Numerical investigation on lateral migration and lift force of single bubble in simple shear flow in low viscosity fluid using volume of fluid method

Highlights: • A VOF simulation of bubble in low viscosity fluid was conducted. • Lift force in different viscosity fluid had different lateral migration characteristics. • Bubble with different size migrated to different direction. • Shear stress triggered the bubble deformation process and the bubble deformation came along with the oscillation behaviors. - Abstract: Two phase flow systems have been widely used in industrial engineering. Phase distribution characteristics are vital to the safety operation and optimization design of two phase flow systems. Lift force has been known as perpendicular to the bubbles' moving direction, which is one of the mechanisms of interfacial momentum transfer. While most widely used lift force correlations, such as the correlation of Tomiyama et al. (2002), were obtained by experimentally tracking single bubble trajectories in high viscosity glycerol–water mixture, the applicability of these models into low viscosity fluid, such as water in nuclear engineering system, needs to be further evaluated. In the present paper, bubble in low viscosity fluid in shear flow was investigated in a full 3D numerical simulation and the volume of fluid (VOF) method was applied to capture the interface. The fluid parameter: fluid viscosity, bubble parameter: diameter and external flow parameters: shear stress magnitude and liquid velocity were examined. Comparing with bubble in high viscosity shear flow and bubble in low viscosity still flow, relative large bubble in low viscosity shear flow keep an oscillation way towards the moving wall and experienced a shape deformation process. The oscillation amplitude increased as the viscosity of fluid decreased. Small bubble migrated to the static wall in a line with larger migration velocity than that in high viscosity fluid and no deformation occurred. The shear stress triggered the oscillation behaviors while it had no direct influence with the behavior. The liquid velocity had no effect on lift coefficient in the present research range of 0 < V < 0.186 m/s