Computational study of a lunar return aerobrake concept

The flow field around a proposed lunar return aerobrake is examined computationally assuming viscous, laminar flow and utilizing an effective gamma approach to incorporate real-gas effects. The flow fields for three cases are calculated with both an axisymmetric and a three-dimensional formulation. The three vehicle configurations have braking panels extended 50 deg, 55 deg, and 60 deg to the inflow (zero lift configurations). The resulting axisymmetric and 3D flow fields are examined, and it is shown that despite complexities in the 3D flow field, the total drag coefficients calculated from modified axisymmetric results are very close to those obtained from the 3D solutions. The aerobrake is shown to achieve total drag coefficients as high as 8.4 for a vehicle with panels deflected to 60 deg.