周期加热的Rayleigh-Benard对流时空结构  

Spatio-Temporal Structure of Rayleigh-Benard Convection Heated Periodically from Below

作　　者：宁利中[1] 李开继 周洋[1] 王永起[1] 胡彪[1] 

机构地区：[1]西安理工大学水利水电学院,陕西西安710048

出　　处：《力学季刊》2015年第3期485-492,共8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资金(00X901)

摘　　要：通过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时矩形渠槽周期加热对Rayleigh-Benard对流时空结构的影响.当水平流动强度Re=0时,发现稳定的由周期加热引起的局部定常对流.当Re比较小时,对流滚动抑制水平流动,获得了由周期加热引起的局部行波对流.当水平流动强度比较大时,由于周期加热与水平流动相互作用,水平流动抑制部分对流滚动,导致对流区域上游附近出现传导区域,对流区域减小,从而形成一种新的局部行波对流结构.并进一步讨论了Rayleigh-Benard对流时空结构的动力学特性.By using a two-dimensional numerical simulation of the fully hydrodynamic equations, the influence of periodic heating on the spatio-temporal structure of Rayleigh-Benard convection in a rectangular channel at Prandtl number Pr=6.99 was studied. For the horizontal flow Re=0, the stably localized stationary overtttrning convection caused by periodic heating was found. While the horizontal flow Re is less, convection rolls suppress horizontal flows, and the localized traveling wave convection caused by periodic heating was obtained. If the horizontal flow Re is larger, horizontal flows partly suppress convection rolls, the conduction region appears near the upstream of the convection area and the convection area decreases due to the interaction between periodic heating and horizontal flow. Thus, a new localized traveling wave convection was formed. Further, the dynamics of the spatio-temporal structure of the Rayleigh-Benard convection was discussed.

关 键 词：RAYLEIGH-BENARD对流 周期加热 时空结构 局部行波 动力学 

分 类 号：O357[理学—流体力学]