Effects of Variable Viscosity and Thermal Conductivity of Unsteady Mixed Convection Flow at the Stagnation Point and an Applied Magnetic Field

Abstract

In this paper the effects of variable viscosity and variable
thermal conductivity of unsteady laminar incompressible mixed convection
flow of an electrically conducting fluid at the stagnation of a twodimensional
body and an axi-symmetric body in the presence of applied
magnetic field is investigated. Both prescribed wall temperature and
prescribed heat flux condition have been considered. The problem was
studied under the effects of variable viscosity, and variable thermal
conductivity. Using a similarity transformation, the governing
fundamental equations are approximated by a system of nonlinear
ordinary differential equations. The resultant system of ordinary
differential equations is then solved numerically using Runge-Kutta
Shooting method with guessed initial conditions. Details of the velocity and
temperature fields as well as the local skin friction and the local Nusselt
number for various values of the parameters of the problem are presented.
The results presented, demonstrate quite clearly that Ge and Gr, which are
indicator of the variation of viscosity and thermal conductivity with
temperature have a substantial effect on the drag and heat transfer
characteristics as well as the velocity and temperature distributions within
the boundary layer.