格子Boltzmann方法模拟气泡生长脱离

Simulation of Bubble Growth and Departure Using Lattice Boltzmann Method

格子Boltzmann方法具有微介观的特性,能够自动捕捉和追踪界面,在多相流领域有广阔的应用前景。对于伴有气液相变的传热问题,格子Boltzmann方法已有模型较少,其中有一部分是通过质量变化间接反映相变过程,不能真实反映温度场的演化和影响。本文采用了模拟多相流动和分离的自由能模型,结合基于Stefan边界的相变传热模型,考虑壁面自由能对流体与壁面间润湿性的影响,模拟了静态接触角、过热壁面的气泡生长和脱离,并进行了更接近真实沸腾过程的随机生成气泡的模拟,以及流动沸腾的气泡生长和脱离的模拟。

Lattice Boltzmann method has microscopic and mesoscopic features to capture and track the interface automatically,and has been widely applied in the field of multiphase flow.For heat transfer with gas-liquid phase change,there are few lattice Boltzmann models,and part of them are indirectly reflected by quality change of the phase transition,which cannot truly reflect the evolution and impact of temperature field.In this paper,multiphase free energy model combined with phase change processing method based on Stefen boundary is used to simulate the static contact angle and the bubble growth and departure from a superheated wall,with the effect of wall free energy on the wettability is considered.And this method is applied to study the bubble growth and departure in the more realistic boiling process with randomly generated bubbles and the flowing boiling process.