The effect of Fe3O4 nanoparticles on the thermal conductivities of various base fluids

Abstract

Conventional heat transfer fluids have intrinsically poor heat transfer properties comparedto solids. Enhancing the efficiency of heat transfer is of great interest for various industrialapplications. Suspending solid particles in a fluid increases the thermal conductivity of theresulting suspension and enhances the heat transfer properties. In this work, changes in thermalconductivities of fluids upon the addition of magnetic nanoparticles have been investigated.Fe3O4 nanoparticles are synthesized using different synthesis methods and are suspended invarious oils. The effect of the base fluid and the type of magnetic particle on the thermalconductivity is investigated in detail. Up to 28% increase in the thermal conductivity isobtained with 2.5 wt% magnetic particles in hexane. The thermal conductivity enhancementis found to depend on the particle concentration, method of preparation and base fluid.The enhancements obtained are higher than those estimated using any theoretical modelpresent in the literature.