branch Robustness of the N = 192, dt/2 Scale–Pinch Response Tuple in High-Vorticity Navier–Stokes Flow

Paper 152E tests whether the N = 192, dt/2 scale-pinch response tuple remains stable when a small misalignment perturbation is added to the high-vorticity Navier-Stokes audit. The tested branch uses epsilon_misalign = 0.03, viscosity nu = 0.00125, amplitude A = 1.0, time step dt = 0.0005, final time t_final = 2.0, and seeds 101, 202, and 303. The purpose is narrow: to determine whether the misaligned branch preserves the same route-response class observed in Paper 152D for the unperturbed branch.

The audit tracks cube concentration, admissible coherent stretching fraction, normalized pinching response, and active stretching throughput. Across the three completed cases, the median values are q_cube = 1.4263, q_ball = 1.7838, F_adm = 0.0300, Q_kappa / P_plus_Omega_kappa = 439.12, and Gamma_stretch = 0.1877. The maximum CFL median is 0.1775, and the symmetric enstrophy-balance residual median is 0.00263. These values satisfy the declared pass criteria: concentration remains critical or subcritical, admissible coherent stretching remains low, pinching response remains large, and throughput remains active but bounded.

The cube-ball cross-check uses six saved vorticity-magnitude snapshots and finds no geometry contradiction: all q_ball values remain below the declared 2.2 audit band. Threshold sweeps, raw numerator-denominator checks, route-timing tables, and numerical-fidelity diagnostics support the same conclusion. The misalignment perturbation does not reveal a clean coherent stretching escape, does not collapse the pinching response, and does not open a high-throughput route.

This paper does not claim a Navier-Stokes regularity proof, does not modify the Navier-Stokes equations, and does not promote measured diagnostic scales into theorem-level constants. Its contribution is a targeted robustness result: the N = 192, dt/2 scale-pinch response class survives the epsilon_misalign = 0.03 branch, preparing a later six-case synthesis with the unperturbed Paper 152D branch.