We use singular perturbation theory to analyze weakly compressible multiphase flow for turbulent fluid mixing. Formal asymptotic expansions, uniformly valid in space and time are discussed for the compressible solutions describing the fluid motion as the Mach number goes to zero. We examine transition layers which exist in the intermediate region of the mixing zone edges for the compressible and incompressible flow.

singular perturbation, zero Mach limit, turbulence, multiphase flow.