Controlled coalescence with local front reconstruction method

Abstract

The physics of droplet collisions involves a wide range of length scales. This poses a difficulty to accurately simulate such flows with traditional fixed grid methods due to their inability to resolve all scales with affordable number of computational grid cells. A solution is to couple a fixed grid method with simplified sub grid models that account for microscale effects. In this paper, we incorporate such framework in the Local Front Reconstruction Method (Shin et al., 2011). To validate the new method, simulations of (near) head on collision of two equal tetradecane droplets are carried out at different Weber numbers corresponding to different collision regimes. The results show a better agreement with experimental data compared to other fixed grid methods like Front Tracking (Pan et al., 2008) and Coupled Level Set and Volume of Fluid (CLSVOF) (Kwakkel et al., 2013), especially at high impact velocities.