Breaking of Faraday Waves and Jet Launch Formation

Irregular and breaking Faraday waves are experimentally investigated. Among the irregular waves those with a small depression in the wave crest and periodic triplets are distinguished. In the case of breaking waves the mechanism of jet launch formation on the wave crest is considered. It is experimentally demonstrated that the breaking of standing waves in a rectangular reservoir starts with cavity collapse on the wave crest in process of formation. It is shown that Jet launch from the wave crest is preceded by the initiation, development, and collapse of a cavity. A universal power-law dependence governing cavity collapse is obtained. A comparison of the experimental data with an analytical model suggests that cavity initiation is due to the nonlinearity of the waves themselves, namely, the presence of two small disturbances of the free surface traveling counter to one another and forming a cavity. The results obtained underline the importance of the initial stage of wave breaking.