Effects of variable viscosity and thermal conductivity on magnetohydrodynamicfree convection ow of a micropolar uid past a stretching plate through porousmedium with radiation, heat generation, and Joule dissipation

Abstract

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 stretchingplate through porous medium in the presence of radiation, heat generation, and Joule dissipation were studied. The uidviscosity and thermal conductivity were assumed to vary as inverse linear functions of temperature. Using similaritytransformation, the governing partial differential equations of motion were reduced to ordinary ones, which were solvednumerically for prescribed boundary conditions using the shooting method. Numerical results for the velocity, angularvelocity, and temperature pro les 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 viscosityenhanced microrotation, while an increase in thermal conductivity reduced the temperature.