Evolution characteristics of subsonic-supersonic mixing layer impinged by shock waves

Abstract

The study of interaction between shock wave and mixing layer commonly existed in rocket based combined cycle engine is of profound significance for mixing enhancement in combustor. In this paper, the three-dimensional structures of subsonic-supersonic mixing layer impinged by shock waves induced by wedge were investigated experimentally employing the ice-cluster based planar laser scattering technique. The results showed that the mixing layer would partially deflect to the subsonic stream side and inhibit the development of K-H instability vortices under the interaction of induced shock wave. With the increasing of wedge angle (β), the interaction of shock waves could enlarge the global deflection angle of mixing layer and reduce the scale of large-scale vortices. Moreover, the T-shaped structures and horseshoe vortices were existed as usual topological structures in small-scale turbulent transport. Besides, the curved shock waves were generated under the influence of large-scale vortices. In addition, the comparison of mixing layer thickness indicated that the evolution of mixing layer could be promoted for β=5°, while it would be suppressed for β=15° in general.