规则波作用下簇状沉水植物群消浪特性实验

Experimental Investigation on Wave Attenuation Under the Effects of Submerged Patchy Vegetation by Regular Waves

在理论分析的基础上通过物理模型实验探究了规则波与簇状沉水植物群的相互作用。结果表明,植物群沿程波高衰减规律在多数情况下与Kobayashi指数形式和Dalrymple幂函数形式波高衰减理论模型吻合较好,少数情况下波高衰减集中在植物群后半部分,与上述理论模型并不一致。在植物淹没度等于0.4条件下,植物群沿程波高出现较多壅高现象,且相对壅高值随入射波高的增大而减小;植物群的规则波透射系数变化情况与入射波周期、相对波高、植物淹没度以及植物分布密度等因素相关。当入射波周期等于1.0 s时,透射系数随相对波高的增大而减小,周期大于1.0 s时,透射系数随相对波高的增大出现较强的波动性。本文提出了规则波透射系数与水动力因素及植物因素之间的关系式,得到了近岸簇状沉水植物群消浪特性的基本认识,为采用近岸植物消波护岸提供一定的理论依据。

This study experimentally investigated the interaction of regular waves with submerged patchy vegetation,based on theoretical analysis.The results show tha in most cases,wave decay along the vegetation belt fits well to the laws of power or exponential proposed by Dalrymple and Kobayashi respectively.While in few cases,the reduction of wave height foucused on the second half of the vegetation belt.Moreover,the rising of wave height was observed when submergence ratio equal 0.4 and the relative rising values of wave height decrease with increasing wave height;The variation of transmission coefficients is related to incident wave periods,relative wave height,submergence ratio and distribution densities.The transmitted coefficients decreases with increasing relative wave height when T equal 1.0 s and it shows siginificant fluctation when T is larger than 1.0 s.Changes of transmission coefficients are functions of the hydrodynamics and vegetation factors.A basic understanding of wave dissipation characteristics of submerged patchy vegetation is put forward.The purpose of this paper is to provide theoretical basis on coastal protection.