局部行波对水平来流的依赖性

发布时间：2018-06-29 12:04

本文选题：Rayleigh-Benard对流 + 行波　；参考：《水动力学研究与进展(A辑)》2017年01期

【摘要】：水平来流和上下壁温度差的热作用使腔体内的流体发生运动,腔体内会呈现精彩的对流斑图。该文采用二维流体力学基本方程组的数值模拟,研究了普朗特数Pr=6.99时矩形腔体外加水平来流对局部行波对流结构的影响。由水平来流和垂直热作用的相互作用可获得均匀行波,局部行波和水平流三种对流斑图。在保持相对瑞利数r不变,水平来流雷诺数Re逐渐增大的情况下,可以得到均匀行波转变到局部行波的水平来流临界雷诺数Re,即局部行波存在的下临界雷诺数Re_l;局部行波转变到水平流的水平来流临界雷诺数Re,即局部行波存在的上临界雷诺数Re_u。通过改变相对瑞利数r发现了不同的水平来流临界雷诺数Re_l,Re_u。发现水平来流临界雷诺数随相对瑞利数r增大而增大;并给出了水平来流临界雷诺数Re_l,Re_u与相对瑞利数的函数关系式。同时对局部行波的结构进行了分析,可得局部行波的宽度随水平来流雷诺数的增大而减小。
[Abstract]:The horizontal flow and the heat effect of the temperature difference between the upper and lower walls make the fluid in the cavity move, and the convection pattern in the cavity will be splendid. In this paper, the effects of the external horizontal flow in a rectangular cavity on the local traveling wave convection structure with Plantt number pr = 6.99 are studied by numerical simulation of the basic equations of two-dimensional hydrodynamics. From the interaction of horizontal flow and vertical heat, three kinds of convection patterns can be obtained: uniform traveling wave, local traveling wave and horizontal flow. When the relative Rayleigh number r is kept constant, the Reynolds number of the horizontal flow increases gradually, We can obtain the critical Reynolds number of the horizontal flow from the uniform traveling wave to the local traveling wave, that is, the lower critical Reynolds number of the existence of the local traveling wave, and the critical Reynolds number of the horizontal flow from the local traveling wave to the horizontal flow, that is, the upper critical Reynolds number of the existence of the local traveling wave. By changing the relative Rayleigh number r, the critical Reynolds number of different levels is found. It is found that the critical Reynolds number of horizontal flow increases with the increase of relative Rayleigh number r, and the functional relationship between the critical Reynolds number of horizontal flow and the relative Rayleigh number is given. At the same time, the structure of the local traveling wave is analyzed. It is found that the width of the local traveling wave decreases with the increase of the horizontal flow Reynolds number.
【作者单位】：西安理工大学西北旱区生态水利工程国家重点实验室培育基地;嘉兴学院建筑工程学院;上海大学美术学院;
【基金】：国家自然科学基金项目(10872164) 陕西省重点学科建设专项资金资助项目(00X901)~~
【分类号】：O35

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