Abstract: | Under the assumption that the boundary layer approximation for the original equations is valid, we show the possibility of the existence of progressive waves on the surface of a vertically flowing film when surface tension is neglected. From the system of equations obtained for a thin layer of viscous liquid flowing down an inclined plane, one equation for perturbations of a thin film follows. Steady solutions of this equation allow periodic discontinuous solutions of the roll-wave type.Translated from Zhurnal Prikladnoi Mekhaniki i Teknicheskoi Fiziki, No. 2, pp. 109–113-March–April, 1973. |