Computational Fluid Dynamics Analysis of the Kentucky Re-Entry Universal Payload System

Abstract

The Kentucky Re-Entry Universal Payload System (KRUPS) is a low-cost space capsule that has been designed to collect flight data. This work focuses on computational fluid dynamics (CFD) simulations of the flow around the capsule at various altitudes along the trajectory path during Earth re-entry. CFD simulations are performed at altitudes of 60 and 40 km by accounting for thermochemical nonequilibrium and surface catalycity using current state-of-the-art hypersonic approaches. The flowfield at all altitudes exhibits significant thermal and chemical nonequilibrium with vibrational temperature lagging the translational temperature in the forebody and exceeding the translational temperature in the wake. Inclusion of surface catalycity influences the heat flux on the surface and the flow temperature in the boundary layer. The number density profiles of nitric oxide molecules and spectral emission computations using the line-by-line radiative solver NEQAIR indicate that higher emissions would occur at an altitude of 60 km in comparison to emissions at 40 km, and spectral intensity would be higher along the stagnation line despite high densities of NO near the edges of the capsule, and that emissions in the 100–400 nm wavelength range are dominant.