基于Soret和Dufour效应的方腔内双扩散自然对流振荡特性研究  

Oscillating Characteristics of Double Diffusive Natural Convection With Soret and Dufour Effects in Square Cavities

作　　者：娄钦[1] 罗祝清 王俊[1] 徐洪涛[1] 陈建[1] 

机构地区：[1]上海理工大学能源与动力工程学院,上海200093

出　　处：《应用数学和力学》2018年第2期147-159,共13页Applied Mathematics and Mechanics

基　　金：国家自然科学基金(51406120)~~

摘　　要：采用格子Boltzmann方法模拟研究了方腔内带Soret效应和Dufour效应的双扩散自然对流振荡特性.方腔内置高浓度发热圆且位于方腔中心,四周壁面均为低温低浓度.采用时间历程分析法和功率谱法分析了不同的浮升力比Br(2.0≤B_r≤10.0)、Soret数Sr(-0.6≤S_r≤0.0)和Dufour数Df(-0.6≤D_f≤0.0)下的方腔内部流动的振荡特性.研究结果表明:不考虑Soret和Dufour效应时,方腔内部流动呈现稳定状态,随着Df和Sr从0.0变化到-0.6,双扩散自然对流状态开始逐渐转变为周期性振荡和非周期性振荡,且振荡性随着浮升力比Br的增大而增强.The lattice Boltzmann method was adopted to study the oscillating characteristics of double diffusive natural convection in square cavities with Soret and Dufour effects. The inner heating cylinder with high concentration was located at the center of the cavity and the 4 surrounding walls were assumed to be at low concentrations and temperatures. The impacts of buoyancy ratio Br（2. 0≤B_r ≤10. 0）,Soret number Sr（-0. 6≤S_r ≤0. 0） and Dufour number Df（-0. 6≤D_f ≤0. 0） on the oscillating characteristics in the cavity were analyzed with the time history method and the power spectrum method. The results show that the flow state is steady at Sr = 0. 0 and Df = 0. 0. With decreasing Sr and Df from 0. 0 to-0. 6,the state of double diffusive natural convection turns into the periodic state and in turn the aperiodic oscillatory state gradually. Moreover,the positive buoyancy ratio enhances the oscillating characteristics.

关 键 词：Soret和Dufour效应 方腔 双扩散自然对流 振荡特性 格子BOLTZMANN方法 

分 类 号：TK124[动力工程及工程热物理—工程热物理]