Effects of streamwise vortex inducement on growth of a compressible double shear layer are investigated experimentally. Air is injected with a subsonic speed into a co-flowing supersonic air stream in the parallel direction, forming a compressible double shear layer. The Mach numbers of the subsonic and supersonic air streams are 0.29 and 1.78, respectively. The convective Mach number is 0.62. Several types of sine-curved trailing edges are used to induce streamwise vortices into the shear layer. The amplitude, wavelength and phase of the sine curve are varied widely. It is shown that the growth of the streamwise vortices is determined by their spacing. For the symmetric sine-curved trailing edges, the streamwise vortex inducement has no effect on the growth rate of the shear layer. For the asymmetric sine-curved trailing edges, with the increase in the streamwise vortex intensity, the growth rate of the shear layer is increased. At the maximum, 90% enhancement in the mixing is achieved when compared with the straight trailing edge.
