Unsteady flow of a second grade fluid film over an unsteady stretching sheet

In this article, the flow problem in a thin liquid film of second grade fluid over an unsteady stretching surface is investigated. By means of suitable transformations, the governing nonlinear partial differential equation has been reduced to the nonlinear ordinary differential equation. The developed nonlinear equation is solved analytically by using the homotopy analysis method (HAM). An expression for analytic solution is derived in the form of a series. The convergence of the obtained series is shown explicitly through numerical computations. The effects of various parameters on the velocity components are shown through graphs and discussed. The values of the skin-friction coefficient for different emerging parameters are also tabulated. c © 2007 Elsevier Ltd. All rights reserved.