斜坡型涡流发生器控制叶栅角区分离的数值模拟  

Simulation of corner separation control with ramp vortex generation

作　　者：尚东然 刘艳明[1] 季路成[1] 朱榕 SHANG Dongran;LIU Yanming;JI Lucheng;ZHU Rong(Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]北京理工大学,北京100081

出　　处：《空气动力学学报》2020年第6期1083-1092,I0002,共11页Acta Aerodynamica Sinica

基　　金：国家自然科学基金(51676015)。

摘　　要：压气机平面叶栅端壁附面层的发展以及吸力面-端壁角区流动分离是造成压气机内部流动损失的重要原因。为了最大程度地减弱角区分离,改善叶栅气动性能,采用数值模拟方法对叶栅通道端壁上微尺度斜坡型涡流发生器进行了几何优化,分析了叶栅流场特性,同时进一步研究了涡流发生器对平面叶栅攻角特性的影响。结果表明:涡流发生器产生的流向涡与通道涡及端壁横向流动相互作用使得通道涡和端壁横向二次流发生偏转,抑制了通道涡向吸力面的发展,并将主流高能流体卷入角区,增加了角区流体动量,削弱了角区分离,使得叶栅出口处流场更加顺畅;涡流发生器的几何尺寸直接影响流向涡的强度;通过依次优化涡流发生器的高度和长宽比,最终确定涡流发生器的最优方案为h=4 mm、b=4 mm、l=12 mm,该方案使得出口截面总压损失降低了7.82%;设计攻角下涡流发生器的作用效果最好,随着正负攻角的增加,损失降低程度下降,其中攻角为-8°和8°时,损失较原型分别下降了1.91%和5.29%。The development of end-wall boundary layer in compressor cascade and the corner separation between suction surface and end-wall are the important reasons for the loss of flow in compressor.In order to minimize the corner separation and improve the aerodynamic performance of the cascade,numerical investigation of compressor cascade with micro-ramp vortex generation(VG)placed inside of end-wall has been investigated.The cascade flow field characteristics are analyzed in detail.Furthermore,the influence of vortex generator on the angle of attack of cascade is studied.The results show that,the ramp-VG placed inside of cascade can resist the crosswise flow,and the streamwise vortex generated by ramp VG can interact with the boundary layer in near end-wall region,resulting in limiting the development of passage vortex from pressure to suction side.Meanwhile streamwise vortex entrains high energy fluid to suction side corner region to increase momentum of corner fluid,making the flow field smoother at the outlet of the cascade.Furthermore,the intensity of streamwise vortex is influenced by both height and aspect ratio of the VG.The optimal scheme of the vortex generator is h=4 mm,b=4 mm,l=12 mm.This scheme reduces the total pressure loss at the outlet section by 7.82%.The vortex generator has the best effect under the design point,with the increase of the positive and negative angles of attack,the degree of loss reduction decreases.When the angle of attack is-8°and 8°,the loss is 1.91%and 5.29%lower than the prototype,respectively.

关 键 词：压气机叶栅 微尺度斜坡型涡流发生器 通道涡 角区分离 横向二次流 流场特性 

分 类 号：V231.3[航空宇航科学与技术—航空宇航推进理论与工程]