Stator re-stagger optimization in multistage axial compressor

As a widely applied technique in multistage axial compressors, variable stator vanes (VSV) can flexibly rematch the blade rows to fulfil a variety of aerodynamic performance requirements, such as high efficiency and wide surge margin. The purpose of this paper is to develop an optimization method to quickly determine VSV settings during the preliminary design phase. A mean-line method with a model calibration procedure is adopted to evaluate compressor performance, and the NSGA-II algorithm is employed for automatic optimization. The developed optimization system is then employed to determined re-stagger arrangement in a multistage compressor. A single-speed optimization with performance constraints of specific operating point and a multi-speed optimization with different control laws are conducted. Results are compared with available experimental re-stagger scheme, which verifies the effectiveness of the restagger optimization method. Moreover, method is proposed to determine operating parameters of a working point with a user-defined pressure ratio or mass flow rate after variable geometry.