Micro-vortex generators for shock wave/boundary layer interactions

The effect of micro-vortex generators (MVGs) on shock wave/boundary layer interactions (SBLIs) has been reviewed. Experimental and computational evidence has been presented about the dominant role it has in the suppression of shock-induced separation the pair of counter-rotating streamwise vortices, which appears downstream of the types of micro-vortex generators used in SBLIs; these streamwise vortices entrain high momentum fluid, increasing the boundary layer velocity near the wall. The structure of the wake is examined in detail, with emphasis on the strength and decay of the streamwise vortices and on the ring-type or hairpin vortices which have been detected in the instantaneous flow around the wake. Evaluation of the ability of various types of MVGs to suppress shock-induced separation is done. Topics which need to be further studied, like the structure of the flow around devices of small size and the effect of the Reynolds number, are suggested.