Exploring The Synergistic Effects of Alumina-MWCNTS Hybrid Nanofluids in A Closed Conduit Flow: A Performance Analysis

The current work compares the hydrothermal performance of single and hybrid aqua-based nanofluids prepared from Alumina, functionalized MWCNTs (f-MWCNTs), and a nanocomposite of both nanomaterials. In addition to the effect of nanofluid type on thermal performance, the study investigates the effect of flow scheme and highlights the effect of nanofluids heat capacity rate on heat transfer to evaluate the performance of nanofluids in heat transfer applications. The flow under a constant Reynolds number from 10,000 to 20,000 was the first flow scenario in the current study. The second scenario investigated the nanofluids thermal performance under a constant volume flow rate between 3.86 and 7.71 l/min. The heat transfer study for all types of nanofluids was conducted numerically using a CFD model created by the ANSYS-Fluent package, which was validated using experimental data from distilled water (DW) run experiments. All nanofluids concentrations showed a higher Nu number than the DW at the constant Re number scheme, with the highest average enhancement of 10.2% when using 0.1 wt.% Alumina nanofluid. At the constant flow rate scheme, all nanofluids concentrations showed lower Nu number in comparison with the DW. Based on its thermal performance, the results showed the advantage of f-MWCNTs nanofluid over the Alumina and hybrid nanofluid. Moreover, the DW has the highest thermal performance at both flow schemes compared to all nanofluid concentrations. The f-MWCNTs nanofluid of 0.05 wt.% presents the highest performance of 80% in comparison with other nanofluids concentrations.