A density-based WCSPH numerical scheme for investigation of multiphase flows with intricate interfaces at high density ratios

Numerical investigation of multiphase problems having complex interface at high density ratios is one of the numerical challenges associated with particle scattering and divergence. Fewer problems have been performed using density-based smooth particle hydrodynamics (WCSPH) in order to solve complex joint surface currents, and most of the simulations in this field have been performed using incompressible smooth particle hydrodynamics (ISPH). Solving high density flows by smooth particle hydrodynamics is associated with particle dispersion and divergence. Various methods have been used to eliminate the scattering of particles, such as a repulsive force at the interface or the corrected density re-value, but there is a problem of particle disintegration at interface at higher times. Numerical simulations of SPH multiphase problems with high density ratio present divergence and dispersion of soluble particles over time simulation. However, this problem is solved in the current model so that continuity is preserved and provides a more accurate solution over time simulation. In the present work, in order to simulate multiphase flows with complex surfaces and high density ratios fluids investigation, a new density-based smooth particle hydrodynamic approach has been utilized. To prevent the particles scattering at the interface, an incompatible particle removal method is used. In the present study, a particle displacement optimization scheme for regularization at phase interface is created by implementing a two-stage change algorithm to maintain the regular particle distribution continuously and conservatively. In order to investigate the accuracy of the current numerical scheme, it is firstly compared with two-phase Poiseuille flow with three fluids having diverse values of viscosity, Reynolds-Taylor instability, Single Bubble rising in a fully filled container, merging of two bubbles, and Bubble rising in a partially filled container; then it is compared with analytical and numerical solutions.