Numerical Investigation of Laminar Forced Convection Heat Transfer Nanofluids Flow Using Different Base Fluids

In this paper, Numerical investigation of laminar forced convection heat transfer nanofluids flow through a horizontal circular pipe under a constant heat flux using different base fluids. In the first part, it has been studied the effect of using several base fluids such as water, engine oil and mercury at different temperature ranging from 280 to 320 K and at different Reynolds number values ranging from 100 to 2100 on average Nusselt number and pressure drop. In the second part, it has been studied the effect of suspended of Al2O3 at 3% volume fraction, 295 K and Reynolds number equal 1460 on heat transfer coefficient and local Nusselt number. The governing equations have been modeled using finite volume method approach with SIMPLE algorithm helping with ANSYS FLUENT software. The results indicate that the average Nusselt number and pressure drop for all base fluids increase as Reynolds number increase and decrease as temperature decrease. Engine oil has a higher average Nusselt number and pressure drop while mercury has a small average Nusselt number and pressure drop. Also, mercury has a small change with temperature. Moreover, average Nusselt number is only function of Prandtl and Reynolds number but pressure drop varies with Reynolds number. Add of Al2O3 nanoparticle to the base fluids enhanced the heat transfer coefficient and local Nusselt number for all nanofluids. It has been found that mercury has a higher heat transfer coefficient and small Nusselt number due to higher thermal conductivity and small thermal boundary layer thickness.