Incidence Angle Adaptability Investigation of Non-Axisymmetric Endwall Contouring on Turbine Loss Control
The non-axisymmetric endwall technology can effectively reduce the aerodynamic loss caused by circumferential secondary flow and improve the turbine efficiency.In order to evaluate the effect of endwall contouring in the turbine cascade under different incidence angles,the shroud of the stator cascade of a high-pressure turbine is taken as the object of study.The contouring and optimization of the non-axisymmetric endwall was carried out with the total pressure loss of the turbine outlet as the optimization objective under the condition of 0° incidence angle,and the study obtained a kind of contoured endwall which is able to effectively reduce the secondary kinetic energy and the aerodynamic loss of the cascade.The loss control effect of this endwall was analyzed under the condition of varying incidence angles.The results show that the non-axisymmetric endwall contouring used in this study can effectively reduce the aerodynamic loss of the cascade in the range of incidence angles investigated,and the effect of the contouring on several major secondary flow structures does not change much in these conditions;in the negative incidence angle conditions where the secondary flow strength is weaker than in other incidence angle conditions,the contouring has a more significant effect on the horseshoe vortex structure.