冲角对涡轮低压导向器气动特性影响的实验研究

本文实验研究了通过前置可调导叶改变来流气流方向对涡轮低压导向器环形叶栅损失的产生与分布的影响, 以及在沿叶高不同分布的冲角下模型叶栅气动特性的变化。在不同的沿叶高分布的进气冲角下, 详细地测量了导向器出口流场和叶栅表面静压分布, 得出导向器总流动损失随平均冲角的变化, 从而确定了对应最小流动损失的冲角范围, 对导向器的变工况性能做出了评价。 

Experimental Investigation on Influence of Incidence on Performance of Turbine Stator Cascade

An experimental investigation was carried out to examine the influence of incidence angle on the performance of an annular turbine stator cascade with controlled outlet angle guide vanes.The tests were made at seven incidence angles from +25° to -28°.The five hole probe measurements were performed at two planes,one was located at the stator cascade exit and another at the guide vane exit.The static pressure distribution on the stator blade surface was also measured.The distributions of local energy loss coefficients with local static pressure coefficients,as well as the secondary flow velocity vector plots show in detail,how much the losses and the secondary flow are influenced by incidence angles.At positive incidence,the losses rise mainly due to the development of passage vortex.At negative incidence,the losses rise due to the separation of pressure surface boundary layer.