Boiling Heat Transfer on Cylindrical Surface: An Experimental Study

Abstract

In this paper, pool boiling heat transfer data from experiments are presented to investigate bubble formation patterns and film growth on a large sized cylinder dipped in a pool. A wide range of heat flux has been applied over the cylinder to observe different regimes in boiling heat transfer. Nucleation, bubble merging during the transition, and sliding are captured through careful experimental efforts. Bubble sliding on the cylinder after inclining it with respect to horizontal has also been captured during the experiment which prompts the formation of large-sized bubbles on the surface. It has been established that the heat transfer coefficient varies nearly 2 times based on the azimuthal location of a large cylinder, bottom location of the cylinder showing the highest. Studies from inclined cylinder showed azimuthally bottom-most point of higher end has faster bubble release and highest heat transfer coefficient (∼2 times higher than top-most point of lower end). Spiral-like bubble motion has been noticed after detachment from nucleation sites over the inclined surface. Effect of cylinder surface inclination on boiling pattern has been also presented along with observations of bubble formation.