Characteristics of Nanofluid and Boiling Water on a Copper Finned Surface

Abstract

An experimental and computational investigation into the variations in boiling properties of different working fluids is presented in this paper. The diameter and frequency of bubbles in a working fluid define its boiling properties. When a fluid's heating surface, fluid in use, heat flux, and other variables vary, these properties also change. This study compared the changes in these boiling characteristics of five distinct working fluids, four of which are nano-fluids, in order to determine which one was the best. The finned surface was selected as the heating surface. Due to its larger surface area, the finned surface exhibits a higher heating value than the plain surface. Using water and 1% and 6% of -Water and CuO-Water as working fluids, high-speed visualizations of nucleate pool boiling at atmospheric pressure on a finned surface yield quantitative result. Theoretical studies of these working fluids are also done using correlations such as Rohsenow’s correlation, Cole correlation, Peebles and Garber Correlation. For computational analysis a modelling of boiling of working fluids is done. Results are compared to predictions from existing model of bubble nucleation behaviour. Graphs are plotted to show variation of bubble diameter and frequency against heat flux while variation of surface and saturation temperature with variation of heat flux determines which working fluid is more efficient. This study will help to understand the behaviour of nano-fluids as compared to normal fluids used in heat transfer applications. The study shows that experimental values of bubble frequency have variations compared to predicted values. In case of bubble diameter, the experimental values are found to be higher. Again, comparing experimental bubble diameter, bubble frequency and heat flux results the most preferable choice among these fluids from our study is 1% CuO-Water.