Aerothermal Analysis of a Sample-Return Reentry Capsule

The article deals with the aerothermal analysis of a sample-return hypersonic capsule reentering on Earth from an interplanetary exploration mission. The main objective of the work is to estimate the heat flux distribution on the capsule surface and to perform one-dimensional thermal analyses for its ablative heat shield. After a short review of sample-return missions, the numerical models implemented are described and the computational results, obtained along a feasible reentry trajectory, are presented and discussed. Particular attention has been paid to compare the convective stagnation point heat fluxes obtained by means of Computational Fluid Dynamic (CFD) analyses with the ones computed with engineering correlations. A further comparison between CFD and with Direct Simulation Monte Carlo (DSMC), in order to investigate the air rarefaction effects, is reported. The article shows an overall satisfactory agreement between engineering correlation and numerical results and also presents a preliminary dimensioning of the capsule ablative heat shield at the stagnation point.