Nonisentropic three-dimensional steady and two-dimensional unsteady double waves

The paper gives a complete classification of nonisentropic two-dimensional unsteady and three-dimensional steady gas flows of double-wave type in the case of functional arbitrariness. Pressure and entropy are chosen as the independent variables in the hodograph space. It is shown that, in the three-dimensional steady case, nonisentropic double waves with functional arbitrariness which are not reducible to invariant solutions exist only for gases with an equation of state tau = g(p)A(S). Flows described by these double waves generalize the Prandtl-Meier waves to the three-dimensional nonisentropic case.