Aerothermal analysis of the KRUPS space capsules

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. Previous analyses of the capsule has demonstrated that the flow around the capsule would be in the rarefied regime at altitudes higher than 60 km. This work focuses on hypersonic fluid simulations of the flow around the capsule at higher altitudes along the trajectory path. Direct simulation Monte Carlo simulations are performed at altitudes higher than 60 kilometers by accounting for thermochemical nonequilibrium in direct simulation Monte Carlo flow simulations. The flowfield at all altitudes exhibited significant thermal and chemical non- equilibrium with vibrational temperature lagging behind the translational temperature in the forebody. Temperature jump is observed at the surface, where the flow temperature at the wall does not accommodate to the surface temperature because of breakdown of continuum and the inception of slip effects. Computational fluid dynamics (CFD) simulations are also performed at five altitudes starting at 40 km, and decreasing in altitude to generate simulation results for comparison against flight data of the first KRUPS mission. Strong thermochemical non-equilibrium is present in the early part of the KRUPS re-entry trajectory, which is captured by the CFD simulations.