Comparison of Conventional and Low Solidity Vaned Diffusers

Abstract

Test results are presented comparing the aerodynamic performance of single stage centrifugal compressors with thin flat plate, low solidity vaned diffusers to conventional thin vaned diffusers. The test data were acquired from a low Mach number process gas compressor and a high Mach number industrial air compressor. The data are all normalized relative to baseline vaneless diffuser results. Performance parameters of stability, head rise to surge, overload flow margin, and stage efficiency are compared. The low solidity vane inlet incidence angle is shown to be an important design parameter that influences both compressor operating range and efficiency.