Comparative heat transfer analysis of γ - A l 2 O 3 - C 2 H 6 O 2 and γ - 2 O 3 - H 2 O electroconductive nanofluids in a saturated porous square cavity with Joule dissipation and heat source/sink effects

Inspired by the applications in electromagnetic nanomaterials processing in enclosures and hybrid fuel cell technologies, a mathematical model is presented to analyze the mixed convective flow of electrically conducting nanofluids (γ- A l 2 O 3 - H 2 O and γ- A l 2 O 3 - C 2 H 6 O 2) inside a square enclosure saturated with porous medium under an inclined magnetic field. The Tiwari-Das model, along with the viscosity, thermal conductivity, and effective Prandtl number correlations, is considered in this study. The impacts of Joule heating, viscous dissipation, and internal heat absorption/generation are taken into consideration. Strongly nonlinear conservation equations, which govern the heat transfer and momentum inside the cavity with associated initial and boundary conditions, are rendered dimensionless with appropriate transformations. The marker-and-cell technique is deployed to solve the non-dimensional initial-boundary value problem. Validations with a previous study are included. A detailed parametric study is carried out to evaluate the influences of the emerging parameters on the transport phenomena. When 5 % γ- A l 2 O 3 nanoparticles are suspended into H 2 O base-fluid, the average heat transfer rate of γ- A l 2 O 3 - H 2 O nanoliquid is increased by 25.63 % compared with the case where nanoparticles are absent. When 5 % γ- A l 2 O 3 nanoparticles are suspended into C 2 H 6 O 2 base-fluid, the average heat transfer rate of γ- A l 2 O 3 - C 2 H 6 O 2 nanofluid is increased by 43.20 % compared with the case where nanoparticles are absent. Furthermore, when the heat source is present, the average heat transfer rate of γ- A l 2 O 3 - C 2 H 6 O 2 nanofluid is 194.92 % higher than that in the case of γ- A l 2 O 3 - H 2 O nanofluid.