ABSTRACT
If the pressure ratio of a single-stage centrifugal compressor is larger than four, the velocity relative to the inducer and also to the diffuser usually exceeds the velocity of sound. That is, generation of shock is expected. Since a conventional vaned diffuser is sensitive to the angle of incidence especially at supersonic conditions, the flow range of a high-pressure-ratio compressor with a vaned diffuser is very narrow. Therefore the supersonic centrifugal compressor is hardly used for industrial applications. Once the operating range is broadened, the applicable field of transonic centrifugal compressors, such as for small-size gas turbines and for large-capacity refrigeration systems, should increase.
