Title: The Diffuse Solid Method for Wetting and Multiphase Fluid Simulations in Complex Geometries Show Chinese title

Title: 复杂几何形状下润湿和多相流体模拟的弥散固体方法

Abstract: We develop a diffuse solid method that is versatile and accurate for modeling wetting and multiphase flows in highly complex geometries. In this scheme, we harness N + 1-component phase field models to investigate interface shapes and flow dynamics of N fluid components, and we optimize how to constrain the evolution of the component employed as the solid phase to conform to any pre-defined geometry. Implementations for phase field energy minimization and lattice Boltzmann method are presented. Our approach does not need special treatment for the fluid-solid wetting boundary condition, which makes it simple to implement. To demonstrate its broad applicability, we employ the diffuse solid method to explore wide-ranging examples, including droplet contact angle on a flat surface, particle adsorption on a fluid-fluid interface, critical pressure on micropillars and on Salvinia leaf structures, capillary rise against gravity, Lucas-Washburn's law for capillary filling, and droplet motion on a sinusoidally undulated surface. Our proposed approach can be beneficial to computationally study multiphase fluid interactions with textured solid surfaces that are ubiquitous in nature and engineering applications. Show Chinese abstract

Abstract: 我们开发了一种扩散固态方法，该方法在建模高度复杂的几何图形中的润湿和多相流动时具有通用性和准确性。在此方案中，我们利用N+1组分的相场模型来研究N个流体组分的界面形状和流动动力学，并优化了如何约束用作固态相的组分演化以符合任何预定义的几何形状。展示了相场能量最小化和格子玻尔兹曼方法的实现方式。我们的方法不需要对流体-固体润湿边界条件进行特殊处理，这使得其实现起来非常简单。为了证明其广泛适用性，我们使用扩散固态方法探索了多种示例，包括平面表面上的液滴接触角、颗粒在流体-流体界面的吸附、微柱和水蕨叶结构上的临界压力、抵抗重力的毛细上升现象、毛细填充的卢卡斯-沃什伯恩定律以及正弦波波动表面上的液滴运动。我们提出的方法对于计算研究自然界和工程应用中普遍存在的具有纹理的固体表面的多相流体相互作用可能具有重要意义。