Shock unsteadiness in a shock-wave / boundary-layer interaction - Prof Jean-Christophe Robinet

We are going to have a seminar on 'Shock unsteadiness in a shock-wave / boundary-layer interaction' on 16th July 2014, Wednesday, given by Prof Jean-Christophe Robinet, DynFluid Laboratory - Arts et Métiers ParisTech

Abstract is given below.

Date & Time: 2:00-3:00 PM, 16th of July 2014, Wednesday
Venue: Room 361, James Watt South Building 




 Shock wave / boundary layer interactions arising on aeronautical vehicles are prone to unsteadiness with a low frequency of few hundred Hertz, which can induce severe aerodynamic loads. This seminar aims to take a review of current knowledge in the field and give some ideas for future developments. The unsteady dynamics of an oblique shock wave / boundary layer interaction (SWTBLI) on a flat plate is investigated. A numerical tool based both on Large Eddy Simulation and stability analysis is developed for the supersonic regime. Laminar and turbulent SWBLI simulations, linear stability and DMD analyzes are conducted for many configurations in Reynolds and Mach numbers. LES of an unsteady SWTBLI covering dozens of low-frequency cycles is performed. The results suggest that the low-frequency dynamics is related to a global synchronization of the flow, characterized by a cyclic breathing motion of the recirculation bubble, associated with a fore-and aft motion of the reflected shock, together with a modulation of the shear-layer. The study shows that the coupling between the restoring force due to the incident shock and the disturbances generated by the incoming turbulence and the mixing layer is responsible for the low-frequency broadband modulation of the vortex shedding in the downstream flow, corresponding statistically to the low frequency of interest.



First published: 24 October 2013