This project aims to overcome barriers of state-of-the-art heat transfer fluids through developing and investigating a new type of fluid nanoemulsion fluids in which liquid nanodroplets are used to improve the thermal properties of the base fluids. Such fluids are expected to provide an unprecedented combination of highly desirable features for thermal applications, including high thermal conductivity, high heat capacity, long-term stability, and mass-production ability. This proposed effort will build on preliminary experimental results that demonstrate an unusually large improvement in the effective thermal conductivity up to a 52% increase for 12 vol % of water nanodroplets (19.6nm in diameter) in water-in-FC72 nanoemulsion fluids. This work represents the first experiments on the thermal conductivity of suspensions of liquid nanodroplets (<100nm in diameter) in heat transfer fluids.
Intellectual Merit: The key innovative aspects of the project are that nanoemulsion fluids will be developed and used as model systems to probe thermal transport in suspensions of nanoparticles. Various important factors that potentially affect thermal properties of such fluids, including particle mobility, particle size, and nonuniform distribution of particles, will be systematically investigated to address the long-debated mechanisms of thermal conductivity enhancement observed in suspensions of nanoparticles. The use of Phase Change Materials (PCMs) as nanodroplets will be explored to simultaneously improve the effective thermal conductivity and heat capacity of the base fluids. Various PCMs and base fluids will be investigated for determining PCM nanoemulsion systems suitable for thermal applications.
Broader Impacts: Improving the thermal properties of heat transfer fluids would result in substantial energy efficiency improvements across a wide range of industries. A graduate student and an assistant professor will be supported by this project, and undergraduate students will be exposed to this work by introducing nanoemulsion fluids into an undergraduate heat transfer laboratory course.
