The pressure in an enclosed volume of liquid in case of a rising bubble

Abstract

The paper considers the history of the hydrostatic pressure in a liquid hermetically confined to a fixed volume when a bubble rises in it. This case differs remarkably and substantially from the case of a liquid with a free surface. Under ideal conditions, it turns out that the bubble conveys its pressure from bottom to top causing a pressure rise of the entire liquid. A special experiment on laboratory scale demonstrates what the deviations from ideality amount to and how they can be explained. For bubbles of sufficient size, 95% of the ideal pressure rise could be gained. Although this effect is of notable technical importance, e.g., in pipeline engineering, it has escaped notice. Part of the explanation is that the effect seems so unlikely at first glance.