Comparative heat transfer analysis of <b> <i>γ</i> </b>-Al2O3−C2H6O2 and <b> <i>γ</i> </b>-Al2O3−H2O electroconductive nanofluids in a saturated porous square cavity with Joule dissipation and heat source/sink effects

Abstract

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-Al2O3−H2O and γ-Al2O3−C2H6O2) 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-Al2O3 nanoparticles are suspended into H2O base-fluid, the average heat transfer rate of γ-Al2O3−H2O nanoliquid is increased by 25.63% compared with the case where nanoparticles are absent. When 5% γ-Al2O3 nanoparticles are suspended into C2H6O2 base-fluid, the average heat transfer rate of γ-Al2O3−C2H6O2 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-Al2O3−C2H6O2 nanofluid is 194.92% higher than that in the case of γ-Al2O3−H2O nanofluid.