Investigation of MHD nanofluid flow and heat transfer in a stretching/shrinking convergent/divergent channel considering thermal radiation

In this paper, heat transfer of a steady, viscous incompressible water based MHD nanofluid flow from a source or sink between two stretchable or shrinkable walls with thermal radiation effect is investigated. A similarity transformation is used to convert the governing radial momentum and energy equations into nonlinear ordinary differential equations with the appropriate boundary conditions. These nonlinear ordinary differential equations are solved analytically by Duan-Bach Approach (DRA), This method allows us to find a solution without using numerical methods to evaluate the undetermined coefficients. This method modifies the standard Adomian Decomposition Method (ADM) by evaluating the inverse operators at the boundary conditions directly. The approximate analytical investigation is carried out for different values of the embedding parameters, namely: stretching/shrinking parameter, radiation parameter, Reynolds number, Hartmann number, opening angle and solid volume fraction. The results show that the fluid velocity and temperature distribution increase with the increasing of stretching parameter. The results were also compared with numerical solution in order to verify the accuracy of the proposed method. It has been seen that the current results in comparison with the numerical ones are in excellent agreement. (C) 2016 Elsevier B.V. All rights reserved.