Zhang Botao, Liu Bo, Han Changfu, Zhao Hang
School of Power and Energy, Northwestern Polytechnical University, Xi'an 710129, China.
Entropy (Basel). 2020 Jan 21;22(2):128. doi: 10.3390/e22020128.
To investigate the influence of the change of tip clearance size on the control effect of the endwall suction, the effects of endwall suction on the aerodynamic performance of the axial compressor cascade were studied numerically. Three tip clearance sizes of 0.5% h, 1.0% h, and 2.0% h (h is the blade height) were mainly considered. The results show that the endwall suction scheme whose coverage range was 8-33% axial chord can reduce the leakage flow and improve the aerodynamic performance by directly influencing the structure of tip leakage vortex. The overall total pressure loss coefficients of the three clearance size schemes at 0° angle of incidence with 0.4 inlet Mach number are reduced by about 10.3%, 10.8%, and 6.0%, respectively, at the suction flow rate of 0.7%. Under the same suction flow rate, the onset position of the tip leakage vortex of the cascade with small clearance is shifted from the 15% of the axial chord length of original to the 48% of the axial chord length, which with large clearance is nearly no changed. The leakage flow rate and the distance from the leakage vortex to the suction slot are the main reasons for the different control effect of the endwall suction under different tip clearance sizes. The difference of the spanwise distribution of flow field parameters may also cause the difference of flow control effect.
为了研究叶顶间隙尺寸变化对端壁抽吸控制效果的影响，对端壁抽吸对轴流压气机叶栅气动性能的影响进行了数值研究。主要考虑了0.5%h、1.0%h和2.0%h（h为叶片高度）三种叶顶间隙尺寸。结果表明，覆盖范围为轴向弦长8%-33%的端壁抽吸方案可通过直接影响叶顶泄漏涡的结构来减少泄漏流并改善气动性能。在进口马赫数为0.4、攻角为0°时，三种间隙尺寸方案在抽吸流量为0.7%时的总压损失系数分别降低了约10.3%、10.8%和6.0%。在相同抽吸流量下，小间隙叶栅的叶顶泄漏涡起始位置从原来轴向弦长的15%处移至轴向弦长的48%处，而大间隙叶栅的起始位置几乎不变。泄漏流量以及泄漏涡到抽吸缝的距离是不同叶顶间隙尺寸下端壁抽吸控制效果不同的主要原因。流场参数展向分布的差异也可能导致流动控制效果的差异。
