考虑Soret和Dufour效应的方腔内双扩散自然对流格子Boltzmann模拟

采用格子Boltzmann方法，考虑Soret和Dufour效应，对内置高浓度发热圆的方腔内部双扩散自然对流现象进行数值模拟.高浓度发热圆位于方腔中心，四周壁面均为低温低浓度.在该模型中，用三个独立的LBGK方程分别模拟速度场、温度场和浓度场，并通过Boussinesq近似将它们耦合起来.分析Soret数和Dufour数对方腔内部双扩散自然对流的影响，得到流线图、等温线图、等浓度线图、发热圆表面平均Nusselt数和平均Sherwood数.结果表明：Soret和Dufour效应对方腔内双扩散自然对流影响明显，不能忽略.

Lattice Boltzmann Simulation of Double Diffusive Natural Convection in an Enclosure with Soret and Dufour Effects

We adopt lattice Boltzmann method to investigate double diffusive natural convection around a heated cylinder in an enclosure with Soret and Dufour effects. The inner heated cylinder is located at center of a square enclosure and four surrounding walls are assumed with low temperature and concentration. In the model, distributions of velocity, temperature and concentration are solved with three independent LBGK equations which are combined into a coupled equation through Boussinesq approximation. Influences of Soret number and Dufour number on double diffusive natural convection are analyzed. Streamlines, isotherms, isoconcentrations, average Nusselt and Sherwood numbers around heated cylinder in enclosure are presented. It shows that Soret and Dufour effects have significant influence on double diffusive natural convection.