Centrifugal compressor with aerodynamically variable geometry diffuser

摘要

A centrifugal compressor (11) has a diffuser (28) with fixed vane geometry which provides a significantly increased operating range, as compared to conventional fixed geometry diffusers, by developing what appear to be flow-accelerating stall bubbles (46) in a throat of the diffuser (28) that forestall the onset of surge in the portion of the operating range near and approaching the surge point. The stall bubbles (46) are created by fixing the suction sides (40) of the vanes (31), relative to the flow impinging upon their leading edges, at angles slightly more radially inclined than is conventional, thereby creating higher than normal angles of incidence with the flow delivered by the impeller (18) of the compressor (11).