复合方腔顶盖驱动双扩散混合对流格子Boltzmann模拟  

Lattice Boltzmann Simulation of Double Diffusive Mixed Convection in a Lid-Driven Composite Enclosure

作　　者：陆威[1] 王婷婷[1] 徐洪涛[1] 陈建[1] 杨茉[1] 

机构地区：[1]上海理工大学能源与动力工程学院,上海200093

出　　处：《工程热物理学报》2017年第3期640-647,共8页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No.51276117)

摘　　要：为本文基于热质耦合的Lattice Bhatnagar-Gross-Krook(CLBGK)模型,通过引入浓度分布函数,利用格子Boltzmann方法对顶盖驱动的复合方腔内的双扩散混合对流现象进行了研究,复合方腔由多孔介质区域和自由空间组成。分析了路易斯数Le=2.0,浮升力比N=1.0,格拉晓夫数Gr=10~4和普朗特数Pr=0.7时,孔隙率(ε=0.6/0.7/0.8)、方腔中多孔介质层位置及理查德森数Ri(10^(-3)≤Ri≤10~3)对内部混合对流及热质扩散的影响。给出了方腔内温度、浓度和流线分布,以及高温高浓度壁面的平均努塞尔数Nu_(av)和平均舍伍德数Sh_(av)。研究结果表明:多孔介质层对顶盖驱动方腔内热质双扩散影响显著,且方腔左壁壁面平均努塞尔数Nu_(av)与平均舍伍德数Sh_(av),在位置D_1~D_3之间随多孔介质层的右移而增大,在位置D_3上随Ri(10^(-3)≤Ri≤10~3)的增大而减小。Based on the coupled lattice Bhatnagar-Gross-Krook（CLBGK） model,this article adopts lattice Boltzmann method and introduces concentration distribution function to investigate the double diffusive mixed convection in a lid-driven composite enclosure,which is composed of the space filled with porous medium and free space of pure fluid.At Le=2.0,N=1.0,Gr=10^4,Pr=0.7,the influence of porosity（e = 0.6/0.7/0.8）,porous medium layer locations D_x and Richardson number Ri（10（-3）≤Ri≤10 ^3） on the double diffusive heat and mass transfer is performed.Results are presented in terms of isotherms,isoconcentrations,streamlines and the average Nusselt and Sherwood numbers along the left high temperature and concentration wall.Results show that the porosity and locations of porous medium have a significant influence on the doublediffusiveheat and mass in the lid-driven enclosure.The average Nusselt and Sherwood numbers along the left wall increase with the moving right of porous medium layer from D_1 to D_3 and decrease with the increasing of Ri from 10（-3） to 10^3.

关 键 词：复合方腔 顶盖驱动 双扩散 格子BOLTZMANN模拟 

分 类 号：TK124[动力工程及工程热物理—工程热物理]