Flowfield and Performance Measurements in a Vaned Radial Diffuser

The flow characteristics of a vaned diffuser typical of those currently used in centrifugal compressors have been determined experimentally by using a static diffuser test rig. The vortex test vehicle (VTV) portion of this rig was used to simulate the essential features of the flow leaving the impeller of an actual compressor. The mean flow phenomena at the diffuser entrance and the static pressure recovery along the diffuser passage have been determined. In addition, the flow angle and Mach number distributions at several key locations throughout the diffuser channel have been obtained. The most notable feature of the diffuser flowfield is the high degree of nonuniformity in the inlet/leading edge region.