Hybrid Water-Based Suspension of Al2O3 and Cu Nanoparticles on Laminar Convection Effectiveness

A numerical investigation of a laminar forced convection of different working fluids including pure water, various volume concentrations of a nanofluid (Al2O3 nanoparticles dispersed in water), and a hybrid water-based suspension of Al2O3 and Cu nanoparticles (which is a new advanced nanofluid with two kinds of nanoparticle materials) in a uniformly heated circular tube is accomplished. In this paper, the effect of using hybrid water-based suspension on thermal behavior and hydrodynamic performance in a range of Reynolds number in the laminar regime is investigated. Then, a comparison is made between the thermal and hydrodynamics behavior of the hybrid suspension with those of the nanofluid (with the same concentration) and the conventional one. It is observed that, for all Reynolds numbers studied, employing the hybrid suspension improves the heat transfer rate compared to pure water and the nanofluid. Nevertheless, it reveals an adverse effect on the wall shear stress and friction factor due to the presence of nanoparticles. However, the average increase of overall Nusselt number (rather to pure water) in hybrid suspension is 7.20%, whereas is is 10.94% for the average increase of the friction factor.