Aerothermodynamic environment of the Beagle2 entry capsule

This paper summarises the aerothermal analysis performed in support(1) of the Beagle2 capsule design. Analysis has concentrated on providing heat flux data for both the fore body and after body TPS in a format suitable for TPS design activities. A new engineering correlation was defined for the rear TPS based on 2D axisymmetric Navier Stokes solutions which caters for the second heating peak observed in previous US Mars entry flight data and CFD analyses. Caution is necessary when using the cfd derived correlations in areas of separated and re-attaching flow due to large variations at even modest angles of incidence and with detailed based geometry. To increase confidence a limited number of experiments were undertaken to provide CFD validation data. Resulting experimentally derived fluxes were within the expected accuracy of the predicted values for the forebody TPS, and below predictions for the afterbody TPS An initial evaluation of the BEAGLE2 TPS erosion due to the presence of dust in the atmosphere of Mars is presented. While heating levels appear to be unaffected, the level of erosion is of the same order as the char thickness for nominal clear atmosphere while the virgin material is likely to suffer sonic erosion in dust storm conditions. There are large uncertainties associated with the analysis in terms of atmospheric density and erosion performance of the ablation material. This latter aspect could be addressed with suitable ground based experiments.