Heat transfer characteristics of free nanofluid impinging jet on flat surface with different jet to plate distance: An experimental investigation

Abstract

In the present study, the heat transfer characteristics of the impinging jet on the heated copper plate surface was investigated experimentally. Two different working coolants namely, DI water and aqueous Zinc oxide (ZnO) nanofluids with varying nanoparticle concentration (ϕ = 0.02%, 0.04%, 0.06%, and 0.1%) were used during the experiment. The ZnO nanofluids were synthesized by two-step methods. The experiments were conducted by impinging free circular jet fluids (water and ZnO nanofluids) on a 90 mm diameter and 3 mm thick heated copper plate. The jet parameters viz. nozzle to plate distance (2–7.5), the flow rate of fluids and nanoparticle concentrations were varied during experiments. This analysis reveals that there is a significant enhancement in heat transfer coefficient (HTC) for ZnO nanofluids coolant when compared with water coolant. During experiments, Reynolds number was varied in the range from 2192 to 9241. A theoretical correlation was developed after analyzing experimental data. The experimental results were found to be in good agreement with results obtained from theoretical correlation.