Moving surface mesh-incorporated particle method for numerical simulation of a liquid droplet

• Published in: Journal of computational physics 2020-05, Vol.409, p.109349, Article 109349
• Main Authors: Matsunaga, Takuya, Koshizuka, Seiichi, Hosaka, Tomoyuki, Ishii, Eiji
• Format: Article
• Language: English
• Subjects: Computational fluid dynamics; Computational physics; Computer graphics; Computer simulation; Deformation; Differential equations; Domains; Droplet dynamics; Droplets; Finite element method; Fluid flow; Formability; Free surfaces; Hydrostatic pressure; Incompressible flow; Least squares MPS method; Meshfree particle method; Moving surface mesh; Operators (mathematics); Patch tests; Surface tension; Vapor phases
• ISSN: 0021-9991; 1090-2716
• DOI: 10.1016/j.jcp.2020.109349

In this study, a new particle method for simulating the dynamics of a liquid droplet in a two-dimensional space has been developed. The proposed method incorporates a moving surface mesh to represent a deformable free-surface boundary. The domain enclosed by the surface mesh is defined as a liquid volume (droplet), and the outer region is a gas phase with constant pressure. Fluid particles are seeded inside the liquid domain, and also, discrete nodes along the surface mesh are defined as additional computational points. The incompressible flow is solved based on the LSMPS (least squares moving particle semi-implicit) method, where all differential operators are discretized by means of consistent schemes. The stress balance equations are solved along free surfaces, where the surface tension force is directly evaluated by the geometry of the surface mesh at each surface node. As numerical tests, various problems including a hydrostatic pressure problem, circular and square patch tests, droplet oscillations and static droplets suspended by solid walls have been simulated. As a result, the proposed method shows excellent agreement with the reference solutions, even under large free-surface deformations, which verifies the validity of the current developments.