Numerical Simulation of Buoyancy-Driven Motion of Drops in a Tube Using a Hybrid VOF-Level Set Method

摘要

Confined motion of drops and bubbles is encountered in a wide variety of industrial applications. In this study, we use a hybrid Volume of Fluid (VOF)-level set technique to study buoyancy-driven motion of a viscous drop in a tube at moderate Reynolds numbers. The numerical technique combines the best features of VOF and level set methods by moving the interface using the VOF, and computing the interface normal and curvature using the level set function. Numerical predictions of drop shape and mobility under low Reynolds number conditions are shown to be in good agreement with previous theoretical and experimental results. Numerical simulations are performed for different values of Reynolds number, capillary number, and viscosity ratio. It is found that increasing either the Reynolds number or the Capillary number leads to larger drop deformation and migration velocity.