摘要
基于流体力学方程组的数值模拟,研究了倾角θ=90°时侧向加热的大高宽比腔体中的对流斑图.对于Prandtl数Pr=6.99的流体,在相对Rayleigh数2≤Ra r≤25的范围内,腔体中发生的是单圈型对流斑图.对于Pr=0.0272的流体,取Ra r=13.9,随着计算时间的发展,腔体中由最初的单圈型对流斑图过渡到多圈型对流斑图,这是出现在侧向加热大高宽比腔体中的新型对流斑图.对不同Ra r情况的计算结果表明,Ra r对对流斑图的形成存在明显的影响.当Ra r≤4.4时是单圈型对流滚动;当Ra r=8.9~11.1时是过渡状态;当Ra r≥13.9时是多圈型对流滚动.对流最大振幅和Nusselt数Nu随着相对Rayleigh数的增加而增加.该对流斑图与Pr=6.99时对流斑图的比较说明,对流斑图的形成依赖于Prandtl数.
The numerical simulation was carried out based on the hydrodynamic equations,and the convection patterns in cavities with large aspect ratios heated laterally at inclined angleθ=90°were studied.For the fluid with Prandtl number Pr=6.99 in the range of reduced Rayleigh number 2≤Ra r≤25,a single-roll type convection pattern occurs in the cavity.For the fluid with Pr=0.0272 and Ra r=13.9,with the development of calculation time,the convection pattern in the cavity transforms from the original single-roll type to the multi-roll type,which is a new type of convection pattern pertinent to large-aspect-ratio cavities heated laterally.The calculation results for different Ra r values show that,Ra r has a significant effect on the formation of convection patterns.A single-roll type convection pattern occurs for Ra r≤4.4;for Ra r=8.9~11.1,the system is in a transitional state;and a multi-roll type convection pattern appears for Ra r≥13.9.The maximum convection amplitude and Nusselt number Nu increase with Ra r.The comparison with the convection pattern for Pr=6.99 shows that the formation of the convection pattern depends on Pr.
作者
宁利中
张珂
宁碧波
吴昊
田伟利
NING Lizhong;ZHANG Ke;NING Bibo;WU Hao;TIAN Weili(Faculty of Water Resources and Hydroelectric Engineering,Xi’an University of Technology,Xi’an 710048,P.R.China;College of Civil Engineering and Architecture,Jiaxing University,Jiaxing,Zhejiang 314001,P.R.China;Department of Architecture,Shanghai University,Shanghai 200444,P.R.China)
出处
《应用数学和力学》
CSCD
北大核心
2020年第3期250-259,共10页
Applied Mathematics and Mechanics
基金
国家自然科学基金(10872164)。
关键词
单圈型
多圈型
对流斑图
侧向加热腔体
single-roll type
multi-roll type
convection pattern
cavity heated laterally
