Abstract
Linear instability waves in supersonic shear layers are analyzed. Both viscous and inviscid disturbances are considered. The basic state is obtained by solving the compressible laminar boundary‐layer equations or is specified by the hyperbolic tangent profile. The effects of the velocity ratio and temperature ratio are determined. The numerical results show that the maximum growth rate depends nonlinearly on the velocity ratio. The results also substantiate the convective Mach number as a compressibility parameter for mixing layers.