Two-stage RANS-DDES model and results of computations of unsteady loads on reentry capsule and engine compartment of manned spacecraft in the course of their emergency separation

Two-stage RANS-DDES model and results of numerical simulations are presented of transonic and supersonic turbulent flow over a manned spacecraft in the course of separation of the reentry module after actuation of the propulsion device of the crew emergency rescue system in the initial flight stage. The study is focused on determining the unsteady aerodynamic and aeroacoustic loads on the screen of the reentry module and on the screen and fairing of the engine compartment. It is shown that the maximum level of the unsteady loads is reached on the fairing of the engine compartment in the region of impingement of turbulent structures populating the shear layer separated from the command module. Other than that, it is found that at the transonic flight in the initial stage of the detachment process, self-exciting oscillations are observed in the gap between the reentry module and the engine compartment.