Losses in Vaneless Diffusers of Centrifugal Compressors and Pumps: Analysis, Experiment, and Design

Two simple analyses are developed to predict losses in centrifugal compressor (or pump) vaneless diffusers: (a) One-dimensional, axisymmetric friction loss and (b) sudden-expansion mixing to account for losses in the diffuser caused by wakes of separated impeller blades. It is shown that these theories may be substituted for the more complex theory of Dean and Senoo [5]. Some experimental data are included to show the validity of the friction-loss analysis. Finally, the utility of the analyses in design is demonstrated.