Results are given of experimental and theoretical studies of "gas-solid particles" turbulent two-phase flows. Special emphasis is placed on studies of the behavior of particles suspended in a turbulent gas flow and their feedback effect on the characteristics of flow of the carrier phase. The characteristics of heterogeneous flows in channels (pipes) are analyzed, as well as those in the vicinity of the critical points of bodies subjected to flow and in the boundary layer developing on their surface. Problems of physical simulation of turbulent gas flows which carry solid particles are treated in detail. This monograph will be useful for researchers involved in investigations of gas dynamics and heat and mass transfer in multiphase flows, as well as for university professors, post-graduate students, and students.