New Profile Loss Model for Improved Prediction of Transonic Axial Flow Compressor Performance in Choking Region

Abstract

New off-design profile loss models have been developed by performing thorough investigations on compressor performance prediction using one-dimensional stage-stacking approach and three-dimensional computational flow dynamics (CFD) results. Generally, a loss model incorporating various compressor geometry and operating conditions is required to predict the performance of various types of compressors. In this study, three sets of selected loss models were applied to predict axial flow compressor performance using stage-stacking approach. The results were compared with experimental data as well as CFD results. The comparison shows an interesting observation in choking region where the existing loss models cannot capture the rapid decrease in pressure and efficiency while CFD predicted the characteristics. Therefore, an improved off-design profile loss model is proposed for better compressor performance prediction in choking region. The improved model was derived from the correlation between the normalized total loss and the incidence angle. The choking incidence angle, which is a major factor in determining the off-design profile loss, was derived from correlations between the inlet Mach number, throat width-to-inlet spacing ratio, and minimum loss incidence angle. The revised stage-stacking program employing new profile loss model together with a set of loss models was applied to predict a single and multistage compressors for comparison. The results confirmed that the new profile loss model can be widely used for predicting the performance of single and multistage compressor.