波群内单个波的波陡分布与波破碎

The steepness distributions and break of individual waves in wave groups

对波群内单个波的波陡分布和波破碎进行了实验研究。研究结果是,波群中波动的最大振幅出现在波群前部而不是出现在波群中央,这种不对称性导致波群前部单个波出现大波陡的概率大于后部单个波出现大波陡的概率;进一步的波破碎统计发现波群前部单个波破碎的频率是后部单个波破碎频率的4倍。因此认为,波群结构的不对称性能够导致单个波发生破碎的位置出现在波群前部,这对风浪研究具有重要意义。

In this paper, the steepness distributions and breaking of individual waves in wave groups have been studied. The maximum amplitude of individual waves occurs in the front of a wave group rather than in the middle. Such asymmetry of a wave group structure makes it more probable that larger steepness occurs on the individual waves in the front of the wave group than those in the rear. In other words, the average steepness of the individual waves at the beginning of a wave group is larger, resulting in higher probability that the individual waves in the front of the wave group break according to the statistics of wave breaking （the breaking probability of the individual waves in the front of a wave group is about four times of that in the rear of the wave group）. Since wave breaking plays very important role in wind wave growth, these results are important for further study of wind wave.