We found the energetic stability criteria of non-equilibrium gase plain flows.

The classical problem of the fluid mechanics is the problem of a supersonic motion around a thin body was generalized to the case of non-equilibrium gas. The drag and lift force coefficients were founded. It is shown that the drag and lift force coefficients in the acoustically active supersonic flow are both decreased.

We found the energetic stability criteria of non-equilibrium gase plain flows. The second (volume) viscosity coefficient ζ can be negative in nonequilibrium media. Medium with the negative second viscosity is acoustically unstable. The nonlinear structures in the acoustically active gases is strongly different from that in the equilib-rium media. In present paper we investigate some problems, connected with the second viscosity influence on flow characteristics.

It’s considered some effects of the gas‐plasma interaction that is discharge damping behind the shock wave front, the structure of the weak shock wave (SW) front in plasma and SW generation by the breakdown wave front.