THE EFFECT OF VARIABLE VISCOSITY ON MHD NATURAL CONVECTION IN MICROPOLAR FLUIDS

The influence of variable viscosity and a transverse magnetic field on natural convection in micropolar fluids is examined. The fluid viscosity is assumed to vary as an inverse linear function of temperature. Four different vertical flows have been analyzed, those adjacent to an isothermal surface and uniform heat flux surface, a plane plume and flow generated from a horizontal line energy source on a vertical adiabatic surface, or wall plume. By means of similarity solutions and deviation of the velocity, temperature and micro-rotation fields as well as the skin friction, heat transfer and wall couple stress results from their constant values are determined. Key words: natural convection, micropolar fluids, variable viscosity. 1