Breakdown of Counter-Rotating Supersonic Streamwise Vortices Generated by Swept Ramp Injector

Abstract

For supersonic mixing enhancement in scramjet engine, streamwise vortices and its breakdown seem to be the most advantageous. We expect that streamwise vortices break down and develop turbulent mixing field as going the downstream. In order to increase the mixing performance, it is important to introduce streamwise vortices which have larger circulation, and to enhance breakdown of them. In the present study, we examined supersonic mixing field, which is generated by ramp injector which has swept ramp angle, by Schlieren flow visualization, oil flow, and stereoscopic PIV method. It was confirmed that strength of streamwise vortices becomes stronger and they break down rapidly as the swept ramp angle decreases.