Growth and Collapse of Bubbles in Nucleate Boiling

Abstract

A number of theoretical and experimental studies on growth and collapse of bubbles have been made in order to clarify the boiling phenomena. Almost of those experiments, however, have been made with heating surface of smaller size than bubble diameter. Authors have been doubtful of the validity of applying such experimental results to boiling with larger heating surface. In order to clarify the dependence of the bubble growth and collapse upon the shape and size of heating surface, they carried out experiments by means of heating surfaces of horizontal circular brass plates 10 cm and 14 cm in diameter respectively and of horizontal small platinum wire 0.5 nm in diameter. From their experiments following facts were made clear. (1) Bubble growth and collapse are independent of heat flux. (2) Bubble collapse is strongly influenced by the degree of subcooling. (3) Bubble growth and collapse which essentially dominate boiling heat transfer are considerab1y affected by the size of heating surface. According to the above-mentioned facts, it may be concluded that one must be careful of applying the experimental results with a heating surface of a size smaller than bubble diameter to boiling with a larger heating surface.