(440a) Rising Motion of a Swarm of Drops in a Linearly Stratified Fluid

The motion of drops and bubbles in stratified fluids has several natural and industrial applications such as bubbles rising across pycnoclines in marine and aquatic environments, oil spills, ocean sequestration of CO₂, and bubble mixers used for lake/reservoir destratification and aeration.  Even though the motion of bubbles and drops in a homogenous fluid has been extensively studies, their motion in a stratified fluid is poorly understood.  Here, the three-dimensional motion of a swarm of buoyant drops rising in a linearly stratified fluid is studied using a finite volume/front tracking method. Numerical simulations are performed to investigate the effects of stratification on the cluster formation and the mean rise velocity of the swarm of drops. The pair correlation function is calculated to characterize the microstructure of the dispersed phase. The simulations show stronger tendency to form clusters as stratification increases. The mean rise velocity of the swarm of drops is smaller compared to the one in a homogenous fluid.