Fundamental behavior of heat and mass transfer in multicomponent mixtures featuring phase change materials in liquid metal suspensions and high vapor pressure fluids

Georgia Tech Research Corporation, Atlanta GA

Investigators

Abstract

Many electronic and industrial systems require increasingly higher heat removal capacities to accommodate the escalating heat produced by the micro-miniaturization of electronic components. Phase change materials have been commonly employed for thermal management; for example, fluids changing phase from liquid-to-vapor, and/or combinations of multiple fluids that change phases to improve thermal transport. This work proposes to study the use of novel multicomponent fluid mixtures to augment and improve the heat transfer rates. Multicomponent fluid mixtures in this study consist of mixtures of multiple fluids, solid particles that change phase to liquid, and refrigerants that can vaporize. The principal aim of this project is to provide a deep understanding of interactions among multicomponent fluid mixtures through both experimentation and simulations. This can then be used to further enhance the performance of many different types of heat transfer systems. The project will include significant educational activities, including the creation of educational materials for undergraduate and graduate programs using the associated research outcomes. This material will be modified for high school and middle school students through the creation of tutorials and video lectures. The investigation utilizes novel multicomponent fluid mixtures to augment internal convective and phase change heat transfer. The multicomponent fluid mixture refers to a novel mixture of multiple fluids and particles that includes phase change materials (PCMs), such as paraffin wax, suspended in liquid gallium alloys utilizing the stabilization properties of gallium oxide films around the suspended particles, in addition to a high vapor pressure refrigerant at saturation conditions. It is proposed that the gallium alloy properties can be improved by embedding PCM particles, such as paraffin wax that have a high heat capacity and low density. Further performance improvements are proposed through the deposition of a gallium oxide film on the channel wall, thereby increasing the wettability of the gallium alloy and consequently improving its mass transport. The proposed work will (i) develop a new understanding of the stability of various PCM particles/gallium alloy mixtures in a range of concentrations and the important properties of these mixtures; (ii) illuminate complex multi-fluid heat and mass transfer phenomena using liquid metals alongside high vapor pressure fluids; and (iii) illuminate the underlying mechanisms of the interactions in the multicomponent mixture. An Oscillating Heat Pipe (OHP) that is commonly used in thermal management applications will be studied with the proposed multicomponent mixture. The knowledge gained from this project has the potential to dramatically increase the efficiency of heat dissipation and transport in electronic and industrial systems. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.