Computer program for predicting off-design performance of centrifugal compressors

A FORTRAN program for calculating the off-design performance of centrifugal compressors with channel diffusers is presented. Use of the program requires complete knowledge of the overall impeller and diffuser geometries. Individual losses are computed using analytical equations and empirical correlations which relate loss levels to velocity diagram characteristics and overall geometry. On a given speed line compressor performance is calculated for a range of inlet velocity levels. At flow rates between surge and choke, individual efficiency decrements, compressor overall efficiency, and compressor total pressure ratio are tabulated. An example case of performance comparison with a compressor built by a commercial engine manufacturer is presented to demonstrate the correlation with limited experimental data.