On Supersonic Flow of a Two-Dimensional Jet in Uniform Stream

Abstract

It is well known that a supersonic gas jet issuing from a reservoir into a medium at rest has a periodic structure if the difference of pressure of the jet from the medium is not large. This paper investigates a similar situation when a supersonic gas jet is issuing into a uniform stream. I t is found that if the uniform stream is subsonic, the supersonic jet has almost periodic structure, and the approximate wave length increases with the Mach Number of the surrounding stream for a given Mach Number of the jet. If the uniform stream is supersonic, the supersonic jet does not have periodic structure. The transmission and the reflection of small disturbance at the boundary of the jet—i.e., a vortex sheet—are investigated. Factors of transmission and reflection of disturbances on the vortex sheet are found. They are functions of the Mach Numbers of the jet and that of uniform stream. The reflection wave may be of the same sign or of opposite sign of the incident wave or zero according to the Mach Numbers of the two streams.