Experimental Investigation of Forced Convective Heat Transfer Through Tube to Zinc Oxide-Water Nanofluid

This study focuses on development of Zinc Oxide-water (ZnO-H2O) nanofluid for heat transfer applications. ZnO-H2O nanofluid is a colloidal solution of zinc oxide nanoparticles in water. The required nanoparticles are produced by oxidation route and then nanofluid is synthesized from it by two step method and characterized. Characterization by X-ray diffraction, scanning electron microscope indicated mixture of nanorods of different shapes having average particle size of 32 nm. Synthesized nanofluid is circulated through heat transfer loop to assess its heat transfer performance in turbulent flow regime and at constant wall temperature condition when the fluid is being heated. Required experimental set up for heat transfer study is developed and validated. The result related to experimental investigation of synthesis and heat transfer to ZnO-H2O nanofluids is presented in this paper. Nanofluids of 0.15, 0.25, 0.5, 0.75, 1% volume fractions and Reynolds number range of 4000-20000 is considered for heat transfer study. Heat transfer and pressure drop characteristics of the nanofluid and water are compared. It is observed that the enhancement of heat transfer increases with increase in Reynolds number and decreases with increase in volume fraction of nanoparticles in the base fluid.