Note on instability of compressible jets and wakes to long-wave disturbances

Abstract

A two-dimensional jet or wake is observed in a frame of reference moving with the fluid at infinity, so that the velocity w(y) in the x-direction tends to zero as y → ± ∞. The fluid is assumed to be an inviscid perfect gas, to undergo-adiabatic changes, and the local speed of sound to be a function of y such that a(y)→ a∞, as y → ±∞. If the disturbance pressure has the form