端壁非定常脉冲射流对高速扩压叶栅性能的影响

Effects of Unsteady End-Wall Pulsed Jets on Performance of High Speed Compressor Cascade

关键词:  压气机  叶栅  脉冲射流  气动性能  流动控制  数值模拟

Key words:  Compressor  Cascade  Pulsed jets  Aerodynamic performance  Flow control  Numerical simulation

摘要:

为探究非定常脉冲振荡射流对高速平面扩压叶栅气动性能、分离流动控制以及流场结构的影响，基于CFX数值模拟方法对平面扩压叶栅进行端壁非定常脉冲射流研究，分析射流效果随射流位置、角度和强度的变化规律。结果表明，通过角区脉冲射流可以显著提高叶栅气动性能，仅采用不足叶栅主流0.3%的射流流量，就能使叶栅出口总压损失系数降低28.66%。当射流位于吸力面侧分离起始位置稍下游时控制效果最佳；射流角度、射流强度和射流频率的最佳值分别为α=20°，C_u=110%和F⁺=0.80；脉冲射流具有较好的适应性，在来流冲角i=-8°~+4°内均能降低叶栅损失。脉冲射流主要通过抑制和推迟通道涡和集中脱落涡的发展，减小其影响范围来改善叶栅内的涡系结构。

Abstract:

To explore the effects of unsteady pulsed jets on aerodynamic performance， separation flow control and flow field structure of a high speed liner compressor cascades， based on CFX numerical simulation， the end-wall unsteady pulsed jet of line compressor cascade was studied， and the effects of jet locations， angle and intensity were analyzed. The results show that the aerodynamic performance of cascade can be significantly improved by corner pulsed jets. With a tiny jet-to-mainstream mass flow ratio of 0.3%， a maximum total pressure loss coefficient reduction of 25.80% relative to the baseline is obtained. The optimal jet location is slightly downstream position of the suction separation line. The optimal values of jet angle ， intensity and frequency are α=20°， C_u=110% and F⁺=0.80， respectively. The pulsed jet has good adaptability and can reduce cascade loss in the range of incoming flow angle i=-8°~+4°. Pulsed jet can improve the vortex structure in cascade mainly by suppressing and delaying the development of passage vortex and concentrated shedding vortex and reducing their influence range.