Design optimization and analysis of a vaned diffuser based on the one-dimensional impeller-diffuser throat area model

The paper presents a design optimization method for a type of centrifugal compressor's vaned diffuser with using a one-dimensional (1D) mathematical model to determine the best throat area ratio of the impeller to the diffuser. The research aims to verify of the 1D throat area mathematical model and to study the influence of vaned diffuser structure on the impeller-diffuser matching and the stage performance. The results of CFD analysis and experiments have proved that 1D throat area model can predict the throat area ratio of the impeller to the vaned diffuser accurately for the same choking mass flow at the required rotating speed. After optimization, the compressor performances and the matching between impeller and vane diffuser are considerably improved as well. The results and conclusions indicate that quick geometry modification of vaned diffusers can achieve excellent performance optimization and provide the theoretical basis for the selection of variable vaned diffusers.