Ground-to-flight Extrapolation Under Uncertainty for High-speed Vehicles

Abstract

The challenges of reproducing high-speed flow and thermal loads simultaneously make it difficult to replicate hypersonic flight conditions in a ground test facility [1]. This complexity poses a significant challenge when designing the thermal protection system of atmospheric entry vehicles. Therefore, the Local Heat Transfer Simulation (LHTS) framework can be used to match the flight test’s stagnation point heat flux during the entry. The ground test and the flight test both have distinct features; therefore, this study evaluates the uncertainties in the LHTS-based simulations and associated disparities between ground and flight conditions.

By varying the Arrhenius pre-exponential constant in flight and ground tests to introduce uncertainty, the simulations were executed to verify if the LHTS framework is reliable in the presence of potential model error. The results indicate that ground and flight conditions both yield similar nominal heat fluxes at the wall. However, the uncertainty range for the flight and ground conditions differs, exhibiting significantly larger variability for the flight condition.