NONLINEAR AMPLITUDE DISPERSION EFFECTS IN EXTREME DEEP-WATER RANDOM WAVES

摘要

The connection between extreme waves and nonlinear group formation is described. A statistical relation is shown, and a physical explanation based on nonlinear dispersion is investigated. Theoretically it can be described by the modified nonlinear Schroedinger equation. Here a simplified theoretical approach is made, in order to interpret laboratory experiments. The results show that the balance between the energy envelope and the instantaneous frequency is essential. Extremes from experiments with random waves show a behaviour similar to effects in bichromatic wave trains.