间隙大小对压气机转子间隙泄漏流场的影响

针对叶尖率先出现失速信号的一亚音速轴流压气机转子,采用全三维数值模拟方法分析了3种顶部间隙情况下泄漏流动特点,以及它对转子气动性能的影响。数值模拟结果表明,不同间隙情况下泄漏涡的运行特性与压气机的性能和稳定性密切相关。3种间隙情况下,泄漏涡在近失速工况下均发生了破碎。涡破碎造成泄漏涡体积突然膨胀,从而使堆积在机匣壁上的低能流体迅速扩散,对来流产生了很大的阻塞效应。在下游工况相同的条件下,大间隙时最先发生了泄漏涡破碎,说明泄漏涡初始形成时的强度越强,越容易出现涡破碎。

Effects of Tip Clearance Size on Tip Leakage Flow Fields in a Subsonic Compressor Rotor

This paper aims at the numerical analysis of the influence of tip clearance size on aerodynamics in a subsonic tip critical compressor rotor.We make use of well known methods of numerical analysis,including NUMECA Fine / Turbo module,to obtain tip clearance flow fields,which are shown in Figs.3 through 7 in the full paper.We analyze these figures to identify the effects of the tip clearance size on the behavior of tip leakage vortex,which is closely related to the performance characteristic of the rotor.We find that tip leakage vortex breaks down in all investigated cases.The vortex "breakdown" causes a sudden growth of the casing-wall boundary layer,which has a large blockage effect on incoming flow.Under the same downstream conditions,the vortex breakdown occurs earliest in the case of the largest tip clearance size.This verifies that the strength of leakage vortex is one of the major factors influencing the vortex breakdown.