In applications such as airborne high energy chemical lasers, diffuser size and weight can be critical parameters. This paper summarizes the authors’ research concerning the effects of flow injection into a supersonic diffuser in a direction opposite to that of the main flow. Experimental studies were conducted concerning the effect of diffuser performance, particularly length and pressure recovery, of this reverse flow, and a quasi-one-dimensional control volume analysis was performed to predict some of the diffuser flow properties. Single-stream, dual-stream, and sudden enlargement configurations were considered. This work has shown that a reverse flow can reduce the length of a diffuser while causing only a small decrease in overall pressure recovery.
Casing Treatments on a Supersonic Diffuser for High Pressure Ratio Centrifugal Compressors