Effects of a curved trailing edge on growth of a compressible “single” shear layer are investigated experimentally. The results are directly compared with those for a compressible “double” shear layer. Mach numbers of the high speed and low speed air streams are 1.78 and 0.29, 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 wavelength of the sine curve is varied widely. It is shown that spanwise vortices due to the primary instability are much more obscure and the spacing varies widely, when compared with those for the compressible double shear layer. And it is shown that, by use of the curved trailing edge, streamwise vortices are induced into the flow. By use of the curved trailing edge, the growth rate of the compressible single shear layer slightly increases. However, when compared with the compressible double shear layer, the increase in the growth rate is much smaller. It is shown that the curved trailing edge is effective for mixing enhancement only when it is used for a compressible double shear layer.
View full abstract