The Behavior of a Deformable Bubble in an Accelerating Fluid

Abstract

The unsteady behavior of a deformable bubble in an accelerating fluid is analyzed numerically. The numerical method is based on a finite-volume solution of the equations on an orthogonal curvilinear coordinate system. The effect of the acceleration of the surrounding liquid is investigated by introducing the periodic body force in momentum equations. Numerical results reveal that theoretical model gives good predictions of bubble behavior as far as the deformation is small. However, the deformation gives much more complicated behavior. In this study, the deformation effect is classified into two types, depending on the ratio of the deformation time scale to that of translational motion and forcing. One is the type in which a shape oscillation is excited directly from the oscillatory body force field, and the other is the one in which a deformation is caused by a hydrodynamic interaction through the translational motion.