越浪堤后透射波周期特性研究

Study on transmitted mean wave period after low-crested breakwater

为了研究不规则波越过光滑堤后的波周期变化,本文基于近岸波浪传播变形非静压模型分析了相对淹没深度、深水波陡、相对堤顶宽度和坡度对越浪堤波周期变化的影响。根据数值模拟的结果建立了光滑越浪堤波周期透射系数的预测公式。结果表明:堤后平均波周期受高频谐波的影响小于入射波周期;堤顶相对淹没深度以及深水波陡是波周期透射系数的主要影响因子,且与其线性相关;相对堤顶宽度的影响次之,且出水堤时对于波周期透射系数变化的影响大于淹没堤;斜坡坡度对波周期透射系数的影响最不明显。将预测公式得到的预测值与实测值相比,确定性系数高达0.95,表明其良好的预测效果。

In this paper,to study the change of mean wave period after the smooth low crested breakwater under irregular waves,the influence of the relative submergences,wave steepness,the relative crest width and slope on wave period variation of low crested breakwater was discussed based on the non hydrostatic model simulating waves till shore.Based on the numerical results,an empirical formula of transmission coefficient of mean wave period was proposed.According to the analysis of the numerical results,the transmitted mean wave period is less than the incident mean wave period because of the generation of high frequency harmonics.Moreover,the relative submergences and wave steepness are the main factors linearly influencing the transmission coefficient of mean wave period.The relative crest width also has considerable effect on the transmission coefficient of mean wave period especially when the structure is non immersed.However,the seaside slope of the structure shows little effect on the transmission coefficient of mean wave period.The coefficients of determination between measurements and values calculated using the empirical formula is095,representing good predicting performance for mean wave period over a smooth low crested breakwater.