Numerical simulation of two phase flow of a 3-Dimensional bubble

Three-dimensional simulations are presented on the motion of a deformable bubble in a combined coquette and poiseuille flow at finite Reynolds number. The full Navier-Stokes equation are solved by a finite volume method on a regular, fixed and staggered grid. Interface is tracked by marker points on an irregular, triangle and moving grid. The effect of surface tension is included. The effects of capillary number and Reynolds number on the lateral migration of a bubble are studied. It is found that a bubble migration to an equilibrium position about halfway between the wall and the centerline regardless of its original position. Simulations also show that the bubble shape is strongly dependent on the capillary number. As the Reynolds number increases, the effect of viscosity decreases and the equilibrium position moves closer to the wall. The effect of the radius of a bubble is also examined. With increasing the radius of the bubble, the centroid of the bubble moves to the centerline. The bubbles are more deformed with negative pressure gradient and migrate to the centerline.