Homotopy perturbation method for thin film flow and heat transfer over an unsteady stretching sheet with internal heating and variable heat flux

We have analyzed the effects of variable heat flux and internal heat generation on the flow and heat transfer in a thin film on a horizontal sheet in the presence of thermal radiation. similarity transformations are used to transform the governing equations to a set of coupled nonlinear ordinary differential equations. the obtained differential equations are solved approximately by the homotopy perturbation method (hpm). the effects of various parameters governing the flow and heat transfer in this study are discussed and presented graphically. comparison of numerical results is made with the earlier published results under limiting cases. © 2012 i-chung liu and ahmed m. megahed.