Abstract
This paper develops a mathematical model with an aim to compute the analytic solution for the flow of a fourth grade fluid between two fixed porous walls. The flow is induced under the application of a constant pressure gradient. The arising nonlinear problem is treated analytically yielding a series solution by homotopy analysis method (HAM). Results of velocity and shear stresses at the walls are obtained. The impacts of several flow parameters are examined on the velocity and shear stresses.