Study on contact area of pool boiling bubbles on a heating surface. (Observation of bubbles in transition boiling)

Abstract

The contact area of boiling bubbles on the horizontal heating surface of transparent glass was observed from the back side of the heating surface through a transparent fused salt in transition boiling. The boiling liquid was Freon R-113, and the experiment was performed under the saturation condition at atmospheric pressure. The behavior of bubbles and liquid on the heating surface was observed in transition boiling by means of photography. As a result, the ratio of the area of the microlayer in contact bubbles on the heating surface to the total area of the heating surface decreased and the ratio of the dry contact area of the bubbles on the heating surface increased with increasing of the superheat of the heating surface.