Analytical investigation of the micropolar flow through a porous channel with changing walls

In this paper, two-dimensional micropolar flow in a porous channel with expanding or contracting walls is considered. Then a similarity transformation is used to reduce the problem by a set of nonlinear boundary value problems. This problem is studied by a new hybrid technique based on differential transform method (DTM) and iterative Newton's method (INM). In this solution, there is no need to restrictive assumptions or linearization. Also a numerical solution is done to validate the present analytical method. The approximate solutions for the axial velocity, normal velocity and microrotation are obtained by the proposed technique. The results are presented to study the velocity and rotation profiles for various physical parameters such as: permeability Reynolds number, rotation parameter, boundary parameter and expanding (or contracting) ratio. As an important result, the profiles of the streamwise velocity and microrotation are asymmetric, while the normal velocity is symmetric.