Heat Transfer in a Contact Area of a Boiling Bubble on a Heating Surface

Abstract

A thin liquid layer and a dry part in a contact area of a boiling bubble on a wetted heating surface was clearly obserbed by experiment using an electro-conductive glass. The thickness of the liquid layer was calculated by reasonable assumption that the shape of a contact bubble on the heating surface is semi-sphere, etc. It was found to be a very thin layer (roughly 10 μ order). And then heat transfer through the thin liquid layer was calculated, and it was found that its coefficient of heat transfer in the contact area of the bubble was very good (roughly 105kcal/m2hr°C order). Therefore we could understand that in the boiling heat transfer a main part is played by the thin liquid layer in the contact area of the bubble.