Unsteady three-dimensional flow phenomena due to breakdown of tip leakage vortex in a transonic axial compressor rotor
Unsteady three-dimensional flow phenomena due to breakdown of tip leakage vortex in a transonic axial compressor rotor
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DOI：
10.1115/gt2004-53745
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
Kazutoyo Yamada;M. Furukawa;T. Nakano;M. Inoue;K. Funazaki
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文献类型：
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作者：
Kazutoyo Yamada;M. Furukawa;T. Nakano;M. Inoue;K. Funazaki
通过非定常雷诺平均纳维-斯托克斯模拟研究了跨音速轴流压缩机转子（NASA Rotor 37）中的非定常三维流场。仿真结果表明，由于涡流与激波的相互作用，压气机转子发生叶尖泄漏涡流的破坏。在接近峰值效率的情况下，尖端泄漏涡流的小气泡型破裂会周期性地发生，并导致相邻叶片的载荷在前缘附近周期性地波动。由于前缘附近的叶片载荷与叶尖泄漏涡的旋流强度密切相关，叶片载荷的周期性波动会导致叶尖泄漏涡的周期性击穿，从而导致叶尖泄漏流场产生自持流动振荡。然而，尖端泄漏涡流破坏非常弱且小，以至于在接近峰值效率条件下的时间平均流场中没有观察到它。另一方面，叶尖泄漏涡的螺旋型破坏是由近失速工况下涡与冲击波之间的相互作用引起的。由于叶尖泄漏涡流的旋流强度在近失速状态下保持较强，因此连续发现涡流破裂。螺旋型涡流破裂具有自持流动振荡的性质，导致叶尖泄漏流场在激波位置、转子叶尖附近的堵塞以及吸力面的三维分离结构等方面产生较大的波动。研究发现，叶尖泄漏涡的破坏会导致转子叶尖附近出现非定常流动现象，并伴随着跨音速压气机转子在近失速状态下的大堵塞效应。Copyright © 2004 by ASME
Unsteady three-dimensional flow fields in a transonic axial compressor rotor (NASA Rotor 37) have been investigated by unsteady Reynolds-averaged Navier-Stokes simulations. The simulations show that the breakdown of the tip leakage vortex occurs in the compressor rotor because of the interaction of the vortex with the shock wave. At near-peak efficiency condition small bubble-type breakdown of the tip leakage vortex happens periodically and causes the loading of the adjacent blade to fluctuate periodically near the leading edge. Since the blade loading near the leading edge is closely linked to the swirl intensity of the tip leakage vortex, the periodic fluctuation of the blade loading leads to the periodic breakdown of the tip leakage vortex, resulting in self-sustained flow oscillation in the tip leakage flow field. However, the tip leakage vortex breakdown is so weak and small that it is not observed in the time-averaged flow field at near-peak efficiency condition. On the other hand, spiral-type breakdown of the tip leakage vortex is caused by the interaction between the vortex and the shock wave at near-stall operating condition. The vortex breakdown is found continuously since the swirl intensity of tip leakage vortex keeps strong at near-stall condition. The spiral-type vortex breakdown has the nature of self-sustained flow oscillation and gives rise to the large fluctuation of the tip leakage flow field, in terms of shock wave location, blockage near the rotor tip and three-dimensional separation structure on the suction surface. It is found that the breakdown of the tip leakage vortex leads to the unsteady flow phenomena near the rotor tip, accompanying large blockage effect in the transonic compressor rotor at the near-stall condition.Copyright © 2004 by ASME