Hybrid numerical approach for extraction camber curve of turbine blades
                                                     FANG Zhi yang, LUO Tian shu, XU Shao jie, FANG yin
                                                 (Hangzhou Steam Turbine Co., Ltd., Hangzhou 310022, China)

Abstract: Aiming at the problem that the inscribed circles of leading edges and trail edges of turbine blades are difficult to obtain in solving the mean camber curve of two dimensional profiles of turbine blades, several algorithms were investigated. A hybrid approach was proposed to solve inscribed circles of 2D profiles. The approach is that standard optimization methods were applied to search inscribed circles fitting leading edges or trail edges, traditional approaches were employed to calculate inscribed circles of other regions of a blade profile. A software employing the hybrid approach was utilized to investigate NACA65 series compressor blades and blades of a gas turbine. The results indicate that the mean line and thickness distribution calculated by this approach is slightly different from original classical data; The results demonstrates good stability in solving inscribed circles of leading edges and trailing edges, but there are no differences at other regions.

Key words: camber curve; turbine blade profile; nonlinear optimization