Laboratory and numerical study of intense envelope solitons of water waves: Generation, reflection from a wall, and collisions

Abstract

The investigation of dynamics of intense solitary wave groups of collinear surface waves is performed by means of numerical simulations of the Euler equations and laboratory experiments. The processes of solitary wave generation, reflection from a wall, and collisions are considered. Steep solitary wave groups with characteristic steepness up to kAcr ≈ 0.3 (where k is the dominant wavenumber and Acr is the crest amplitude) are concerned. They approximately restore the structure after the interactions. In the course of the interaction with the wall and collisions, the maximum amplitude of the wave crests is shown to enhance up to 2.5 times. A standing-wave-like structure occurs in the vicinity of the wall, with certain locations of nodes and antinodes regardless the particular phase of the reflecting wave group. A strong asymmetry of the maximal wave groups due to an anomalous setup is shown in situations of collisions of solitons with different frequencies of the carrier. In some situations of head-on collisions, the amplitude of the highest wave is larger than in overtaking collisions of the same solitons. The discovered effects in interactions of intense wave groups are important in the context of mechanisms and manifestations of oceanic rogue waves.