Rayleigh对流及其对界面传质影响模拟的格子Boltzmann方法

针对乙醇吸收CO₂过程中，由CO₂通过界面向液体乙醇传递所导致的Rayleigh对流现象的模拟，建立了二维格子Boltzmann方法（LBM）。采用浓度分布函数和流体质点密度函数的双分布模型格子Boltzmann方法，同时引入由浓度差导致的重度差作为外加力，实现了流体中浓度场与速度场的模拟。应用所建立的LBM方法，对界面具有多个离散CO₂扩散源的二维区域液相Rayleigh对流现象进行了模拟，结果显示，模拟得到的浓度分布结构与文献中实验结果相一致。通过考察Rayleigh对流和浓度分布结构，分析了Rayleigh对流存在条件下的传递规律。通过采用LBM方法对浓度场模拟可以定量给出液相界面瞬时传质通量。计算结果表明，瞬时传质通量随时间的增长先增加后减小，这种变化与

Rayleigh convection and its effect on interfacial mass transfer by lattice Boltzmann simulation

In an interfacial mass transfer process,the concentration gradient of the transferred component builds up in the vicinity of the interface.The concentration gradient may generate density difference near the interface.If the density gradient directs opposite to the gravity,the interface is known as in Rayleigh instability and Rayleigh convection may occur in case of perturbation.Rayleigh convection is an interfacial phenomenon usually observed in mass transfer processes and in material processing industries....