Investigation of the Structure of Waves Generated by a $\delta$-perturbation of the Surface of a Capillary Jet

The wave capillary flow of the surface of an inviscid capillary jet, initiated by a single $\delta$-perturbation of its surface, is studied. It is shown that the wave pattern has a complex structure. The perturbation generates both fast traveling damped waves and a structure of nonpropagating exponentially growing waves. The structure of self-similar traveling waves is investigated. It is shown that there are three independent families of such self-similar solutions. The characteristics of the structure of nonpropagating exponentially growing waves are calculated. The characteristic time of formation of such a structure is determined.