Sedimentation of a Rigid Sphere in a Bubbly Fluid
W. G. Pritchard Laboratories
Department of Mathematics
Penn State University, USA
The transient and steady state motion of a falling sphere through a fluid depends to a large degree on the material properties of the fluid medium, be it Newtonian, Stokes, viscoelastic, or something more complicated. A field of rising bubbles provides a convenient way to slow down or even reverse the sedimentation of a heavy sphere, and is utilized in some industrial applications. I will present an experimental and mathematical study of a single sphere descending through a bubbly fluid in a quasi-2D geometry (with Reynolds numbers around 10^3), focusing on the transitions from falling to floating, and to a diffusive-type motion. This is joint work with Michael Higley.