A Fundamental Study of Aeration in Oil 2nd Report : The Effects of the Diffusion of Air on the Diameter Change of a Small Bubble Rising in a Hydraulic Oil

Abstract

The results of a study about the effects of the diffusion of dissolved air on a small bubble rising due to buoyancy in a hydraulic oil are presented in this paper for both cases when pressure change is absent and when present. In the former case it is confirmed theoretically and experimentally that the dissolved air affects the process of the change in diameter of the bubble and that the diameter changes linearly with time in an oil when the air dissolved in it is not saturated. In the latter case the process of the change in diameter of the small amplitude is analyzed, and it is confirmed theoretically that the bubble may become larger even when the dissolved air is saturated at the average pressure.