Non-Darcy Natural Convection From a Vertical Cylinder Embedded in a Thermally Stratified and Nanofluid-Saturated Porous Media

Abstract

In recent years, nanofluids have attracted attention as a new generation of heat transfer fluids in building heating, heat exchangers, plants, and automotive cooling applications because of their excellent thermal peiformance. Various benefits of the application of nanofluids include improved heat transfer, heat transfer system size reduction, minimal clogging, microchannel cooling, and miniaturization of systems. In this paper, a study of steady, laminar, natural convection boundary-layer flow adjacent to a vertical cylinder embedded in a thermally stratified nanofluid-saturated non-Darcy porous medium is investigated. The model used for the nanofluid incorporates the effects of Brownian motion and thermophoresis, and a generalized porous media model, which includes inertia and boundary effects, is employed. The cylinder surface is maintained at a constant nanoparticles volume fraction, and the wall temperature is assumed to vary with the vertical distance according to the power law form. The resulting governing equations are nondimensionalized and transformed into a nonsimilar form and then solved by Keller box method. A comparison is made with the available results in the literature, and our results are in very good agreement with the known results. A parametric study of the physical parameters is made, and a representative set of numerical results for the velocity, temperature, and volume fraction, as well as local shear stress and local Nusselt and Sherwood numbers, are presented graphically. The salient features of the results are analyzed and discussed. The results indicate that, when the buoyancy ratio or modified Grashof number increases, all of the local shear stress, local Nusselt number, and the local Sherwood number enhance while the opposite behaviors are predicted when the thermophoresis parameter increases. Moreover, increasing the value of the surface curvature parameter leads to increases in all of the local shear stress and the local Nusselt and Sherwood numbers while the opposite behaviors are obtained when either of the thermal stratification parameter or the boundary effect parameter increases.

Heat transport on steady MHD flow of copper and alumina nanofluids past a stretching porous surface

“…EL‐Kabeir et al discussed an unsteady, three‐dimensional (3D), laminar, boundary‐layer flow of a viscous, incompressible, and electrically conducting fluid over an inclined permeable surface embedded in a porous medium in the presence of a uniform magnetic field and heat generation/absorption effects. Rashad et al investigated a steady, laminar, natural convection boundary‐layer flow adjacent to a vertical cylinder embedded in a thermally stratified nanofluid‐saturated non‐Darcy porous medium. Chamkha et al considered unsteady, laminar, boundary‐layer flow with heat and mass transfer of a nanofluid along a horizontal stretching plate in the presence of a transverse magnetic field, melting and heat generation or absorption effects.…”

Effects of Variable Viscosity on Heat and Mass Transfer by MHD Mixed Convection Flow Along a Vertical Cylinder Embedded in a Non-Darcy Porous Medium

“…Furthermore, the fluid solid matrix are assumed to be in local thermal non-equilibrium, thus, two models of temperature for heat transfer is applied. Rashad et al, (2014) presented a study to investigate the free convection flow along a vertical cylinder embedded in a thermally stratified nanofluid-saturated non-Darcy porous medium. In the presence of thermal radiation a numerical solution of transient free convection MHD flow over a vertical cylinder of thermal and mass diffusion was presented by Reddy (2014).…”

Numerical Research of Hall Current Influence on MHD Convective “Flow in Presence” of Jeffrey Fluid, “Heat and Mass Transfer”

“…Prabhakar-Reddy also Anand-Rao [4] demonstrated the influence of radioactivity also heat on MHD free-standing channels passing through an infinite wall plate with Hall current and heat source. Rashad et al [5] performed a study of a unique stationary tube located on a solid line with a vertical cylinder mounted in a non-Darcy Nano fluid-saturated filter. Rashidi_et_al.…”