跨声速叶栅抽吸流、激波以及分离流相干效应

Investigation into effects of interaction among suction flow,shock wave and separation flow for a transonic compressor cascade

关键词:  抽吸流  激波  附面层  相干效应

Key words:  Suction flow  Shock wave  Boundary layer  Interaction effects

摘要:

以某高负荷、跨声速压气机叶栅为研究对象,应用数值模拟手段探讨通过抽吸控制激波从而控制附面层发展的可行方法。研究结果表明:随着抽吸量的增加吸力面马赫数峰值提高,激波损失增加,同时使得吸力面马赫数峰值点位置后移,附面层分离减弱,分离的减弱所导致的总压恢复系数增加量要远大于激波强度增加所导致的总压恢复系数减小量;抽吸对叶栅性能改善存在一个最佳抽吸量1.2%;在保证叶栅静压压升不变的前提下,相对于未抽吸条件1.2%抽吸使得叶栅总压恢复系数提高10%,扩散因子降低18%,落后角减小5°;通道激波后实施附面层小流量抽吸不能有效改善附面层内部流动参数,当实现前缘入射斜激波投射点位于通道激波上游时,叶表附面层流动得到较大改善。

Abstract:

To explore a better control method of separating flow by reconstructing shock waves through boundary layer suction(BLS) technique,a high load transonic compressor cascade with BLS has been studied by numerical simulation.The BLS slot is located downstream of leading edge shock wave impingement point.The results show that with increase of BLS mass flow rate(Cm),the peak of Mach number on suction surface is enhanced and the shock wave moves downstream,which could increase the loss of shock wave while decreases the loss of boundary layer.The amount of improvement for the total pressure recovery coefficient is more than the decreased.For the cascade of this paper,cascade performance is improved with the increasing of Cm,but there is an optimum Cm of 1.2%.Compared 1.2% Cm with 0.0% Cm conditions,1.2% Cm leads to the cascade total pressure recovery coefficient increase of 10%,boundary layer shape factor decrease of 18%,deviation angle decrease of 5 ° while the pressure rise keeps constant.Small Cm can not effectively improve the internal boundary layer flow parameters when the BLS slot rear of shock wave has been implemented.The boundary layer flow is greatly imporved when it is realized by BLS that the impingement point of oblique shock wave original from the cascade leading edge float downstream to the rear of passage shock wave.