Experimental investigation of heat transfer coefficient and correlation development for subcooled flow boiling of water-ethanol mixture in conventional channel

Abstract

In this present work, bubble dynamics of subcooled ?ow boiling in water-ethanol mixture is investigated through visualization using a high-speed camera in horizontal rectangular channels. The heat transfer coef?cient of water-ethanol mixture during subcooled ?ow boiling is determined for various parameters like heat ?ux, mass ?ux, and channel inlet temperature. The effect of bubble departure diameter on heat transfer coef?cient is discussed. A correlation is developed for subcooled ?ow boiling Nusselt number of water-ethanol mixture. The parameters considered for correlation are grouped as dimensionless numbers by Buckingham p-theorem. The present correlation is compared with the experimental data. The mean absolute error (MAE) of Nusselt number of water-ethanol mixture calculated from the experimental data and those predicted from the present correlation is 10.39%. The present correlation is also compared with the available literature correlations developed for water. The MAE of Nusselt number of water predicted from the present correlation and those predicted with Papel, Badiuzzaman, Moles-Shaw, and Baburajan correlations is 41%, 19.61%, 29.9%, and 43.1%, respectively. 2017 by ASM.