Characterization And Modeling Of Thermal Conductivity Of Zno Nanoparticle-Based Transformer Oil Nanofluid

Well dispersed ZnO nanoparticles were synthesized by hydrothermal method. The ZnO-transformer oil based nanofluids were prepared by dispersing as-prepared nanoparticles into pure base fluid. Thermal conductivity of the nanofluid was measured by the transient hot-wire method. A comprehensive theoretical model which considers the Brownian motion of nanoparitcles has been developed to explain the enhancement in thermal conductivity of nanofluid. Furthermore, the effect of the implementation model was tested through empirical research. The experimental result shows that the thermal conductivity is increased by 9% for the nanofluid containing 0.5% volumetric fraction of ZnO nanoparticles. The thermal conductivity predicted by the new model agrees well with the experimental data. In oil based nanofluid, the thermal conductivity does not follow the traditional Maxwell model. Theoretic analysis and experiments demonstrate a multiple transport mechanism with regard to the suspended nanoparticles' Brownian motion can effectively improve the understanding of thermal enhancement in oil based nanofluid.