Abstract
This paper presents some of the aerodynamic interactions between stationary components and the rotating impeller of a centrifugal compressor. This experimental study involved three types of inlet shapes and five types of diffuser configurations fitted to the same radial impeller with stationary shroud. The volute casing and exit duct for the facility also remained unchanged. The investigation included full flow range of these systems using traverses of a three-hole probe and static pressure measurements along the diffuser walls as well as diffuser blade surfaces. The results depict that the inlet duct shape, diffuser type, and shape affect the wall static pressure rise both in vaneless and vaned configurations. The vane surface pressure is grossly affected by the diffuser shape and to some extent by the inlet duct. It is also evident from the study that aerodynamics within the impeller is affected by the geometries of the upstream and downstream components due to the intra-componental aerodynamic interaction among these with the impeller.