Heat transfer analysis using zinc Ferrite/water (Hybrid) nanofluids in a circular tube: An experimental investigation and development of new correlations for thermophysical and heat transfer properties

For heat transfer analysis, the thermal properties of the heat transfer fluid is aninterestingtopic of current research. The hybrid nanofluids have better effective thermal conductivity, which is being used to improve the heat transfer rate. This experimental study presents the heat transfer characteristic of aqueous Zinc Ferrite/water (ZnFe₂O₄/water) nanofluids. ZnFe₂O₄/waternanofluids were prepared, suspending hybrid nanoparticles in the basefluids with 0.01 wt% CTAB as surfactant with different weight concentrations i.e., (0.02, 0.05, 0.1, 0.2, 0.5 wt%). Detailed surface properties of ZnFe₂O₄/waternanofluids were characterized using EDS, TEM, and UV–vis spectroscopy. Experiments were conducted to find out the viscosity, thermal conductivity,and convective heat transfer coefficient of ZnFe₂O₄/waternanofluids using laminar flow in a tube geometry using constant heat flux (CHF) boundary condition. Results revealed 11.8% improvement in the thermal conductivity for ZnFe₂O₄/waternanofluids, whereas an enhancement of 42.99% was observed in the convective heat transfer coefficient using 0.5 wt% of the nanofluids.The thermal conductivity results indicate that ZnFe₂O₄/waternanofluids have higher thermal conductivity for all the studied nanofluids. From the experimental data, new correlations for finding the thermophysical properties and Nusselt number has been proposed. The novel correlation established will help scientists and engineers for further insight into future research.