Abstract: A method and apparatus for injecting a secondary supersonic stream into a primary supersonic stream. A secondary flow nozzle is designed to contain non-uniformities so as to produce stream-wise vortices. The primary supersonic flow is allowed to flow over a ramp surrounding the secondary nozzle. At the aft end of the ramp, stream-wise vortices appear in the primary flow rotating in the same direction as the vortices in the secondary stream. As a consequence, the vortex strength is increased, leading to enhanced entrainment in mixing of the two streams.

Abstract: A flow plate positioned upstream of the lasing cavity of an electrically pulsed gas laser blocks the transmission of shock waves generated in the laser cavity. The flow plate has a plurality of passages which are shaped to form a supersonic nozzle at the upstream end of the passage, a subsonic diffuser at the downstream end of the passage and a supersonic diffuser in the central region of the passage.