BUBBLE DYNAMICS IN FLUID PUMPING AND FORMATION OF SPRAYS AND JET

Abstract

An oscillating bubble near a plate with a hole fully submerged in liquid leads to pumping from one side of the hole to another due to the jet induced in the bubble. In the first part of the thesis, the effect of viscosity of the fluid on the formation of the jet and the subsequent pumping was studied, both qualitatively and quantitatively. When the plate is situated at the liquid surface, a bubble nucleated below the hole. leads to two jets of liquid, a slow primary jet during its expansion and a faster second jet due to bubble collapse. The interaction between the jets leads to a thin liquid sheet with a ring of droplets. In the second study, the formation of such impacting jets is presented. at the micrometer length scale and replicated at millimetre length scale to understand the mechanism involved. High-speed photography is used in all studies.