Radiative heating analysis of a Mars entry capsule based on narrow-band K-distribution method

Abstract

Radiative heating of a Mars entry capsule was evaluated along a reconstruction trajectory. Reactive flows were computed using a three-dimensional computational fluid dynamics (CFD) solver. Based on the narrow-band k-distribution (NBK) method, a new seven-point radiative property database was established relying on the line-by-line (LBL) approach. The CFD solver and the radiative model were verified by use of the experimental data. Some issues were numerically studied including flow field parameters, radiative heat fluxe (RHF) at forebody and afterbody, and contribution of radiative heating to aero-heating. The results reveal that the high RHF region is distributed in the windward side of the forebody and the leeward side of the afterbody. A comparison between the RHF and the convective heat flux (CHF) shows that the contribution of the RHF has a noticeable increase at low-altitude trajectory points. The maximum increase of the RHF reaches up to 45% of the total heat flux. In addition, the computational results without the angle-of-attack (AOA) indicate that the AOA has a less than 20% influence on the maximum RHF. These computational results provide a guide for the design of the thermal protection system (TPS) of Mars entry capsules.