High-fidelity simulation of a supersonic parachute for Mars descent

The project aims to characterize the unsteady dynamics of the parachute-capsule in a supersonic flow during the descent phase on planetary entry. Presently, Large-Eddy Simulation in combination with an Immersed-Boundary Method is employed to analyze the time-evolving flow of a rigid supersonic parachute trailing behind a reentry capsule during the descent phase through Mars atmosphere. The flow is simulated at Ma = 2 and Re = 106. A massive GPU parallelization is employed to allow a very high fidelity solution of the multiscale turbulent structures present in the flow that characterize its dynamics. We show how the interaction of wake turbulent structures with the bow shock produced by the supersonic decelerator induces strong unsteady dynamics. This unsteady phenomenon called ‘breathing instability’ is strictly related to the ingestion of turbulence by the parachute’s canopy and is responsible of drag variations and structure oscillations observed during previous missions and experimental campaigns. The next steps will take into account the flexibility of the parachute.