Mixed convection flow of micropolar fluid over an isothermal plate with variable spin gradient viscosity
This paper considers steady two-dimensional mixed convection of a viscous incompressible micropolar fluid past an isothermal horizontal heated plate in a uniform free stream with variable spin gradient viscosity. By introducing a local buoyancy parameter defined as \(\xi=Gr_x/Re_x^{5/2}\), where \(Gr_x\) is the local Grashof number and \(Re_x\) is the local Reynolds number, the authors transform the boundary layer equations into a non-similar form. these equations are able to describe both forced convection dominated flow and free convection dominated flow in limiting cases when \(\xi\to 0\) and \(\xi\to\infty\), respectively. Solutions to these transformed equations are obtained using an implicit finite difference method known as Keller box scheme. Three flow regimes are studied, namely, forced, free and mixed convection regimes. Numerical computations are carried out for fluid having a Prandtl number of 0.7 (air at \(20^\circ C)\) over the entire regimes mentioned above with the vortex viscosity parameter \(\Delta=0.0\), 1.0, 5.0 and 10.0. The authors present in tables and graphs numerical results for reduced skin friction, reduced heat transfer rates, velocity profiles and couple-stress. A detailed discussion of these flow characteristics is given, and it is shown that the local skin friction increases and the local heat transfer rate decreases with an increase in \(\Delta\) at any value of Prandtl number. It is also shown that both the momentum boundary layer and thermal boundary layer increase due to the increase in \(\Delta\).
scientific article; zbMATH DE number 1270079
scientific article