An Efficient and Robust Rotor-Stator Interfacing Method Capable of Handling Reverse Flows and Variable Specific Heat Within Multistage Turbomachines

Abstract

Abstract This paper presents the study of an efficient, robust, conservative, and nonreflective rotor-stator interfacing method for aerodynamic analysis of multirow turbomachines. This rotor-stator interfacing method computes flow variable differences by flux differences based on a control volume concept. It is found that this method is robust and can handle flow reversals. So far, the application of this method is restricted to analyzing flow fields with constant specific heat and its application to variable specific heat has not been reported in the open literature. This work will extend this rotor-stator interfacing method from constant to variable specific heat. To showcase its advantage over Holmes’ and flow-based methods, two multirow test cases, i.e. the NASA Stage 35 and the E3 high-pressure turbine, are adopted. The turbine case necessitates the use of variable specific heat due to the big temperature variation in the flow field. The results show that this novel method is more stable than Holmes’ method, especially for reverse-flow cases. Compared with the flow-based method, the novel method, as one type of flux-based mixing plane method, can well guarantee flux conservation. Furthermore, this novel method presents a unified approach for both constant and variable specific heats. It is more efficient and easier to implement in a flow solver than Holmes’ method since there is no need to use the Newton-Raphson method to compute mixed-out flow variables from circumferential area-averaged flux for variable specific heat.