风浪周期分布与谱宽度的关系

本文通过分析实验室风浪周期分布,发现风浪周期累积概率分布曲线低于Longuet-Higgins理论结果,在小概率周期区域实验结果与理论结果的差异明显。对实验结果进一步分析发现,在谱不是很窄时,在小概率处风浪周期累积概率随谱宽度的增大而降低,这与窄谱假定下的理论结果相反,Longuet-Higgins理论结果在小概率处不便于描述周期分布随谱宽度的变化。根据实验结果提出风浪周期的Weibull分布经验公式,Weibull分布中的参数依赖于谱宽度。

DEPENDENCE OF THE DISTRIBUTION OF WIND WAVE PERIODS ON SPECTRAL WIDTH

The distribution of wind wave periods for waves in the laboratory is studied.It is found that the exceeding probability of wind wave periods is lower than the results of Longuet-Higgins' theory.The difference between the experimental and theoretical results is remarkable in the small probability region.It is found that for spectra which are not very narrow,the exceeding probability decreases with increasing spectral width.This is contrary to the results of narrow spectral width theory.In the small probability region,Longuet-Higgins'theory is inconvenient in describing the dependence of the distribution of wind wave periods with the spectral width.Based on the observations in the experiment,the Weibull distribution of wind wave periods is proposed.The parameters in the Weibull distribution depend on spectral width.