某高压涡轮时序效应的数值仿真研究

Numerical Simulation Investigation of Airfoil Clocking in a High-pressure Turbine

研究提高涡轮机性能问题,如何提高叶轮机械气动效率一直是人们普遍关心的问题,将研究时序效应技术用于提高涡轮气动性能。采用商业软件CFX11.0进行数值仿真,在一个栅距内改变第二级静叶相对第一级静叶的周向位置,结果发现涡轮效率也随之发生改变,分析涡轮非定常时均流场发现,不同的时序位置,第一级静叶出口流场几乎没有变化,时序效应主要影响第二级静叶出口流场,在叶尖和轮毂区,最小效率和最大效率时序位置均表现出较高的损失,然而沿第二级静叶径向,对应最小效率时序位置栅距平均的总压损失系数明显要高,通过数值仿真,结果表明,可以找到最优叶片排列方式,改进涡轮性能和提高涡轮效率。

People always try to find some effective ways to improve the turbo machinery＇s aerodynamic efficiency,In this paper,a numerical investigation was conducted about the clocking effect on a high pressure turbine using the CFD software CFX11.0.By varying the circumferential position of the first stage vane corresponding to the second stage vane in a pitch,found that the efficiency changed correspondingly.Analyzing the unsteady time-averaged flow filed,showed that different clocking position had nearly no effect on the exit flow filed of the first stage vane,while the clocking position mainly affected the exit flow filed of the second stage stator in the tip and hub region,both the maximum and minimum efficiency clocking position presented higher loss,but along the radial direction,the pitch-averaged total pressure loss coefficient corresponding to the minimum efficiency clocking position was significantly higher,which proved that airfoil clocking can be used to improve the turbine performance.