Abstract
We have been working on the supersonic mixing enhancement using streamwise vortices. Experimentally at a freestream Mach number 2.5, this study examines the behaviour of wake shear layer and the small scale, alternately counter-rotating streamwise vortices in spanwise row, which are initially embedded in the shear layer. Another larger scale streamwise vortices are introdueced into the flow to observe their behaviour of interacting with and eventually engulfing these small scale vortices and shear layer. A number of Schlieren photographs show that the embedded vortices highly disturb the shear layer. The near-by large scale vortices are strongly disturbed by engulfing these smaller scale turbulent structures. It is inferred that strong vortical disturbances can develop within the large scale streamwise vortices at their formation when the weak shock waves governing the generation of streamwise vortices undergo oscillations. These results are very useful for the development of supersonic mixing enhancement techniques.
