ANSYS Fluent Scale-Resolving Simulations with SBES & Validation of a Re-Entry Capsule at Hypersonic Speed

This paper outlines the results of simulations of an experimental configuration from the CUBRC test facility of a spherically blunted re-entry capsule model that is representative of NASA's Orion crew module. The primary interest of this study is in the prediction of the afterbody wake flow. In the wake, massively separated and highly unsteady flow conditions dictate the aerothermal loads experienced on the vehicle surface. These flow conditions have proven challenging to simulate with the accuracy required for use in the design of such capsules, in particular their thermal protection systems. Unsteady Reynolds-Averaged Navier-Stokes (RANS) techniques have proven insufficient, pointing to the need to resolve the large turbulent structures that dominate the turbulent mixing and associated heat transfer. The focus of the simulations presented here is the use of a novel scale-resolving model called Stress-Based Eddy Simulation (SBES) on such a hypersonic flow configuration, in this case for a Mach number (M) of 6.41 at an angle of attack (α) of 28o. The Ansys Fluent scale-resolved results are compared to experimental measurements of pressure and heat transfer over the capsule surface, as well as against steady-state RANS solutions to establish the benefit of the scale-resolved approach using the SBES model. In addition, the simulations explore the use of all-polyhedral meshes with different resolutions and strategies for this type of application.