Mixed-Flow Compressor Stage Design and Test Results With a Pressure Ratio of 3:1

This paper presents a brief history of mixed-flow compressors, possible applications, and the design and measured performance of a recently tested 3:1 pressure-ratio stage. The stage is intended to run behind a multistage axial compressor; it has an envelope radius only 9.4 percent greater than the rotor tip radius. A tandem cascade diffusing system is used to promote flow range and thus aid matching to the axial stages. Compressor maps from the rig test are presented along with additional data (from static taps and exit rakes) that characterize the behavior of various elements of the stage.