柔性锯齿形尾缘流动分离控制实验的多尺度相干结构研究  

Experimental study on flow separation control by flexible serrated trailing edge based on multi-scale coherent structure analysis

作　　者：巩绪安 张鑫[3] 马兴宇 范子椰 唐湛棋[1,2] 姜楠 GONG Xu’an;ZHANG Xin;MA Xingyu;FAN Ziye;TANG Zhanqi;JIANG Nan(Department of Mechanics,School of Mechanical Engineering,Tianjin University,Tianjin 300354,China;Tianjin Key Laboratory of Modern Engineering Mechanics,Tianjin 300354,China;State Key Laboratory of Aerodynamics,China Aerodynamics Research and Development Center,Mianyang 621000,China)

机构地区：[1]天津大学机械工程学院力学系,天津300354 [2]天津市现代工程力学重点实验室,天津300354 [3]中国空气动力研究与发展中心空气动力学国家重点实验室,绵阳621000

出　　处：《实验流体力学》2022年第6期19-27,共9页Journal of Experiments in Fluid Mechanics

基　　金：气动噪声控制重点实验室开放课题(ANCL20200105);国家自然科学基金(11902218,11732010,11972251,11872272,11802195);国家重点研发计划(2018YFC0705300)。

摘　　要：本文采用柔性锯齿形尾缘进行了流动分离控制风洞实验。利用高频响热线风速仪测量了翼型尾流场,结合瞬时强度因子迭代算法,在时域、频域提取出多尺度湍流相干结构,分析了弹性振动和柔性形变对扰动传播不稳定性的影响。实验结果表明:尾流中分离区厚度减小5%弦长,柔性锯齿形尾缘跟随来流自适应变形摆动,吸收了约20%的尾缘剪切层中的湍动能,产生的大尺度扰流涡持续传递至前缘剪切层,降低了很大范围低频带宽内的功率谱密度,具有良好的降噪效果;脱落涡中相干结构的振幅和发生频率显著削弱,对尾流分离区边界移动、大型涡包破碎和抑制传播的作用非常明显。This article reports our recent experimental study of airfoil flow separation control by flexible serrated trailing edge.The experiments were conducted in a straight-type wind tunnel and a hot-wire anemometer was used to measure the velocity profile downstream of the two-dimensional airfoil.Multi-scale coherent structures within the separated shear layers are analyzed both in the time and frequency domains.The results show that the separation bubble thickness decreases by almost 5%of the chord length,the flexible serrated trailing edge vibrates and deforms adaptively and absorbs nearly 20%of the trailing edge shear layer’s energy,perturbation transmits to the leading edge shear layer,and thus the power spectral density decreases significantly in the lower and larger bandwidth to reduce the noise.The coherent structures’frequency and amplitude also decrease notably,breaking and inhibiting the large vortex package’s transmission obviously in the separation bubble.

关 键 词：流动分离 柔性材料 锯齿形 小波分析 多尺度相干结构 

分 类 号：O357[理学—流体力学]