Theory of hybrid contact discontinuities

A new form of discontinuity for low Mach number compressible Bow of an ideal gas in a channel is described. This ''hybrid contact discontinuity'' exhibits the expected jumps in temperature and density, but, surprisingly, also develops a discontinuity in the fluid velocity across the moving contact surface. In contrast to the standard contact discontinuity, the velocity of the contact surface is not equal to, but much slower than the gas velocity. The hybrid contact discontinuity results from the thermal interaction between the gas and the channel wall. This interaction can also stabilize the contact surface.