An Interface-Corrected Diffuse Interface Model for Incompressible Multiphase Flows with Large Density Ratios
An Interface-Corrected Diffuse Interface Model for Incompressible Multiphase Flows with Large Density Ratios
复制标题
大密度比不可压缩多相流的界面校正扩散界面模型
DOI：
10.3390/app12189337
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发表时间：
2022-09
期刊：
影响因子：
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通讯作者：
Tongguang Wang
中科院分区：
文献类型：
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作者：
Yuhao Guo;Yan Wang;Qiqi Hao;Tongguang Wang
本文提出了一种界面修正的扩散界面法，用于模拟大密度比不可压多相流。在该方法中，在扩散界面Cahn-Hilliard模型中引入界面修正项和质量修正项，以同时保持质量守恒和界面形状不变。界面修正项是通过将Hamilton-Jacobian方程中的符号距离函数与Cahn-Hilliard模型的序参量相联系而得到的。此外，本文还提出了一种改进的多相格子Boltzmann通量求解器，该算法通过局部开关函数综合考虑粒子分布函数在流动过程前后的贡献来求解通量。通过模拟多相流，如拉普拉斯定律、方形气泡的演化、两气泡的合并、Rayleigh-Taylor不稳定性以及液滴撞击密度比为1000的薄膜等，验证了所提出方法的有效性。数值结果表明，该方法不仅能有效地抑制界面扩散，而且能很好地控制界面厚度和质量守恒。改进的数值方法在涉及多相流的实际应用中具有很大的潜力。
An interface-corrected diffuse interface method is presented in this work for the simulation of incompressible multiphase flows with large density ratios. In this method, an interface correction term together with a mass correction term is introduced into the diffuse-interface Cahn–Hilliard model to maintain both mass conservation and interface shapes between binary fluids simultaneously. The interface correction term is obtained by connecting the signed distance functions in the Hamilton–Jacobian equation with the order parameter of the Cahn–Hilliard model. In addition, an improved multiphase lattice Boltzmann flux solver is introduced, in which the fluxes are obtained by considering the contributions of the particle distribution functions before and after the streaming process through a local switch function. The proposed method is validated by simulating multiphase flows, such as the Laplace law, the evolution of a square bubble, the merging of two bubbles, Rayleigh–Taylor instability, and a droplet impacting on a film with a density ratio of 1000. Numerical results show that the presented method can not only reduce the interface diffusion but also has good control over the interface thickness and mass conservation. The improved numerical method has great potential for use in practical applications involving multiphase flows.