This project presents a nonlinear stability analysis of thin viscoelastic liquid films flowing down a plate moving in a vertical direction. The long-wave perturbation method is employed to derive the generalized kinematic equations for a free film interface. The elaborated nonlinear film flow model is solved by the method of multiple scales. The modeling results clearly indicate that both subcritical instability and supercritical stability conditions are possibly to occur in the film flow system. The effect of the down-moving motion of the vertical plate tends to enhance the stability of the film flow.
