Effects of variable viscosity and thermal conductivity on magnetohydrodynamic free convection flow of a micropolar fluid past a stretching plate through porous medium with radiation, heat generation, and Joule dissipation

The effects of temperature-dependent viscosity and thermal conductivity on free convection magnetohydro- dynamic ow of an optically thin gray, viscous, and incompressible micropolar uid and heat transfer past a stretching plate through porous medium in the presence of radiation, heat generation, and Joule dissipation were studied. The uid viscosity and thermal conductivity were assumed to vary as inverse linear functions of temperature. Using similarity transformation, the governing partial differential equations of motion were reduced to ordinary ones, which were solved numerically for prescribed boundary conditions using the shooting method. Numerical results for the velocity, angular velocity, and temperature proles are shown graphically and the skin friction and Nusselt number are presented in tab- ular form for various values of the parameters, giving the ow and heat transfer characteristics. We found that viscosity enhanced microrotation, while an increase in thermal conductivity reduced the temperature.