Numerical Investigation of Entropy Generation in Unsteady MHD Generalized Couette Flow with Variable Electrical Conductivity

T Chinyoka,O D Makinde

doi:10.1155/2013/364695

Abstract

The thermodynamic second law analysis is utilized to investigate the inherent irreversibility in an unsteady hydromagnetic generalized Couette flow with variable electrical conductivity in the presence of induced electric field. Based on some simplified assumption, the model nonlinear governing equations are obtained and solved numerically using semidiscretization finite difference techniques. Effects of various thermophysical parameters on the fluid velocity, temperature, current density, skin friction, the Nusselt number, entropy generation number, and the Bejan number are presented graphically and discussed quantitatively.

Highlights

Investigation of the flow of electrically conducting fluids in porous geometries is of particular importance due to the widespread prevalence in a number of industrial applications [1,2,3,4]
The entropy production resulting from combined effects of velocity and temperature gradients has remained untreated by classical thermodynamics, which has motivated many researchers to conduct analyses of fundamental and applied engineering problems based on the second law analyses
Entropy generation is associated with thermodynamic irreversibility, which is common in all types of heat transfer processes, namely, conduction, convection, and radiation

Summary

Introduction

Investigation of the flow of electrically conducting fluids in porous geometries is of particular importance due to the widespread prevalence in a number of industrial applications [1,2,3,4]. These include applications to geothermal reservoirs, nuclear reactor cooling, Magnetohydrodynamic (MHD) marine propulsion, electronic packaging, microelectronic device operations, thermal insulation, and petroleum reservoirs. The entropy production resulting from combined effects of velocity and temperature gradients has remained untreated by classical thermodynamics, which has motivated many researchers to conduct analyses of fundamental and applied engineering problems based on the second law analyses. The fundamental principle remains the improvement of the relevant thermal systems to mitigate against energy losses and fully optimize the energy resources

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Results

Conclusion