考虑动叶顶部间隙影响的跨音涡轮级的数值模拟

本文给出了一种基于区域分解算法的可考虑动叶顶部间隙和机匣刮削作用的涡轮级计算方法.并对NASA实验涡轮级进行了计算,计算结果和实验结果吻合得很好.通过分析,可以发现动叶顶部间隙流动将引起动叶顶部气流的欠偏转,从而降低顶部的做功能力,并且这一影响区域会达到一个相当大的范围.在动叶叶片顶部尾缘存在激波的情况下,尾缘激波和顶部泄漏流动相互作用使激波结构变得十分复杂和无序,这种无序的结构必然带来较大的损失.

A Numerical Simulation of Turbine Stage with Tip Clearcance

By using nonoverlapping domain method,a 3 D viscous code had been developed to calculate flow field in a cascade with tip clearance and craping along casing.A turbine stage of NASA is also simulated.The results show that the relative exit flow angle (and axial flow angle) is reduced by leakage flow on top of the rotor.As a result,the flow angle on top is underturned and its loading is reduced.The shock wave structure on top of the rotor becomes very complex and out of order due to interaction between the leakage flow and the shock wave.This out of order shock wave structure will bring high loss.