Computational Fluid Dynamics Analysis of the Orbital Flight of the Kentucky Re-Entry Universal Payload System (KRUPS)

The Kentucky Re-Entry Universal Payload System (KRUPS) orbital flight vehicle is a low-cost space capsule that has been designed to provide flight data for validating modeling tools. This work focuses on hypersonic computational fluid dynamics (CFD) simulations of the flow around the capsule at various altitudes along the trajectory path. CFD simulations are performed at altitudes of 40, 60, and 80 kilometers by accounting for thermochemical nonequilibrium and surface catalycity using current state-of-the-art hypersonic approaches. The flowfield at all altitudes exhibited significant thermal and chemical non-equilibrium with vibrational temperature lagging behind the translational temperature in the forebody, but higher in the wake. Inclusion of surface catalycity influenced the heat flux on the surface, and the flow temperature in the boundary layer. Surface catalycity shifted the shock stand-off distance at 80 km by 20%. Additionally, the heat flux predicted using a partially catalytic wall at 80 km was higher than the heat flux obtained using a fully catalytic wall demonstrating that a fully catalytic wall need not be the upper bound for heat flux under all flow conditions. Finally, the NO number density profiles indicated that higher radiative emissions would occur along the outer edges of the capsule.