具有多孔介质覆面层的柱体绕流流场分析  

Analysis of Flow Field Around a Cylinder with Porous Media Layer

作　　者：林品亮 冯欢欢 董宇红[1] LIN Pinliang;FENG Huanhuan;DONG Yuhong(School of Mechanics and Engineering Science,Shanghai University,Shanghai 200072,China)

机构地区：[1]上海大学力学与工程科学学院,上海200072

出　　处：《计算物理》2022年第4期418-426,共9页Chinese Journal of Computational Physics

基　　金：国家自然科学基金(12172207)资助项目

摘　　要：建立多孔结构覆面柱体绕流模型,采用含Darcy-Brinkman-Forchheimer作用力项的格子Boltzmann方程对覆盖多孔介质层的方柱绕流进行数值模拟,研究多孔介质对钝体绕流流场特性的影响。结果表明:相比于不可渗透壁的柱体,引入合适参数的多孔介质覆面层后可以有效降低其升力脉动幅值,但阻力有所增加。同时,较高雷诺数下多孔方柱的数值模拟表明:多孔介质壁面使得尾迹区域的剪切层相距更远,降低了尾流处湍动能,并将雷诺应力的峰值移动到尾迹区域,抑制了方柱两侧的动量交换,使动量交换的位置发生在尾迹区域,继而使得尾迹的涡街更加规则化。Flow around a square cylinder with porous media is numerically simulated by means of the lattice Boltzmann equation in Darcy-Brinkman-Forchheimer force model,and influence of porous media on flow field characteristics of bluff body is studied.It shows that:Compared with a impermeable cylinder,the flow structure is modulated by the porous media layer under certain parameters.Evolution of the shear layer tends to be more symmetrical and stable,which reduces the interaction of vortex motions in the wake region and makes the vortex shedding more periodic,thus reducing effectively the amplitude of lift fluctuation,but increasing the drag in some extent.At the same time,we study surface porous media effect on square column under high Reynolds number.It shows that the porous medium wall makes wake region of the shear layer farther apart,reduces the wake turbulence kinetic energy,and moves the Reynolds stress peak of the mobile to wake region,suppresses the momentum exchange on either side of the square column,makes the momentum exchange occurred in wake region and the vortex street of the wake more regular.

关 键 词：格子BOLTZMANN方法 多孔介质 钝体绕流 升力系数 

分 类 号：O357.5[理学—流体力学]