环形弯扭静叶栅流场的计算与实验研究

本文应用Ｓ２流面正问题计算方法和三维Ｅｕｌｅｒ方程的时间推进计算方法对某涡轮弯扭静叶栅流场分别进行了分析计算，并在环形涡轮叶栅实验台上测试了该叶栅出口截面上气动参数的分布。通过分析、比较计算结果和实验数据，既考核了算法，也研究了弯扭静叶栅中的流动机理，由此得出了对弯扭叶片的气动设计计算具有重要意义的几点结论。

A STUDY ON AN ANNULAR STATIONARY CASCADE WITH BOWED AND TWISTED BLADES

Abstract In this paper,a 3D Euler solver and a direct problem code of S stream surface are applied to numerical analysis of the flow field in an annular stationary turbine cascade with bowed and twisted blades.Also,an experimental study on this cascade is made by blowing on an annular cascade test rig to verify the two calculation programs and to research the flow mechanism in the cascade.Numerical results show that the effect of blade bowing in circumferential direction is mainly reflected in the front of cascade and blade bowing has little influence on the flow beside blade pressure surface.After comparing the calculated results with the experimental data,it is found that in respect of circumferentially averaged flow parameters at the cascade exit,the 3D Euler solver is more precise in predicting the pressure distribution but less precise in predicting the flow angle distribution than the code of S stream surface.The experimental data verify the effect of blade bowing on the flow around blade hub,and show great losses occurring near blade tip due to excessive camber angle of blade profile and improper bowing of blade stacking line in that region.Some difference between the calculated results and the experimental data demonstrates that a more reasonable loss model and a more precise lag angle model should be worked out if a good design for turbine cascade with bowed and twisted blades is expected by means of an Euler solver or a throughflow code.