Audit-First Haemodynamic Navier-Stokes CFD I: 2D Steady Flow on Synthetic Vascular Geometry (Reproducibility Contract)

This record presents an audit-first haemodynamic Navier-Stokes CFD protocol for Route A in a minimal steady-state design-comparison setting. Its purpose is not to make clinical claims, but to define a reproducibility contract for haemodynamic simulation outputs on synthetic vascular geometry under fixed boundary conditions and a fixed solver configuration. The governing rule is straightforward: the same inputs, the same boundary conditions, and the same solver configuration must yield the same outputs. To make this enforceable, the record treats geometry, boundary conditions, solver identity and version, mesh configuration, numerical scheme, outputs, and run log as explicit artefacts within a ledger-based…