非线性聚焦生成畸形波规律之研究

Investigation of freak wave generation via nonlinear focusing

非线性聚焦是畸形波生成的一种可能机理。采用可以描述非线性聚焦现象的四阶修正非线性薛定谔方程,模拟了边带扰动条件下波列空间演化过程中畸形波的生成。不同初始边带扰动条件和不同波陡等情况下的数值试验结果表明,满足边带不稳定性条件时,初始边带扰动条件和波陡对畸形波的生成具有重要的影响,并给出了畸形波生成的规律。

A possible mechanism of freak wave generation is nonlinearity focusing.Generation of freak waves under the condition of sideband disturbance was numerically simulated within the framework of the modified fourth-order nonlinear Schroedinger equation which can describe nonlinear focusing phenomenon.Numerical experiments were performed for different sideband disturbances and wave steepness.Results show that initial sideband disturbances and wave steepness play an important role in the formation of freak waves when sideband instability is satisfied.And generation rules of freak waves under sideband disturbance condition are also given.