Specific features of unsteady exhaustion of a gas-particle mixture into vacuum

Two-dimensional unsteady exhaustion of a one-velocity gas-particle mixture into vacuum is analyzed in extreme equilibrium cases of heat transfer. Domains of existence of a one-dimensional Riemann wave and side expansion wave and the boundary of the expansion region are obtained. In the case of temperature equilibrium, the reverse flow is found to occupy a large region extending beyond the boundaries defined by the angles of expansion of an ideal gas and a gas-particle mixture with thermally insulated phases. Exhaustion of a nonequilibrium two-phase medium in terms of velocities and temperatures into vacuum is numerically simulated. It is demonstrated that a barrel structure with wavy expansion of the gas and combined discontinuities in the expanding gas-particle mixture is formed.