MHD MIXED CONVECTION OF A VISCOUS DISSIPATION FLUID ABOUT A VERTICAL FLAT PLATE WITH UNIFORM SUCTION AND INJECTION

摘要

A genuine variational principle developed by Gyarmati, in the field of thermodynamics of irreversible processes unifying the theoretical requirements of technical, environmental and biological sciences, is employed to study the thermodynamical effects of viscous dissipation in laminar magnetohydrodynamic (MHD) mixed convection flow over a vertical flat plate with uniform suction and injection. The velocity and temperature distributions inside the boundary layer have been considered as a simple polynomial function and the principle is formulated. The Euler-Lagrange equations are reduced to coupled polynomial equations in terms of boundary layer thicknesses. The velocity and temperature profiles as well as the skin friction and local heat transfer parameters are determined for different values of the governing parameters, mainly the buoyancy parameter (K), the magnetic parameter (ζ), the Prandtl number (Pr), the Eckert number (E_c) and suction/injection parameter (H). For some specific values of the governing parameters, the results agree very well with those available in the literature. The present study establishes a high accuracy of results obtained by this variational technique.