Numerical Simulation of Bubbly Flow by Vortex in Cell Method

A vortex in cell (VIC) method for bubbly flow is proposed. It computes the time evolution of the flow by calculating the behavior of the vortex element as well as the bubble motion with the Lagrangian approach. The proposed method is also applied to simulate a bubble plume to demonstrate the validity. In a tank containing water, small air bubbles are released from the base of the tank. The bubbles rise due to the buoyant force, inducing the water flow around them. The simulation for the plume at the starting period highlights that the rising bubbles induce vortex rings at their top and that a bubble cluster appears owing to the entrainment of the bubbles into the vortex rings. The rising velocity for the top of the bubbles is proportional to the square root for the flow rate of the released bubbles, being consistent with an existing theoretical investigation. The simulation also demonstrates that the developed bubble plume having jet characteristics is successfully captured.