Abstract
The assumption that a fluid adheres to a solid boundary ('no-slip' boundary condition) is one of the central tenets of the Navier-Stokes theory. However, there are situations wherein this assumption does not hold. In this communication we examine the effects of slip at the wall when an Oldroyd 6-constant fluid is considered in a channel. The slip assumed depends on the shear stress at the wall. The three non-linear problems are solved using homotopy analysis method (HAM). The results for the velocity profiles are presented and discussed.