基于仿生尼龙丝的圆柱绕流被动控制  

Passive control on flow past a circular cylinder with bionic nylon wires

作　　者：陈文礼[1,2,3] 林隆瀚 邓质 高东来[1,2,3] CHEN Wenli;LIN Longhan;DENG Zhi;GAO Donglai(Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education,Harbin Institute of Technology,Harbin 150090,China;Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology,Harbin Institute of Technology,Harbin 150090,China;Lab of Intelligent Civil Infrastructure,Harbin Institute of Technology,Harbin 150090,China)

机构地区：[1]哈尔滨工业大学结构工程灾变与控制教育部重点实验室,哈尔滨150090 [2]哈尔滨工业大学土木工程智能防灾减灾工业和信息化部重点实验室,哈尔滨150090 [3]哈尔滨工业大学智慧基础设施研究中心,哈尔滨150090

出　　处：《实验流体力学》2023年第4期66-75,共10页Journal of Experiments in Fluid Mechanics

基　　金：国家自然科学基金优秀青年科学基金项目(51722805);国家自然科学基金项目(51978222,51578188)。

摘　　要：通过风洞实验研究了鸟类羽毛仿生尼龙丝对圆柱绕流场的控制效果及机理。仿生尼龙丝布置于圆柱的前驻点,雷诺数为2.67×10^(4),特征变量为尼龙丝长度与圆柱直径之比L/D。采用表面压力测量系统获取圆柱表面压力系数以分析圆柱周围的空气动力。利用高速粒子图像测速(PIV)系统获取圆柱的二维流场信息,并将获取的信息进行本征正交分解(POD),得到流场瞬时特性和时均特性。实验结果表明:L/D<0.6时,由尼龙丝诱导产生的旋涡无法到达尾流场,此时尼龙丝的控制效果受到限制;L/D>1.0时,尼龙丝可以显著降低圆柱尾流场的湍动能和雷诺应力,并抑制圆柱的升力系数和阻力系数;当L/D足够大时,尼龙丝可以抑制剪切层之间的相互接触,从而改变圆柱的卡门涡街旋涡脱落模式。We investigated the control effectiveness and mechanism of the control of the circular cylinder flow field using bionic nylon wires inspired by bird feathers by wind tunnel tests.In this experiment,at a Reynolds number of 2.67×10^(4),the bionic nylon filament was arranged at the front station of the cylinder and the length ratio L/D between nylon wire length and cylinder diameter was used as the characteristic parameter.The surface pressure measurement system was used to obtain the pressure coefficients around the cylinder to analyze the aerodynamic forces acting on the cylinder.The two-dimensional flow field information of the cylinder was obtained by a high-speed Particle Image Velocimetry(PIV)measurement system,and the Proper Orthogonal Decomposition(POD)was used to obtain the instantaneous and time-averaged characteristics of the flow field.The results show that at L/D<0.6,the control effectiveness of nylon wires is limited because the nylon-induced vortex structures cannot reach the wake field.At L/D>1.0,the nylon wires can significantly reduce the turbulent kinetic energy and Reynolds stress of the cylindrical wake field and suppress the lift and drag coefficient distributions around the circular cylinder.And at high values,nylon wires can inhibit the interaction between shear layers and thus change the von Kármán vortex shedding pattern of the cylinder.

关 键 词：圆柱尾流 空气动力 仿生 流动控制 尼龙丝 风洞实验 粒子图像测速 本征正交分解 

分 类 号：O351.2[理学—流体力学]