Flux method analysis of flow patterns and aerodynamic characteristics during separation of front heat shield from re-entry vehicle

The paper discusses the results of numerical simulation of jet flows of the landing multi-nozzle propulsion system of a segment-cone-type reentry vehicle during interaction with the landing surface. Computed are both the flow of jets spreading over the surface and the flow in the vicinity of the vehicle induced by them. The studies were done for several distances between the landing surface and reentry vehicle. For each case the steady-state solution was computed. Determined were the time needed for the flow to reach the steady state and the values of the perturbing aerodynamic forces caused by the flow of the surrounding air caused by the induced stream flow. Uniform dependence of these values on the distance to the landing surface was obtained. In the configuration under review the position of the propulsion system nozzles on all the surfaces of the reentry vehicle there is a negative pressure creating a force which reduces the thrust of the propulsion system in the vertical direction. Generated in the process is a stream of gas from the jets, directed towards the frontal part of the vehicle. Computation was done for the case where the long axis of the vehicle deviated from the vertical. Flow pattern was obtained and the effect of the jets on aerodynamic characteristics was evaluated. The effect of a reduction in the thrust on the parameters under study was investigated. Under consideration were the effects of reductions in thrust produced by both lower pressure in the jets and by a proportional reduction in their cross section. The spatially unstable flow structure is visualized. The numerical simulation is based on a conservative finite-difference flux method. The computation is performed using parallel algorithms implemented on a cluster-architecture supercomputer.