Three-dimensional solitary waves on falling liquid film at low Reynolds numbers

In this Letter we present novel results of the experimental study of three-dimensional waves evolving from a localized disturbance on a vertically falling film at low Reynolds numbers 1.25 < Re < 4.7. This range of Re is close to the values that are typical for residual layers in developed wavy film flow with moderate Reynolds numbers. A spatiotemporal evolution of three-dimensional solitary waves is investigated. Existence of the stationary horseshoe-shaped waves has been demonstrated. The measured wave characteristics are compared with the theoretical solutions.