MIXED CONVECTION IN MICROPOLAR BOUNDARY-LAYER FLOW OVER A HORIZONTAL SEMIINFINITE PLATE

A boundary layer analysis is presented to study the effects of buoyanc y-induced streamwise pressure gradients on laminar forced convection h eat transfer to micropolar fluids from a horizontal semi-infinite flat plate. The transformed boundary-layer equations have been solved nume rically. The effects of the buoyancy force, material parameters, and v iscous dissipative heat on the friction factor, total heat transfer, d isplacement thickness, and wall couple stress, as well as the details of the velocity, microrotation, and temperature fields are discussed. A comparison has been made with the corresponding results for Newtonia n fluids. Micropolar fluids display drag reduction and reduced heat tr ansfer rate as compared with Newtonian fluids. Also the micropolar pro perties of the fluid are found to play an important role in controllin g flow separation. Furthermore, it is observed that, for high values o f the buoyancy and material parameters, the flow and thermal fields ar e significantly affected by the presence of viscous dissipation heal.