In most turbomachinery design systems streamline curvature based throughflow calculations makes the backbone of aero design process. The fast, reliable and easy to understand solution is especially useful in performing several multistage design iterations in a short period of time. Although the streamline curvature based technique enjoys many benefits for subsonic applications there are some challenges for transonic and supersonic flow applications, which is the focus of this paper In this work it is concluded that three key improvements are required to handle transonic flows in a streamline curvature throughflow solver. These are: 1) ability to overcome dual sub-and supersonic solution and guide the solver towards supersonic flow solution where applicable; 2) suitable technique to calculate the streamline curvature gradient term which can avoid singularity at sonic meridional Mach number and high gradient values in transonic flows; 3) suitable technique to handle choked flow in the turbomachinery flowpath. Solution procedures for "dual-solution" and choked flow treatment are new and developed as part of this work. However, procedure for calculating streamline curvature gradient is leveraged from earlier work done by Denton [ 1 ] and Came [2]. Implementation of these improvements is performed in a streamline curvature based throughflow solver. Numerical improvements presented here have been tested for a range of compressor and turbine cases (both subsonic and supersonic). It is shown that the numerical improvements presented in this paper resulted in an enhanced version of streamline curvature throughflow solver. The new code produces consistent solution for subsonic applications with no sacrifice in accuracy of the solver. However, considerable robustness improvements are achieved for transonic turbine cases.
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