VIII-1

Kevin DeBisschop and Michael Miksis

Northwestern University

Abstract

Here we consider the problem of a bubble or drop moving in an inclined channel. We consider only the small Reynolds number limit. The motion of the bubble is governed by gravity and an imposed pressure gradient. Solutions are found by using a boundary integral method. we study the behavior of the bubble as a function of the angle of inclination, the Bond number, the applied pressure gradient, the density and the viscosity ratio.

We find that as the Bond number increases, the steady state rise velocity of the bubble increases until a steady state no longer exists. After this point we find that a filament of liquid will begin to grow off of the side of the bubble which in some cases appears to detach from the drop interface. In addition, we also consider the effect of an insoluble surfactant on the bubble interface.