Numerical study of flow and heat transfer of non-Newtonian Tangent Hyperbolic fluid from a sphere with Biot number effects

In this article, we investigate the nonlinear steady boundary layer flow and heat transfer of an incompressible Tangent Hyperbolic fluid from a sphere. The transformed conservation equations are solved numerically subject to physically appropriate boundary conditions using implicit finite-difference Keller Box technique. The numerical code is validated with previous studies. The influence of a number of emerging non-dimensional parameters, namely Weissenberg number (We), power law index (n), Prandtl number (Pr), Biot number (gamma) and dimensionless tangential coordinate (xi) on velocity and temperature evolution in the boundary layer regime is examined in detail. Furthermore, the effects of these parameters on heat transfer rate and skin friction are also investigated. Validation with earlier Newtonian studies is presented and excellent correlation is achieved. It is found that the velocity, Skin friction and the Nusselt number (heat transfer rate) are decreased with increasing Weissenberg number (We), whereas the temperature is increased. Increasing power law index (n) increases the velocity and the Nusselt number (heat transfer rate) but decreases the temperature and the Skin friction. An increase in the Biot number (gamma) is observed to increase velocity, temperature, local skin friction and Nusselt number. The study is relevant to chemical materials processing applications. (C) 2015 Faculty of Engineering, Alexandria University. Production and hosting by Elsevier B.V.