A fully explicit SPH method for modeling 2-D incompressible two-phase fluid-structure interaction with modified periodic and open boundary conditions

Abstract

This study introduces a novel and effective method for simulating two-phase fluid-structure interactions (FSI) using the Explicit Incompressible Smoothed Particle Hydrodynamics (EISPH) approach. At the heart of our method is an explicit SPH framework specifically designed for two-phase rigid-body FSI, which significantly enhances computational accuracy and efficiency. A standout feature is the introduction of ghost particles, which facilitate periodic and open boundary conditions, ensuring stability and simplicity in complex fluid environments. Additionally, we employ a modified continuum surface tension model (M-CSF) to improve the smoothness and balance of force distribution at fluid interfaces. In a groundbreaking aspect of our work, we introduce and solve a new benchmark involving two-phase flow past a square obstacle for the first time. Alongside this benchmark, we validate our method against established cases such as single-phase and two-phase Poiseuille flow and Kelvin-Helmholtz instability. Through these validations, the EISPH-VKF method demonstrates its robustness and capability to accurately capture the intricate physics involved in both single- and two-phase FSI problems.