Abstract: A new method is proposed for extrapolating characteristic maps of multistage axial flow compressors based on an introduction of infinitesimal stage. With comparison from conventional Reynolds extrapolation method, the proposed method divides air-polytropic process into infinitesimal stage. Consequently, the condition required by Reynolds analogy (RA) is satisfied perfectly for the infinitesimal stage’s approximation to RA premises. With this idea the entire characteristic map of compressor can be reconstructed by the combination of infinite-stage characteristic maps. Validation efforts show the discussed method has higher precision and fewer errors to simulate compressor operating process. This work contributes to the improvement of calculation characteristic maps of axial flow compressors.

Key words: Axial flow compressors, Characteristic maps, Similarity extrapolation, Thermodynamic system