潜堤对破碎区至冲泻区水动力特性影响数值分析  

Numerical analysis of surf and swash zone hydrodynamics under the influence of submerged breakwater

作　　者：陈杰[1,2] 蒋昌波[1,2] 刘虎英[1] 刘胜宇[1] 

机构地区：[1]长沙理工大学水利工程学院,湖南长沙410004 [2]湖南省水沙科学与水灾害防治重点实验室,湖南长沙410004

出　　处：《水科学进展》2011年第3期382-390,共9页Advances in Water Science

基　　金：国家自然科学基金资助项目(5097900850909009);水沙科学与水灾害防治湖南省重点实验室基金资助项目(2010SS09)~~

摘　　要：破碎区至冲泻区水动力特性分析是研究近岸地区泥沙输运机理和岸滩演变的关键。考虑潜堤修建的影响,对破碎区至冲泻区水动力特性开展研究。运用基于RANS方程的波浪数学模型,选取非线性涡粘性k-ε紊动传输模型,采用高精度PLIC-VOF方法追踪自由面,并用实验数据验证模型精度。计算分析结果表明,潜堤的修建改变了破波点的位置,破碎区至冲泻区内水动力特性随之变化,入射波波高H、波长L、堤顶水深R和堤顶宽度B是主要影响因素。在相同的入射波条件下,B/R增大,破碎区至冲泻区内出现的最大紊动动能值和最大紊动耗散值减小。用量纲一参数Re,Fr和St来描述破碎区至冲泻区水动力特性,随着RL/BH增大,波浪将在离岸较近处发生破碎,Re和Fr增大,St减小。The study of hydrodynamics in the surf and swash zone is essential to understanding the nearshore sediment transport and coast beach evolution.A numerical model is developed to analyze the flow mechanism in surf and swash zone under the influence of submerged breakwater.The two-dimensional Reynolds Averaged Navier-Stokes equations,together with a nonlinear k-ε turbulence model,and a finite difference method are employed in the model development.For a better simulation of wave breaking,a piecewise linear interface construction volume of fluid technique is utilized,which has good accuracy in describing air/water surfaces.The numerical model is validated with the experimental data and used to analyze the influence of submerged breakwater.The numerical results indicate that the location of breaking point and hydrodynamic characteristics in surf and swash zone are changed by the submerged breakwater.The wave height（H）,wave length（L）,depth of submergence（R） and crest width（B） play an important role in influencing hydrodynamic processes in these two zones.Under the same incident wave,the maximum turbulent kinetic energy and turbulence dissipation rates in two zones decrease as B/R increases.The dimensionless numbers of Re,Fr and St are deduced form RANS equations and used to describe hydrodynamics in surf and swash zones.The wave breaking could take place near the shore as RL/BH increases,meanwhile Re and Fr increases,and at the same time St decreases.

关 键 词：冲泻区 破碎区 潜堤 水动力特性 PLIC-VOF 

分 类 号：P731.22[天文地球—海洋科学] TV139.2[水利工程—水力学及河流动力学]