Study of bubble dynamics and free liquid surface mixing in a rectangular container having ullage area with double gas inlets

Abstract

In this work, the Volume of Fluid (VOF) [1] method is used to study bubble dynamics and collapse of bubbles on free surface in a rectangular domain with double gas inlets. The simulation is done by using open-source CFD software OpenFOAM-3.0.1. The conservation equations for mass and momentum, which incorporates the influence of surface tension and gravity, are solved by using PIMPLE algorithm. The physical model for the simulation process is a 2D rectangular domain with a width of 50 mm and height of 100 mm. In order to study the collapsing of the bubble on the surface and free liquid surface mixing, an ullage area of 15% was considered within the domain. The numerical computation was performed with multiphase solver interFoam. Modeling of the geometry, meshing and setting the boundary conditions were done, using the OpenFOAM software. The simulation results were compared with the available literature results and found that the bubble formation and dynamics are in good agreement. The behaviors of gas bubbles emanating from two adjacent orifices at different gas velocities are studied. Mixing behavior in the bulk liquid due to bubble formation under different inlet gas velocities was also numerically investigated. The impact of surface tension and density of bulk liquid on collapsing of the bubble on the free liquid surface is investigated numerically.