涡轮平面叶栅端壁附近的流动和损失

Secondary flow measurements and flow losses near the endwall of linear turbine cascade

关键词:  涡轮  涡轮叶栅  叶栅流  涡流  二次流  流动分布  涡流损耗

Key words:  Turbine  Turbine cascade  Cascade flow  Vortex flow  Secondary flow  Flow distribution  Eddy current loss

摘要:

用五孔针对涡轮导向叶栅流场作了详细测量,着重研究了端壁附近的三维流动,分析了叶栅中的二次流现象和流动损失机理。在实验中清楚地探测到了通道涡和马蹄涡的两个分支。实验发现通道涡主宰了整个二次流流场,马蹄涡吸力面分支在与通道涡的相互作用过程中强度逐渐减弱直至消失。在062Cx截面及其下游截面的吸力面附近,还发现了一个显著的低速高损失核,该核在吸力面上向上爬升并一直延续到叶栅下游。

Abstract:

Measurements of the basic flow fields was made in a turbine cascade with five hole probe Special attentions were given to the three dimensional flow in the near enrdwall region between adjacent blades The relations between secondary flow and loss generation in a cascade were studied The experimental data show that passage vortex dominates the whole secondary flow fields and the two legs of horseshoe vortex are clearly identified But the suction side leg of horseshoe vortex would weaken itself and disappear gradually as the result of interacting with passage vortex On the traversing plane of x=0 62C x and the planes followed, a noticeable low momentum high loss core is found near the suction surface This core climbs upwards on the suction surface till to the far downstream of cascade