This paper describes an improved throughflow calculation method on S2m based on streamline curvature method for predicting the performance of centrifugal compressor. A general method of specifying the empirical data provides separate treatment of blockage, deviation and losses. The spanwise and streamwise distribution laws of losses are described. The paper describes a new aspect of method about the mixing loss. Two-zone model considering the “jet and wake” can obtain the secondary flow width. For this reason, the improved prediction method combined with two-zone model is proposed to correct the mixing loss. Due to the average static pressure at outlet unknown, the secondary flow width is obtained by iterations.
This performance prediction method is validated with experimental and CFD data of three cases, including impeller(A), impeller(B) and impeller(C). The results show that the improved throughflow calculation method predicts the performance of centrifugal compressor more accurately than conventional throughflow calculation, with increased the accuracy of total pressure ratio and isentropic efficiency by about 3.18% and 1.30%.