Numerical simulation of a water droplet splash: Comparison between PLIC and HRIC schemes for the VoF transport equation

Abstract

A wide range of natural and industrial processes, such as a droplet falling in the ocean as well as the injection of fuel in an internal combustion engine, are physically explained by the study of multiphase flows. The understanding of these processes is a fundamental step in order to optimize their use in industrial applications. Computational tools have been increasingly used for that purpose. This paper concerns the simulation of a water droplet of 2.9 mm diameter impacting onto a water pool with two different free falling velocities, 1.55 m/s and 2.5 m/s. The simulations were run using the Volume of Fluid method, which captures the interface between two fluids by solving a transport equation for the volume fraction. As demonstrated in many previous investigations, the solution of this phase transport equation is far from trivial. Therefore, in order to better understand the influence of the scheme for the advection term of the VoF transport equation, two different schemes are used, namely HRIC and PLIC. The CFD software Convergent Science Inc.’s CONVERGE TM CFD, which adopts adaptive mesh refinement techniques (AMR), is used to carry out the simulations. The results are then compared to experimental data. It is concluded that the VoF method with both schemes is able to track the surface between the fluids with good accuracy. Furthermore, the PLIC scheme maintains a sharper interface than the HRIC scheme as well as is more accurate and computationally efficient than the HRIC. These observations can be extended to other two-phase flow simulations.