Role of horizontal crossflow on gaseous bubble passage through the liquid–liquid interface

Abstract

The present work reports a computational analysis of gaseous bubble bypass through the liquid–liquid interface in the presence of horizontal crossflow. The volume of fluid methodology is employed to carry out the simulations using multiphaseInterFoam solver from the open-source package OpenFOAM. The immiscible liquids are considered as viscous and Newtonian. Efforts are made to elucidate the bubble penetration and subsequent entrainment of liquid lamella within the lighter phase. Furthermore, the bubble passage phenomenon is delineated by considering different bubble sizes, D (2.5–7.5 mm). The entrained lamella retracts early in the presence of crossflow. Reynolds number (Ref) is employed to specify the strength of crossflow. The pattern of vertical as well as horizontal shifts of bubble is predicted when it is traversing from the heavier to the lighter phase. The vertical and horizontal shifts of a same-sized bubble progressively reduce and increase, respectively, with the rise of crossflow strength at a particular time stamp. Moreover, we have also predicted the behavior of drainage Hd/hg and retention Hr/hg height along with corresponding times by considering important pertinent parameters. The drainage and retention height are noticed to be lower and higher, respectively, with the rise of crossflow strength for a constant bubble size. We have further attempted to predict a regime map to distinguish two important behaviors of bubble, namely, (i) gaseous mass sheared off (zone I) and (ii) no gaseous mass sheared off (zone II). Finally, velocity vectors are employed to characterize the flow pattern of bubble passage through the liquid–liquid interface with the supplementary effect of crossflow.