Overflow Simulation Guidelines for Orion Launch Abort Vehicle Aerodynamic Analyses (Invited)

Abstract

The CFD solver Overflow was used to characterize the external aerodynamics of the Orion Launch Abort Vehicle at wind tunnel and flight conditions. The vehicle’s aerodynamics and recommended methods for obtaining good CFD accuracy are described. A grid generation system is used to create grids efficiently clustered in key regions, and grids of different resolution are routinely used to assess grid dependence. The ‘standard’ SST model in Overflow gives the best overall accuracy, which is generally good to very good. However, turbulence modeling is a primary remaining challenge for achieving good accuracy at wind tunnel conditions; several turbulence modeling issues are described. Nonunique behaviors in plumes, having physical origins but affected by numerical algorithms, are identified.