Simulation of a Mars aerocapture vehicle on flow adapted unstructured grids with the DLR TAU code

Abstract

In this work both flowfield and radiation transfer solutions are presented for the TC3 Mars Sample Return Orbiter (MSRO) aerocapture vehicle. The hybrid grid capability of the DLR-TAU code has been implemented to calculate the flowfield surrounding the vehicle with a particular emphasis on accurately capturing the relevant wake flow structures while minimising the grid size. A novel Monte-Carlo based radiation transport algorithm incorporating opacity binning of the spectra is described, validated and applied to solve for both the radiative heating at the surface and divergence throughout the flowfield. The majority of the radiative heating is calculated to come from the CO2 rovibrational bands at 2.7 and 4.3 μm. Implementing a fully catalytic vehicle surface results in a CO2-rich boundary layer that expands into the wake region, influencing the afterbody radiative heating. The computed radiative heating profiles for the non-catalytic case are between 2 and 3 times higher than previously published solutions. Possible causes of this overprediction are discussed.