New Model for Waves in a Falling Film

The new model is developed for long-wave perturbations in a falling liquid film. The model is based on the boundary-layer approach and expansion of velocity into the system of linearly independent basic functions (harmonics), which satisfies boundary conditions. The linear analysis of stability and numerical simulations of nonlinear waves are carried out. Results of calculations of dispersion relations and modelling nonlinear waves on the basis of presented model coincide well with avail- able experimental data.