Spray Impingement Heat Transfer Using Nanofluid—Experimental Study

Spray impingement plays a vital role in the cooling process. Spray impingement acts as a cooling media for high heat flux applications. As nanofluids have enhanced thermal properties than base fluids, CuO, ZnO, and hybridized CuO and ZnO nanofluids at different volume concentrations were used in this experiment. The nanoparticles were synthesized using high-energy ball milling (HEBM) technique at 300 rpm with the ball-to-powder ratio (BPR) of 10:1. These nanoparticles were characterized by using XRD, SEM, and TEM and were found to be in the range of 30 nm. The densities, viscosity, thermal conductivity, and the specific heat of the nanofluids were calculated using different models. It was observed that increase in the volume concentration, density, and viscosity of the nanofluid increased. The heat transfer study was carried out on an electrically preheated iron plate of dimensions 100 mm × 100 mm × 8 mm at different temperatures of 200, 150, and 100 °C. The cooling rate and the effect of air pressure on cone angle were analyzed. The main sources of uncertainty in the measured data were due to the temperature fluctuations and thermocouple locations. It was observed that the time taken to reach the steady state was faster in nanofluids than normal water.