Transient MHD Mixed Double Diffusive Convection Along a Vertical Plate Embedded in a Non-Darcy Porous Medium with Suction or Injection

Paulo Paulo

doi:10.3844/jmssp.2012.15.23

Abstract

Problem statement: Transient non-Darcy mixed double convection from a semi-infinite, isothermal vertical plate embedded in a homogeneous porous medium, in the presence of surface suction or injection had been numerically investigated. Approach: Forchheimer extension was considered in the flow equations. Appropriate transformations were employed to transform the derived partial differential equations governing the problem under consideration on the assumption of a small magnetic Reynolds number into a system of non linear ordinary differential equations, which were integrated by the fourth-order Runge-Kutta method. Results: Numerical results illustrating the effects of all involved parameters on the transient velocity, temperature and concentration profiles, the local Nussle, the local Sherwood numbers and the local skin fiction coefficient, were presented and discussed. The results were compared with those known from literature. Conclusion: Velocity and temperature increase due to the increasing of the parameters involved in the problem, while the increasing in the solutal dispersion parameter decreases the mass transfer coefficint.

Highlights

Convection in porous media have been based on Darcy's law which is applicable for slow flows and does not Convection heat transfer and flow through porous account for non-Darcian inertial effects
Nield and medium is phenomenon of great interest from both Bejan (2006) have made a comprehensive review of the theoretical and practical point of view. This is because growing volume of study devoted to heat transfer and of its important applications in several geophysical, flow through porous medium
Analyzed the problem of flow heat and mass transfer of laminar, incompressible and electrically conducting fluid over a semi-infinite vertical plate embedded in a porous medium with surface suction

Summary

Introduction

Convection in porous media have been based on Darcy's law which is applicable for slow flows and does not Convection heat transfer and flow through porous account for non-Darcian inertial effects. Aboeldabab and Elbarbary (2001) involve unsteadiness and examples of transient studied the Hall current effects on MHD free-convection convective flows are numerous, for example, cooling of flow past a semi-infinite vertical plate with mass transfer. Analyzed the problem of flow heat and mass transfer of laminar, incompressible and electrically conducting fluid over a semi-infinite vertical plate embedded in a porous medium with surface suction. It is assumed that the fluid properties are constant except the influence of density variation with temperature, which is considered only in the body force term of the momentum equation Both the fluid and solid matrix transient free convection from suddenly cooled are assumed to be in local thermal equilibrium. Eq 1-4 are given by: Harris et al (1996; 1997) and Ingham et al (1982)

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Conclusion