Joyce Lin, University of North Carolina, Chapel Hill


Sphere falling in stratified fluids at low Reynolds


Abstract: Low settling rates are observed for small particulate matter in strongly, stably stratified fluid. As the particle passes through an interface between two layers of fluid, it entrains lighter, upper fluid. The significance of this entrained fluid in the low Reynolds regime, along with a model for the behavior of the particle, has not yet been fully explored. We present careful measurements performed in stratified corn syrup showing the effects of the enhanced drag due to entrained fluid on the sphere at low Reynolds. We develop a model from first principles on the hydrodynamics, which involves a strong coupling between the variable density fluid and moving solid boundary.

Postdoctoral Mentor: Roberto Camassa and Rich McLaughlin (University of North Carolina, Chapel Hill)