Can a starting vortex boost the turbulent transition of a Richtmyer-Meshkov instability-induced air/helium mixing zone?

International audienceThis work is part of the study of the turbulent mixture produced by the Richtmyer- Meshkov instability. It focuses on the characterization of the initial conditions and on their persistence when the mixing zone develops into a turbulent flow, in other words the so-called initial condition memory effect. A Direct Numerical Simulation of the flow arising from the rotation of series of blades initially separating two gases of different density is conducted. The analysis relies on the impact of the resulting vortical flow on the generation of a more or less diffused and disturbed initial gaseous interface as the rotational speed of the blades is varied. Results highlight different flow regimes, associated with the redistribution of the total vorticity between the different vortex cores promoted by the opening of the blades, as both the rotational speed and the gaseous medium in which the blade tips are moving into vary