Motion of Air Bubbles in Mineral Oils Subject to Sudden Change in Chamber Pressure : 1st Report, Experimental Analysis of Single Spherical Bubbles

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This paper deals with an experimental and a theoretical analysis of growth and decay of a spherical air bubble rising in a stationary oil closed in a chamber subject to such a rapid rate of pressure variation as one bar during two or several milliseconds. The oils used were two kinds of base oils for hydraulic fluids with low and high viscosities, and base oils including a small quantity of silicon-type deforming agent were also used. The following are discussed from the comparison of the measured bubble motion with the numerical analysis: (1) mass transfer effect on expansion or compression of the bubble boundary. (2) effect of deforming agents added to the oil on the mass transfer through the bubble boundary, and (3) effect of surface dilational viscosity on violent bubble oscillation in a low viscosity oil.