具有底部沉积层的槽道湍流中高Schmidt数溶解氧输运特性的大涡模拟研究  

Large eddy simulation of high-Schmidt-number dissolved oxygen transfer from turbulent flows to permeable microbial sediment bed

作　　者：田惠娟 李庆祥[1] 潘明[1] 董宇红[1,2] TIAN Hui-juan;LI Qing-xiang;PAN ming;DONG Yu-hong(Shanghai Institute of Applied Mathematics and Mechanics,Shanghai University,Shanghai 200072,China;Shanghai Key Laboratory of Mechanics in Energy Engineering,Shanghai University,Shanghai 200072,China)

机构地区：[1]上海大学上海市应用数学和力学研究所,上海200072 [2]上海市能源工程力学重点实验室,上海200072

出　　处：《水动力学研究与进展（A辑）》2018年第5期585-592,共8页Chinese Journal of Hydrodynamics

基　　金：国家自然科学基金(11572183)~~

摘　　要：该文采用大涡模拟方法研究了含有好氧细菌沉积层的槽道湍流中溶解氧穿越沉积层-水层交界面的高Schmidt数传质问题,并考虑了可渗透沉积层的各向同性属性和各向异性属性。采用动力学亚格子模型来封闭滤波后的三维不可压缩Navier-Stokes方程以及溶解氧浓度输运方程。基于壁面摩擦速度定义的Reynolds数为180,Schmidt数为373。修正的Darcy-Brinkman-Forcheimer模型和Monod方程用来描述底部充满好氧细菌的可渗透沉积层。通过流场和浓度场的统计特性如平均和脉动速度及浓度等物理量的研究,探究了不同沉积层参数对动量输运和溶解氧输运的影响。研究结果表明,随着流向达西数的增加或者各向异性程度减弱,对流扩散加快,Sherwood数增加,溶解氧消耗更快。High-Schmidt-number mass transfer of dissolved oxygen（DO） from turbulent flows to permeable microbial sediment bed is investigated by large eddy simulations. The different structures of isotropic and anisotropy of permeable sediments were considered. Dynamic subgrid-scale models are employed to close the three-dimensional filtered incompressible Navier-Stokes equations and the concentration equation for friction Reynolds number 180 and Schmidt number 373. The bottom sediment layer populated with DO-absorbing bacteria is described by a modified Darcy-Brinkman-Forcheimer model and Monod equation. The dependence of momentum and mass transfer on properties of sediment bed are analyzed by means of statistical quantities including the mean velocity, turbulent intensity and DO concentration et al. The present study reveals that with the increase of Darcy number or the weakening of anisotropy, convective diffusion accelerates, Sherwood number increases and the dissolved oxygen consumption is faster.

关 键 词：湍流 溶解氧输运 高Schmidt数 渗透沉积层 大涡模拟 

分 类 号：O357.5[理学—流体力学]