Smoothed particle hydrodynamics with adaptive spatial resolution for multiphase flows with large density ratio

The smoothed particle hydrodynamics (SPH) method has been increasingly applied to simulate multiphase flows with large density ratios, but the method is computationally expensive when a high resolution is needed. Traditionally a uniform spatial resolution (USR) is used in an SPH simulation. In our previous work, an adaptive spatial resolution (ASR) method was developed for use in the SPH simulations of multiphase flows; the spatial resolution changes adaptively according to the distance to the interface between different phases. In this paper, the SPH-ASR method for multiphase flows is improved by introducing a particle shifting technique to improve the distribution of particles. This particle shifting technique considers the variable smoothing length. The present SPH-ASR method is further enhanced by optimizing the algorithm for adaptive resolution. In addition, the current SPH-ASR method is extended from two- to three-dimensional applications. The improved SPH-ASR method is validated by simulating the dam-break flows, liquid drop formation, and drop impact on a solid surface. Results show that the present SPH-ASR method can greatly reduce the computational cost while maintain the same accuracy to the uniform resolutions.