Numerical Study for Estimating Drag and Lift Forces Acting on a Spherical Bubble in a Homogeneous Shear Flow.

Abstract

Drag and lift forces acting on a spherical bubble in a homogeneous linear shear flow are numerically studied by means of a three-dimensional direct numerical simulation based on a marker and cell (MAC) method for high Reynolds numbers of 0.5&Re&200. The effects of fluid shear rate and the Reynolds number on drag and lift forces acting on a spherical bubble are compared with those on a spherical solid particle. The results show that the drag on a spherical bubble in a linear shear flow increases with the shear rate. The lift force acts on a spherical bubble from the low-speed side to the high-speed side in a linear shear flow. The direction of the lift force on a spherical bubble is different from that on a spherical solid particle for Re≥100. The difference can be well explained with the distributions of pressure and viscous lift acting on the surfaces of bubble and solid particle.