一种新的混合流体对流竖向镜面对称对传波斑图  

A New-Type Counterpropagating Wave Pattern of Vertical Mirror Symmetry in Binary Fluid Convection

作　　者：宁利中[1] 渠亚伟 宁碧波[2] 袁喆[3] 田伟利[4] 刘爽 NING Li-zhong QU Ya-wei NING Bi-bo YUAN Zhe TIAN Wei-li LIU Shuang(Institute of Water Resources and Hydro-Electric Engineering, Xi＇ an University of Technology, Xi＇ an 710048, P.R.China School of Architecture and Civil Engineering, Jiaxing University, Jiaxing , Zhejiang 314001, P.R. China China Water Resources Pearl River Planning Surveying ＆ Designing Co. Ltd., Guangzhou 510510, P.R. China Department of Architecture, Shanghai University, Shanghai 200444, P.R. China)

机构地区：[1]西安理工大学水利水电学院,西安710048 [2]嘉兴学院建筑工程学院,浙江嘉兴314001 [3]中水珠江规划勘测设计有限公司,广州510610 [4]上海大学建筑系,上海200444

出　　处：《应用数学和力学》2017年第11期1230-1239,共10页Applied Mathematics and Mechanics

基　　金：国家自然科学基金(10872164);陕西省重点学科建设专项资金(00X901)~~

摘　　要：利用SIMPLE算法对混合流体对流的流体力学基本方程组进行了数值模拟,在混合流体分离比ψ=-0.6和矩形腔体长高比Γ=20的情况下,首次发现了一种新的竖向镜面对称对传波斑图,并初步探讨了它的动力学特性.竖向镜面对称对传波斑图的中心为驻波,随着时间的发展驻波的波长伸长.当波长增加到某个临界值时,一个滚动分裂成两个滚动,在这两个滚动之间产生一个具有180°相位差的新滚动.位于中心线上的滚动只有相位的突变及其波长的压缩或者伸长,没有对流滚动的移动,在它的两侧是向左右传播的对流滚动.驻波两次相位突变形成一个周期,驻波周期随着相对Rayleigh(瑞利)数Rar的增加而增加.这种对流结构存在于相对Rayleigh数Rar∈(3.6,4.3]的范围.当相对Rayleigh数Rar≤3.6时,系统出现具有缺陷的行波斑图;当Rar>4.3时系统过渡到行波斑图.说明竖向镜面对称对传波斑图是存在于具有缺陷的行波斑图和行波斑图之间的一种稳定的对流斑图.The 2D hydrodynamic equations for binary fluid convection were numerically simulated with the SIMPLE method. For separation ratio ψ =-0.6 of the binary fluid mixture and aspect ratio Γ= 20 of the rectangular cell,a new-type counterpropagating wave pattern of vertical mirror symmetry was found for the first time and its dynamics was preliminarily studied. At the center of the counterpropagating wave pattern of vertical mirror symmetry was a standing wave,of which the wavelength extended with time. As the wavelength increased to a certain critical value,a roll split into 2 rolls,and a new roll with a 180° phase difference formed between them 2. The roll located at the center line only has phase mutation and wavelength contraction or extension,without moving toward the left or right.The convective rolls propagating toward the left or right exist on both sides of the center line. The 2 phase mutations of the standing wave form a period,and the standing wave period increases with reduced Rayleigh number Rar. This type of convective structure exists in the range of Rar ∈（3.6,4.3].The convection system produces the traveling wave pattern with defect for Rar ≤ 3.6. The system shifts to the traveling wave pattern for Rar 4.3. The work shows that the counterpropagating wave pattern of vertical mirror symmetry is a stable flow pattern between the traveling wave pattern with defect and the traveling wave pattern.

关 键 词：竖向镜面对称 对传波斑图 驻波 数值模拟 混合流体 

分 类 号：O357[理学—流体力学]