On the interaction between a rigid parachute and the supersonic wake behind a probe during the descent phase on Mars*

The number of recent missions on Mars highlights the renovated importance of this planet exploration. Nevertheless, recent and past failures clearly show how critical the landing phases are for these missions. Entry and descent phases of interplanetary probes are characterized by complex aerodynamic phenomena as the capsule gradually encounters the planet's atmosphere. In the present study we use accurate 3D Large-Eddy-Simulations to simulate the interaction between the wake behind the probe and a rigid parachute in a supersonic regime matching the typical Mars descent conditions. Firstly, the supersonic wake behavior will be characterized in terms of fluctuation intensities, typical frequencies and a Proper-Orthogonal-Decomposition analysis. Then the interaction between the wake and the parachute will be discussed. We will show how the unsteady turbulent wake forces the breathing of the bow shock in front of the parachute causing strong unsteadyness of the aerodynamic behavior. We will also discuss a simple model able to capture this interaction well reproducing the main flow features. More details will be given in the final paper.