Updated Lagrangian Particle Hydrodynamics (ULPH) modeling and simulation of multiphase flows.

• A weakly compressible ULPH model is developed for multiphase flows. • A new surface tension formula combined with interface sharpness force is developed in the ULPH multiphase flow model. • The intermediate configuration is considered in the computational algorithm. • Validations of ULPH multiphase flow model show good accuracy, stability and convergence. In this paper, a weakly compressible updated Lagrangian particle hydrodynamics (ULPH) model [1] has been developed for multiphase flows with high density ratios and viscosity ratios. To enhance computation stability and prevent penetrations near the multiphase flow interface, a new surface tension resultant formulation based on the Continuum Surface Force (CSF) formulation [2] , combined with the interface sharpness force, is also developed within the framework of ULPH method. The intermediate configuration is considered in the computational algorithm, and a modified predictor-corrector scheme is adopted to solve governing equations, which significantly improve the accuracy and efficiency of the ULPH model. Several numerical examples are presented to compare with either analytical or computational results obtained by using different numerical methods such as Smoothed Particle Hydrodynamics (SPH) method, Moving Particle Semi-implicit (MPS) method and Level Set (LS) method within the framework of Finite Element Method (FEM). The results indicate that the ULPH method has good accuracy, stability, and convergence properties in simulations of multiphase flows. [ABSTRACT FROM AUTHOR]