DSMC Aero-Thermo-Dynamic Analysis of a Sample-Return Capsule

摘要

A rarefied aero-thermo-dynamic analysis of a sample Earth Return Capsule during the high energy, high altitude re-entry path from an exploration mission is presented. The altitude interval 70-120 km is considered, where the capsule experiences different flow fields. In fact, the flow regime ranges from continuum low density to near free molecular flow and, even though the free stream velocity is almost constant (13 km/s) in the whole altitude interval, the Mach number changes from 44 to 32 and the Reynolds number, based on the capsule diameter, ranges from 4.92×10~4 to 9. The computations have been carried out using two direct simulation Monte Carlo codes: DS2V to compute local quantities such as heat flux, thermal and aerodynamic loads at zero angle of attack and DS3V to compute global aerodynamic coefficients in the range of the angle of attack 0-60 deg.. The results verified that in this altitude interval the heat flux and the thermal load reasonably satisfy specific requirements for the thermal protection system and that the capsule is longitudinally stable up to an angle of attack of about 40 deg..