ISSN オンライン: 2688-7231
ISBN 印刷: 978-1-56700-497-7 (Flash Drive)
ISBN オンライン: 978-1-56700-496-0
Proceedings of the 25th National and 3rd International ISHMT-ASTFE Heat and Mass Transfer Conference (IHMTC-2019)
Heat transfer characteristic of free hybrid nanofluid jet on the structured surface
The higher local heat transfer coefficient makes liquid jet impingement promising techniques to extract high heat flux (cooling) in various industrial process. This cooling process attributed to higher heat transfer capabilities of the fluid and surface properties of the target. The effective combination of the both the parameters would augmented the heat flux. In the present investigation, the thermal properties of fluid enhanced by the addition of novel Ag/ZnO hybrid nanoparticles in water (nanofluid) at different volume concentration ranges form (φ = 0.06 and 0.10%) and the surface properties of the targeted plate was modified by different structure configuration (zig-zag, inline and squared) to enhance the heat transfer area. The novel synthesis method of hybrid nanoparticles promotes uniform coating of the Ag ions on the ZnO which leads to enhancement in the thermal conductivity with stability. The experiments were conducted by impinging free circular jet on a 90 mm diameter and 3mm copper plate. A parametric study was performed to investigate the effect of Reynolds number (Re = 3130-6720) and plate to nozzle distance ratio (H/D = 2 to 6) on the heat transfer characteristic. The experimental results shows that enhanced structures rather than bare surface increases the wetted area. The enhanced wetted area increase the residence time of the fluid and plays decisive factor for enhancing the cooling performance. The enhancement in the heat transfer coefficient in case of zigzag surface is more than others. Furthermore, increase nucleation sites yielded the heat transfer performance in the structured surface. The hybrid nanofluid with higher thermal conductivity (φ= 0.1%) shows higher cooling rate compared to other concentrations.