THE EVOLUTION OF SLENDER BUBBLES IN AN EXTENSIONAL FLOW: INERTIAL EFFECTS

摘要

The influence of a small amount of external inertia on the evolution of a slender bubble in an extensional flow has been theoretically studied. The unsteady problem is governed by two parameters: The capillary number and the Reynolds number for the external flow. The unsteady shape of the bubble, described by a single partial differential equation, was transformed into a system of ordinary differential equations which was numerically solved. Contrary to the case where inertia is absent and breakup is not possible, a small amount of external inertia, above some critical level, can cause the bubble to break. We found the breakup mechanism to be that of center pinching.