A free energy-based surface tension force model for simulation of multiphase flows by level-set method

JOURNAL OF COMPUTATIONAL PHYSICS

卷:345

Article

Yuan, H. Z.^1,2  Chen, Z.²  Shu, C.²  Wang, Y.²  Niu, X. D.³  Shu, S.¹ 

[1] Xiangtan Univ, Sch Math & Computat Sci, Xiangtan, Hunan, Peoples R China

[2] Natl Univ Singapore, Dept Mech Engn, 10 Kent Ridge Crescent, Singapore 119260, Singapore

[3] Shantou Univ, Coll Engn, Dept Mechatron Engn, Shantou, Peoples R China

关键词: Surface tension force;    Multiphase flow;    Level set method;    Phase field method;    Large density ratio;   

DOI  :  10.1016/j.jcp.2017.05.020

来源: Elsevier

【 摘 要 】

In this paper, a free energy-based surface tension force (FESF) model is presented for accurately resolving the surface tension force in numerical simulation of multiphase flows by the level set method. By using the analytical form of order parameter along the normal direction to the interface in the phase-field method and the free energy principle, FESF model offers an explicit and analytical formulation for the surface tension force. The only variable in this formulation is the normal distance to the interface, which can be substituted by the distance function solved by the level set method. On one hand, as compared to conventional continuum surface force (CSF) model in the level set method, FESF model introduces no regularized delta function, due to which it suffers less from numerical diffusions and performs better in mass conservation. On the other hand, as compared to the phase field surface tension force (PFSF) model, the evaluation of surface tension force in FESF model is based on an analytical approach rather than numerical approximations of spatial derivatives. Therefore, better numerical stability and higher accuracy can be expected. Various numerical examples are tested to validate the robustness of the proposed FESF model. It turns out that FESF model performs better than CSF model and PFSF model in terms of accuracy, stability, convergence speed and mass conservation. It is also shown in numerical tests that FESF model can effectively simulate problems with high density/viscosity ratio, high Reynolds number and severe topological interfacial changes. (C) 2017 Elsevier Inc. All rights reserved.

【 授权许可】

Free