Numerical simulation of free convection flow and thermal performance comparison between \(Al_2O_3/H_2O\) and \(Al_2O_3/C_2H_6O_2-H_2O\) nanofluids in a rectangular cavity

Alumina nanoparticles have been accumulating attention in recent years because of their unique physical characteristics and broad range of engineering and industrial applications. Scientists are paying close attention to analyzing the flow and heat transfer features of alumina-based nanofluids filled within a cavity due to their wide range of applications, such as heat exchangers, fuel cells, room ventilation, and cooling electronic systems. Motivated by the applications, the current study numerically analyzes the natural convective flow and heat transfer features of \(Al_2O_3-H_2O\) $A{l}_2{O}_3-H_{2}O$ and \(Al_2O_3/C_2H_6O_2-H_2O\) $A{l}_2{O}_3/C_2{H}_6{O}_2-H_{2}O$ nanofluids in a rectangular porous cavity under the presence of thermal radiation and heat generation/absorption by using the non-Fourier heat flux model. The system of equations is numerically solved by utilizing the Marker and Cell technique. The comparative fluid flow and heat transfer features are performed by using different shapes of \(Al_2O_3\) $A{l}_2{O}_3$ nanoparticles (spherical, brick, cylindrical, platelet, and blade) dispersed in two different kinds of base fluids ( \(H_2O\) $H_{2}O$ and \(C_2H_6O_2-H_2O\) $C_2{H}_6{O}_2-H_{2}O$ ). The flow domain is filled with an isotropic porous medium. Several pertinent parameters are considered in this investigation, such as the Darcy number, Rayleigh number, heat source/sink, radiation parameter, and nanoparticle volume fractions, which are analyzed in terms of streamlines, isotherms, and local and average Nusselt numbers. According to the findings, the average Nusselt number increases by augmenting the nanoparticle volume concentration and the heat source/sink parameters, while it decreases by improving the radiation influence. Thermal performance within the cavity is affected by varying radiation influences. By increasing the spherical-shaped \(Al_2O_3\) $A{l}_2{O}_3$ nanoparticle concentration from 0 to 5% in \(H_2O\) $H_{2}O$ and \(C_2H_6O_2-H_2O\) $C_2{H}_6{O}_2-H_{2}O$ base fluids, the average heat transfer rate is augmented by 27.37% and 27.62%, respectively. The blade-shaped nanoparticles produce a better heat transfer rate than other-shaped nanoparticles. Finally, it was concluded that \(Al_2O_3-H_2O\) $A{l}_2{O}_3-H_{2}O$ nanofluid delivers better fluid flow and temperature distribution than \(Al_2O_3/C_2H_6O_2-H_2O\) $A{l}_2{O}_3/C_2{H}_6{O}_2-H_{2}O$ nanofluid.