Cell alternation algorithm for simulating bubble growth in boiling flows through volume of fluid (VOF) method in fluent

Abstract

This study focuses on the numerical illustration of bubble growth and addresses the inherent interface deformation problem associated with phase change in the Volume of Fluid (VOF) interface tracking method. To avoid the interface deformation, this study proposes a cell alternation algorithm that could simulate bubble growth with a sharp interface. The proposed algorithm identifies two types of cells near the vicinity of the interface, which include the primary-interface-cell and small-interface-cell. This algorithm computes mass transfer associated with a phase change at the primary interface cell and relocates it to a nearby cell full of vapor. The predictive accuracy of the proposed method is assessed with a one-dimensional Stefan phase change problem. In the case of the Stefan phase change problem, the results of simulations agree well with the results of the theoretical solution, and the predictive accuracy increases as the grid are refined. In addition, the proposed method is verified with two engineering problems which include bubble growth on a constant temperature surface and bubble growth in a microchannel. The simulation results show a good agreement with the results of the experiment in terms of bubble growth rate, bubble shape, and other parameters associated with experiment. Also, an insight into the temperature and velocity fields is provided in simulation which cannot be achieved directly through experiment.

Keywords

• Bubble growth
• VOF method
• Phase change
• Interface deformation