Development of a semi-empirical model for pool boiling heat transfer on metal foams

Abstract

This work aims the theoretical and experimental study of the pool boiling by using modified heating surfaces, surfaces modified by the addition of metallic foams. The research involves the development of experimental techniques and analysis of results with the collaboration of the IN+ research group at Instituto Superior Técnico (Lisbon - Portugal). The influence of surface characteristics on the heat transfer coefficient will be investigated, taking into account the properties of metallic foams, such as porosity, pore diameter, thermal conductivity, and foam thickness. The aspects involving the surface/fluid interaction will be studied through the analysis of the experimental data and the visualization of the phenomenon of boiling obtained with a high-speed camera. Detailed analysis of wettability and surface topology will be performed combining several experimental techniques, including confocal microscopy. The experimental tests will be performed for ethanol as a working fluid on copper and nickel open cell metal foams. The contribution of this work is to obtain a database with different work fluids, test surfaces, and experimental conditions in order to formulate a semi-empirical model for the prediction of the heat transfer coefficient in metal foams with fluids used in the cooling of electronic components and equipment of thermal control of machines in general. The choice of Dr. Ana S. Moita, a member of IN+/IST, as internship supervisor is due to work in the area of transport phenomena in liquid-solid interfaces, from macro to microscale, and in the development of diagnostic techniques for the characterization of these phenomena, for different applications (such as the development of cooling systems based on the boiling of quiescent liquids). (AU)