Slip Flow and Heat Transfer of Nanofluids over a Porous Plate Embedded in a Porous Medium with Temperature Dependent Viscosity and Thermal Conductivity

Taha Aziz,Chaudry Khalique,Sajid Hussain,Asim Aziz

doi:10.3390/app6120376

Taha Aziz, Chaudry Khalique + Show 2 more

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https://doi.org/10.3390/app6120376

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Abstract

It is well known that the best way of convective heat transfer is the flow of nanofluids through a porous medium. In this regard, a mathematical model is presented to study the effects of variable viscosity, thermal conductivity and slip conditions on the steady flow and heat transfer of nanofluids over a porous plate embedded in a porous medium. The nanofluid viscosity and thermal conductivity are assumed to be linear functions of temperature, and the wall slip conditions are employed in terms of shear stress. The similarity transformation technique is used to reduce the governing system of partial differential equations to a system of nonlinear ordinary differential equations (ODEs). The resulting system of ODEs is then solved numerically using the shooting technique. The numerical values obtained for the velocity and temperature profiles, skin friction coefficient and Nusselt’s number are presented and discussed through graphs and tables. It is shown that the increase in the permeability of the porous medium, the viscosity of the nanofluid and the velocity slip parameter decrease the momentum and thermal boundary layer thickness and eventually increase the rate of heat transfer.

Highlights

The heat transfer due to fluid flow is an important factor in problems in industries, such as heat exchangers, the recovery of petroleum resources, fault zones, catalytic reactors, cooling systems, electronic equipment manufacturing, etc
The computations are performed to study the effects of the variation of permeability parameter k∗, nanofluid volume concentration parameter φ, velocity slip parameter δ, thermal slip parameter ∆, suction and injection parameter S, viscosity parameter A and variable thermal conductivity e on the velocity and temperature profiles of the Cu-water nanofluid
The viscosity and the thermal conductivity of the nanofluids were considered as linear functions of temperature, and wall slip conditions were employed in terms of shear stress

Summary

Introduction

The heat transfer due to fluid flow is an important factor in problems in industries, such as heat exchangers, the recovery of petroleum resources, fault zones, catalytic reactors, cooling systems, electronic equipment manufacturing, etc. The heat transfer characteristics in the boundary layer are influenced by a number of factors, including flow geometry, the viscosity of a fluid, thermal conductivity, bounding surface characteristics, boundary conditions, flow medium and the orientation and intensity of the applied magnetic field [1,2,3]. Maxwell first proposed that the thermal conductivity of the fluid can be increased by including solid particles in the flow domain [4]. Following Maxwell, extensive research has been conducted to study the heat transfer characteristics of fluid flow in a porous medium. It is beyond the scope of this work to revisit the vast amount of literature on.

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