基于粘性伴随方法的涡轮叶片二次流损失优化设计

Optimization Design of a Turbine Blade to Reduce Secondary Flow Loss Using a Viscous Adjoint Method

在航空涡轮叶片设计中,减少流动损失对改善涡轮叶片性能具有十分重要的意义。本文介绍了一种连续伴随方法在涡轮叶片优化设计中的应用,通过对某低展弦比涡轮叶片的根壁外形进行优化来减少二次流损失。首先通过改变叶高方向的安装角分布使得气流出口偏转角逼近目标分布,以此验证粘性伴随方法的精确性和有效性。其次,在优化二次流损失时,设计目标选取为叶片通道出口的熵增,同时满足出口流动偏转角约束。最后,分析讨论了叶片根壁外形变化对减小二次流损失及二次动能的影响。结果表明:该优化设计能有效地减小二次动能,从而提高叶片的效率。

Reduction of flow loss in turbo-machinery is significant for improving the performance of turbine blades in design of aviation turbine blade.In this paper,the application of a continuous viscous adjoint equation method to the aerodynamic design optimization of a low aspect-ratio turbine blade to reduce the secondary flow loss through endwall profiles contouring is presented.Firstly,an inverse design case is performed to achieve a given flow turning distribution at the outlet through re-staggering the blade along span,through which the efficiency and the feasibility of the viscous adjoint method are verified.Then,in the design of secondary flow loss reduction,entropy production at the outlet of the blade passage is selected as the design objective with a constraint to keep the flow turning.Finally,the effects on the reduction of secondary flow loss and secondary kinetic energy due to endwall profiles contouring are presented and analyzed.The results demonstrate that the optimization design presented in this paper can effectively reduce the secondary kinetic energy and consequently increases the efficiency of the turbine blade..