脉动流条件下的圆柱绕流特性研究  

Investigation on Flow Characteristic of Flowing around a Circular Cylinder under the Pulsating Flow Condition

作　　者：曹兴[1] 刘宇飞 于恒 孔祥鑫 李庆领[1] CAO Xing;LIU Yu-fei;YU Heng;KONG Xiang-xin;LI Qing-ling(College of Electromechanical Engineering,Qingdao University of Science and Technology,Qingdao 266061,China)

机构地区：[1]青岛科技大学机电工程学院,青岛266061

出　　处：《科学技术与工程》2020年第15期5926-5931,共6页Science Technology and Engineering

基　　金：山东省自然科学基金(ZR2018PEE017);青岛市应用基础研究计划(17-1-1-17-jch)。

摘　　要：为探究脉动流对流体绕流结构物产生的影响,采用数值方法研究了脉动流条件下圆柱绕流场特性,对涡量分布、升阻力系数、升力系数频谱特性等进行分析。结果表明:脉动流作用会使圆柱尾涡剪切层变薄,提高脉动频率使尾涡长度变短、脱离加快,提高无量纲脉动振幅使主导涡的脱落速度降低,使旋涡生成区域更靠近圆柱表面;脉动频率与无量纲脉动振幅的增大使升力系数、阻力系数的振幅均增大,而且与升力系数相比,阻力系数的振幅更大,变化更快;升力系数频谱图存在多个主频,包括旋涡脱落频率和相位叠加频率,其中旋涡脱落频率的振幅随着脉动频率的增加而减小,随着无量纲脉动振幅的增加而增加。在流场中加入脉动流,可以增强流体振动促进流动混合。In order to investigate the effects of pulsating flow on structure around fluid,a numerical simulation was used to study the characteristics of the flow field around the cylinder under pulsating flow.The study focuses on vorticity distribution,lift coefficient,resistance coefficient and frequency spectrum of lift coefficient.Results indicate that the effect of pulsating flow will make the cylindrical tail vortex shear layer thinner.Increasing the pulsation frequency will shorten the length of the tail vortex and accelerate the separation.Increasing the dimensionless pulsation amplitude will reduce the shedding speed of the dominant vortex and make the vortex generation area closer to the surface of the cylinder.Both the amplitude of lift coefficient and resistance coefficient will be increased with the increasing of the pulsation frequency and the dimensionless pulsation amplitude.The latter is larger and varies more quickly than the former.There are multiple main frequencies in the lift coefficient spectrogram,including the vortex shedding frequency and the frequencies obtained by phase superposition.The amplitude of the vortex shedding frequency decreases with the pulsation frequency increase,and increases with the dimensionless pulsation amplitude increase.Adding pulsating flow to the flow field can enhance fluid vibration and promote flow mixing.

关 键 词：圆柱绕流 脉动流 旋涡脱落 升阻力系数 数值模拟 

分 类 号：O351[理学—流体力学]