Effect of spinning on the shape and stability of a pendent drop.

Abstract

Assuming that we wish to measure the surface tension between two liquids by running a pendent drop experiment, we present calculations supporting the case for spinning the drop. For bridges, jets, etc., spinning a heavy fluid surrounded by a lighter fluid is strictly destabilizing. But we find that spinning a drop may be stabilizing and, if this is so, it leads to larger critical volumes, volumes where stability is lost, and thus more accurate measurements of surface tension. There are two observable patterns, one symmetric and the other unsymmetric, at the point of instability. The symmetric pattern leads to larger critical volumes. Our aim is to show how spinning can be used to achieve the symmetric pattern.