Prediction of Off-Design Performance of Multistage Compressors

Three techniques are presented for estimating compressor off-design performance. The first method,
which is based on blade-element theory, is useful for obtaining only a small part of the compressor
map over which all blade elements in the compressor operate unstalled. The second method, which involves individual stage performance curves and a stage-by-stage calculation, is useful for estimating
the performance of a compressor for which reliable stage performance curves are available. The third
method, which is based on over-all performance data of existing compressors, may be used to estimate the complete performance map of a new compressor if the compressor design conditions are specific.