Mixed convection heat transfer from a horizontal plate to non-Newtonian fluids

Abstract

Steady laminar mixed convection of non-newtonian fluids over a horizontal plate has been analyzed. After a suitable coordinate transformation to reduce the complexity of the governing boundary-layer equations, the resulting nonlinear coupled differential equations were solved with an implicit finite difference scheme. Of particular interest are the effects of the power-law viscosity index, the generalized Prandtl number and the buoyancy parameter on fluid flow and heat transfer characteristics. It was found that both the dimensionless skin friction group and the dimensionless heat transfer group increase with higher buoyancy effects for any non-Newtonian fluid. Dilatant fluids exhibit a distinctively different behavior with respect to dimensionless heat transfer group when compares to pseudoplastics in the leading edge of the flat plate. Furthermore, higher generalized Prandtl numbers generate lower skin friction and larger heat transfer coefficients.