Based on the phase-field theory, a new wetting boundary condition (WBC) scheme is proposed to describe the fluid–solid interaction of binary fluids. Different from the common linear, cubic and sine form of surface energy wetting conditions, we adopt a mixed cubic and sine form of free energy in the present scheme. Two conditions are given to ensure that the spurious film at the solid surface disappears and the reasonable boundary condition is obtained. Combined with the wetting scheme and lattice Boltzmann (LB) method based on phase-field theory, numerical simulation of droplet spreading on a cylindrical surface is carried out to verify the performance of the present WBC. It is found that the present wetting scheme can offer considerable accuracy for predicting a static contact angle, which means that it can be used to study the wetting boundary problems of binary fluids.

中文翻译：

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基于相场晶格玻尔兹曼法的二元流体替代润湿边界条件


基于相场理论，提出了一种新的润湿边界条件 （WBC） 方案来描述二元流体的流-固相互作用。与表面能润湿条件的常见线性、三次和正弦形式不同，我们在本方案中采用了自由能的三次和正弦混合形式。给出了两个条件，以保证固体表面的伪膜消失并获得合理的边界条件。结合润湿方案和基于相场理论的晶格玻尔兹曼 （LB） 方法，对液滴在圆柱面上的扩散进行了数值模拟，验证了该 WBC 的性能。研究发现，目前的润湿方案可以为预测静态接触角提供相当的精度，这意味着它可以用于研究二元流体的润湿边界问题。