Oblique-shock/turbulent-boundary-layer interaction
OOblique-shock/turbulent-boundary-layer interaction
E. Touber N. D. Sandham Department of Aeronautics, Imperial College London,South Kensington Campus, London SW7 2AZ, U.K. School of Engineering Sciences, University of Southampton,University Road, Southampton SO17 1BJ, U.K.
Abstract
The present numerical investigation uses well-resolved large-eddysimulations to study the low-frequency unsteady motions observed inshock-wave/turbulent-boundary-layer interactions. Details about thenumerical aspects of the simulations and the subsequent data analysiscan be found in three papers by the authors (Theo. Comput. FluidDyn., 23:79–107 (2009); Shock Waves, 19(6):469–478 (2009) and J. ofFluid Mech. (2011)). The fluid dynamics video illustrates the com-plexity of the interaction between a Mach 2.3 supersonic turbulentboundary layer and an oblique shock wave generated by a 8-degreewedge angle. The first part of the video highlights the propagation ofdisturbances along the reflected shock due to the direct perturbation ofthe shock foot by turbulence structures from the upstream boundarylayer. The second part of the video describes the observed block-likeback-and-forth motions of the reflected shock, focusing on timescalesabout two orders of magnitude longer than the ones shown in thefirst part of video. This gives a visual impression of the broadbandand energetically-significant peak in the wall-pressure spectrum at lowfrequencies. The background blue-white colouring represents the tem-perature field (with white corresponding to hot) and one can clearlyappreciate why such low-frequency shock motions can lead to reducedfatigue lifetimes and is detrimental to aeronautical applications. a r X i v : . [ phy s i c s . f l u - dyn ] O c tt