Analysis of Heat Transfer inside Rectangular Micro-Channel with Wavy Surface and Hybrid Nanofluids

The current work aims to numerically investigate the impact of using (50% ZnO and 50% Al₂O₃) hybrid nanofluid (HNf) on the performance of convective heat transfer inside a horizontal wavy micro-channel. This issue represents a novel approach that has not been extensively covered in previous research and provides more valuable insights into the performance of HNfs in complex flow geometries. The conjugate heat transfer approach is used to demonstrate the influence of adding hybrid nanoparticles (50% Al₂O₃ and 50% ZnO) to pure water on the rate of heat transfer. The governing equations are numerically solved by using ANSYS FLUENT (2021 R2). The behaviors of convective heat transfer coefficient (HTC), Nusselt number (Nu) and pressure drop are presented under various volume concentrations of (1%, 2% and 3%) and Reynolds numbers (Re = 600, 1200 and 1800). The numerical results are validated against the experimental one, where the validation test shows a good agreement between them. The findings display that the highest HTC enhancement is reached at 59.5% when using a volume concentration of 3% and Re = 1800. The Nusselt number is increased with the rise in volume concentration of nanoparticles, where the value of the Nusselt number is improved by 42.25% at 3% volume concentration. The reduction in pressure is raised with an increase in volume concentration and $Re$. The results also show that the combination of dispersion characteristics, Brownian movement and nanoparticles leads to an improvement in the rate of heat transfer. It is concluded that $\text{Nu}$ and the behavior of heat transfer are considerably enhanced when using a hybrid nanofluid inside a wavy micro-channel.