Effect of Density-Induced Natural Convection on Solution of a Bubble under a Plate

Abstract

The solution process of a single gas bubble in liquid was simulated by directly solving gas diffusion equation in liquid, the vorticity transport equation and the Poisson equation for the stream function in order to estimate the effect of natural convection due to the difference in concentration on the solution process. Solution times of a single gas bubble under a plate were measured experimentally in order to estimate the diffusion coefficient of gas in liquid. Both the experimental and theoretical results reveal that solution time is affected by the natural convection due to the concentration difference in the case of large initial bubble radius. In the region where the effect of the density induced natural convection is not large, the process of solution is governed by two nondimensional parameters and consequently, the conditions where the process of solution is not affected by natural convection are clarified.