倾斜壁面浸润性梯度驱动液滴运动过程的格子Boltzmann模型研究

Lattice Boltzmann Simulation of the Dynamic Behavior of a Droplet Driven by Wettability Gradient on Inclined Surface

基于介观模型的多组分伪势格子Boltzmann方法,模拟了倾斜壁面浸润性梯度驱动液滴的运动过程,研究了壁面浸润性梯度、壁面倾斜角度对液滴运动过程的影响.结果表明,对于一定倾斜角度的壁面,当壁面上浸润性梯度足够大时,液滴能够克服重力的作用实现"爬坡";液滴在运动过程中,其前进及后退接触角与当地静态接触角间存在差值;增大壁面浸润性梯度时,液滴能够获得更快的加速,并且前进及后退接触角与当地静态接触角之间的差值也随之增大;增大壁面倾斜角度时,液滴的运动受到阻碍,前进及后退接触角与当地静态接触角的差值小幅减小.

The dynamic movement of a 2D droplet driven by wettability gradient on an inclined surface is investigated by using a multicomponent lattice Boltzmann method based on pseudopotential model. The effects of the wettability gradient and the inclination angle of the inclined surface on the behaviour of the droplet are presented. The results show that, as to an inclined surface with certain inclination angle, the droplet would start climbing the surface if the wettability gradient is large enough. The advance/retreat contact angles are different from the local static contact angle. When increasing the wettability gradient, the droplet will get a larger acceleration, and the difference between the local static angle and the advance/retreat contact angle will increase. When increasing the inclination angle of the surface, the motion of the droplet will be hindered, and the difference between the local static angle and the advance/retreat contact angle will decrease a little.