Destruction of Stratification by Bubble Plume

Abstract

Experiments are conducted on the evolution by a bubble plume of the density distribution in a closed container. Two initial distributions are studied, two uniform layers and a continuous linear stratification. The structure of the induced liquid plume and layering of the environment are observed from shadowgraphs. The density profile in the environment is measured. In a step stratification, the liquid plume impinges on the interface and splits into two flows. A small flux is carried in the wake of the bubbles into the upper layer, but the larger flux entraines some upper‐layer fluid and then flows into the top of the lower layer. If the distribution is initially linear then three layers are formed. The upper and lower are similar to the two layers of a step distribution. In the middle layer the stratification is linear, and the liquid plume is of constant diameter. This linear layer reduces in thickness with time, and after it is gone, the evolution is that of the step distribution.