长矩形腔体中混合流体的双局部行波  

Double localized traveling waves of binary fluid mixturein a long rectangular cavity

作　　者：宁利中[1] 宁碧波 郝建武[1] 田伟利[3] 张珂 NING Lizhong;NING Bibo;HAO Jianwu;TIAN Weili;ZHANG Ke(Faculty of Water Resources and Hydro-electric Engineering,Xi'an University of Technology,710048 Xi'an,China;College of Civil Engineering and Architecture,Jiaxing University,314001 Jiaxing,China;Department of Architecture,Shanghai University,200444 Shanghai,China)

机构地区：[1]西安理工大学水利水电学院,西安710048 [2]嘉兴大学建筑工程学院,嘉314001兴 [3]上海大学建筑系,上海200444

出　　处：《应用力学学报》2024年第3期691-697,共7页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金资助项目(No.10872164);西北旱区生态水利国家重点实验室基金资助项目(No.2017ZZKT-2)。

摘　　要：基于数值模拟,研究了分离比ψ=-0.4和长高比Γ=40的腔体内的双局部行波对流的动力学特性。结果发现,对流圈在端壁产生,向中心传播,到达一定位置对流圈消失;在矩形腔体中两端壁附近行波对流区域与中间部位无对流的传导区域同时共存,形成双局部行波对流;双局部行波对流中的行波由腔体两端向中部传播;腔体二分之一高度处的温度与垂直流速分布是谐波结构,波形比较光滑,浓度分布是台型结构;随着时间的发展,垂直流速最大值稳定在某个数值周期变化,下壁面努塞尔数基本稳定在某个数值,垂直流速最大值和下壁面努塞尔数及其达到稳定的时间随着相对瑞利数r的增加而增加;双局部行波对流稳定的存在于相对瑞利数r∈{1.52,1.57]的区间,双局部行波的对流区长度随着相对瑞利数r的增加呈良好的增加关系,并给出了双局部行波的对流区长度随着相对瑞利数r变化的拟合关系式。Based on numerical simulation,the dynamic characteristics of double localized traveling wave(DLTW)convection in a cavity with separation ratioψ=-0.4 and an aspect ratioΓ=40 are studied.The results show that convective roll is generated at the two end wall,propagates to the center and disappears at a certain location.The traveling wave convection region near the two ends of the rectangular cavity coexists with the conduction region without convection in the middle,forming a DLTW convection.Traveling waves propagate from both ends of the cavity to the middle of the DLTW convection.Temperature and vertical velocity distributions in the midheight of the cavity are harmonic structures with smooth waveforms.Concentration distribution is a platform structure.With the development of time,the maximum vertical velocity stabilizes at a certain value and changes periodically.The Nusselt number of the lower wall is basically stable at a certain value.The maximum vertical velocity and Nusselt number on the lower wall and the time for them to reach stability increase with the increase of reduced Rayleigh number.DLTW convection is stable in the range of reduced Rayleigh number r∈{1.52,1.57].The length of convective zone of DLTW increases with the increase of reduced Rayleigh number.The fitting formula for the length of convective zone of DLTW varying with the reduced Rayleigh number is given.

关 键 词：双局部行波 对流 对流区长度 垂直流速最大值 努塞尔数 

分 类 号：O357[理学—流体力学]