Mixed Convection Boundary Layer Flow from a Horizontal Circular Cylinder in a Micropolar Fluid: Case of Constant Wall Heat Flux

摘要

The laminar mixed convection boundary layer flow of an incompressible micropolar fluid past a horizontal circular cylinder with a constant surface heat flux q{sub}w, has been studied in both cases of a heated and cooled cylinder. The transformed conservation equations of the non-similar boundary layers are solved numerically using a very efficient finite-difference method known as the Keller-box scheme. The solutions' for the flow and heat transfer characteristics are evaluated numerically for different parameters, such as the mixed convection parameter A, the material parameter K (vortex viscosity parameter) and the Prandtl number Pr. It is found that heating the cylinder delays separation of the boundary layer and can, if the cylinder is warm enough, suppress it completely. Cooling the cylinder, on the other side, brings the separation point nearer to the lower stagnation point and for sufficiently cold cylinder there will not be a boundary layer on the cylinder.