Nucleate boiling heat transfer performance of laser textured copper surfaces

Abstract

This paper reports the effect of channels/grooves developed on a copper surface by using a laser marking process on nucleate boiling heat transfer. Tests were conducted at atmospheric pressure and saturated pool boiling condition by using water as a pool liquid with varying heat flux values. Six different test sections are developed by varying laser power between 40-50 watts. The maximum enhancement in the heat transfer for laser processed surfaces was found to be 219% compared to plain surfaces. The present experimental investigation reveals that the laser marking process develops channels/grooves on the test surface with cavities inside them. The cavities inside channels/grooves act as active nucleation sites and channels/grooves provide a liquid path to the nucleation site, delaying a dry-out condition. © 2019 by Begell House, Inc.