Validation of Multi-Temperature Models for Hypersonic Flows

In this study, a computational framework for the simulation of high-enthalpy hypersonic flows is assessed using the multi-temperature Navier–Stokes solver NExT. Numerical simulations of hypersonic flow over spherical geometries are first performed to evaluate the numerical setup and the capability of multi-temperature thermochemical non-equilibrium models to reproduce experimentally observed shock standoff distances. Two sets of ballistic-range measurements from the literature are used for validation in air and CO2 environments. The methodology is then applied to the simulation of the Apollo capsule under continuum reentry conditions. Aerodynamic coefficients and wall heat-flux distributions are analyzed through a grid-convergence study, and the predicted aerodynamic coefficients are compared with reference results available in the literature. The simulations show very good agreement with previously published Navier–Stokes solutions, confirming the reliability of the adopted modeling approach. The results highlight the importance of accurately capturing thermochemical non-equilibrium effects and provide an assessment of the predictive capability of the multi-temperature model in hypersonic regimes, supporting its application for validating hypersonic entry-flow predictions relevant to planetary atmospheres.