Observation of flow and temperature oscillations around a bubble on a solid surface subject to a vertical temperature gradient

摘要

In space and many industrial cases on earth which involve materials processing, manufacturing, and storage and management of liquids, the interaction between gas and vapor bubbles with the surrounding is of great interest. Study of thermocapillary motions near bubbles attached to a heated or cooled wall in conjunction with the space experiments has received considerable attention in recent years. We present results of preliminary experimental observations which have indicated that when the marangoni number is increased beyond a critical value, a series of oscillatory modes develop in the vicinity of the bubble. The oscillations have been detected in both the basic flow induced by combined marangoni and buoyancy effects, by using a laser sheet for tracing particles, and in the temperature field visualized by interferometry techhniques. The influence of the Marangoni and Prandtl numbers and bubble geometry on the oscillations are indicated.