Effects of Tip Leakage Vortex Breakdown on Flow Field in Turbomachinery Blade Row

叶尖泄漏涡击穿对透平机械叶排流场的影响

基本信息

批准号：
10650181
负责人：
FURUKAWA Masato
金额：
$ 2.18万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10650181/
关键词：
Turbomachinery Blade Row Tip Leakage Vortex Vortex Breakdown Compressor Blade Tip Flow

项目摘要

The tip leakage vertex rolled up near the leading edge takes on the spiral-type breakdown in the fore part of the rotor passage at the near-stall conditions. The onset of the leakage vortex breakdown causes the drastic changes in the nature of the leakage vortex: downstream of the breakdown onset, the leakage vortex twists and turns violently with time, and has no feature of the streamwise slender vortex. The large movement of the leakage vortex gives rise to a strong interaction of the leakage vortex with the pressure surface of the adjacent blade. Although the interaction causes no separation of the blade boundary layer, the effects of the leakage vortex breakdown play a major role in the unsteady flow nature near the rotor tip at the near-stall conditions.The spiral-type breakdown of the tip leakage vortex brings about the anomalous flow phenomena in the leakage flow field at the near-stall conditions: no rolling-up of the leakage vortex downstream of the rotor, disappearance of the casing wall pressure trough corresponding to the leakage vortex, large spread of the low-energy fluid accumulating on the pressure side, and large pressure fluctuation on the pressure side.As the low rate is decreased further from the near-stall conditions, the movement of the tip leakage vortex due to its breakdown becomes so larger that the leakage vortex interacts with the suction surface as well as the pressure one. The interaction gives rise to the three-dimensional separation of the suction surface boundary layer near the tip. As a result, the total pressure rise across the rotor decreases drastically. It is found that the stall in the compressor rotor can be caused by the effect of the leakage vortex breakdown.

尖端泄漏的顶点在前缘附近滚动，在近阶条件下，转子通道前部的螺旋型崩溃。泄漏涡流的开始引起了泄漏涡流的性质的巨大变化：崩溃开始的下游，泄漏涡流的曲折，随着时间的流逝而剧烈变化，并且没有流质细长的涡流。泄漏涡流的较大运动导致泄漏涡流与相邻刀片的压力表面的强烈相互作用。尽管这种相互作用不会导致叶片边界层的分离，但泄漏涡流崩溃的效果在近台阶的转子尖端附近的不稳定流动性质中起主要作用。尖端泄漏涡流的螺旋型泄漏涡流的螺旋型损坏使近距离漏水的漏水范围的泄漏量的泄漏量的泄漏量的泄漏范围的泄漏量的异常流动现象：壁压槽对应于泄漏涡流，压力侧积聚的低能流体的大扩散以及压力侧的大压力波动。由于低速速率与近阶条件相比，由于其损坏而导致的尖端泄漏涡流的移动更大，以至于泄漏涡流变得更大，以至于泄漏涡流与渗水表面相互作用。相互作用引起了吸入表面边界层附近的三维分离。结果，整个转子的总压升高大大降低。发现压缩机转子中的摊位可能是由泄漏涡流分解的效果引起的。