摘要
腔体高度的改变会对Rayleigh-Bénard对流产生影响.本文利用二维流体力学基本方程组进行数值模拟,在相对瑞利数r(28)5,腔体高度0 0 0 0 0d(28)1d,1.4d,1.8d,2d,3d(cm10d(28))时,研究了对流运动的动力学特性,发现随着腔体高度d的增加,稳定对流的对流圈数与之呈线性反比例关系,而对流波数k随之基本保持恒定;对流稳定后,对流振幅和努塞尔数随腔体高度d增大而减小,且得出对流振幅和努塞尔数随着相对腔体高度0/dd变化的函数关系式.在腔体高度0 0 0d(28)1d,1.4d,1.8d情况下,对流振幅和努塞尔数都随相对瑞利数r的增大而增大;且腔体高度d越大,其增长率反而越小.
The cavity height has influence on Rayleigh-Bénard convection. A two-dimensional numerical simulation is carried out to study the dynamics of convective motion at reduced Rayleigh number r=5 and cavity height d=1 d0, 1.4 d0, 1.8 d0, 2 d0, 3 d0. Results find that the convection roll number of steady convection is inversely proportional to the height of the cavity, and the wave number k of steady convection essentially keeps constant with increase of the cavity height. The convection amplitude and Nusselt number decrease with increasing d after convection stability, and formulas for computing the convection amplitude and Nusselt number varying with relative cavity height d/d0 are acquired. The convection amplitude and Nusselt number increase with increasing of the reduced Rayleigh number r at cavity height d=1 d0, 1.4 d0, 1.8 d0. The growth rate is smaller for a larger cavity height.
作者
胡彪
宁利中
宁碧波
王新宏
田伟利
吴昊
宁景昊
HU Biao1;NING Lizhong1;NING Bibo2;WANG Xinhong1;TIAN Weili3;WU Hao 1;NING Jinghao1
出处
《力学季刊》
CSCD
北大核心
2018年第2期433-439,共7页
Chinese Quarterly of Mechanics
基金
国家自然科学基金(10872164)
陕西省重点学科建设专项(00X901)
关键词
对流波数
腔体高度
对流振幅
努塞尔数
convection wave number
cavity height
convection amplitude
Nusselt number
