Nonstationary periodic wave regimes on a falling liquid film

The theoretical and numerical study of the periodic regimes of free flowing liquid film is carried out. As a result of the theoretical analysis, a simple three-harmonic model was obtained. The obtained model allowed demonstrating the basic mechanisms of the periodic flow regime. Calculations on the full model, the Nepomnyashchy equation and three harmonic models are performed. The results of the numerical solutions of the Nepomnyashchy equation and new model qualitatively consistent with the results of the solution of the full model are presented.