利用数值耗散层改进Boussinesq模型的无反射边界条件  

A NON-REFLECTING BOUNDARY CONDITION USING NUMERICAL DISSIPATION IN BOUSSINESQ MODELS

作　　者：王岗[1,2] 许建武[3] 郑金海[1,2] 

机构地区：[1]河海大学水文水资源与水利工程科学国家重点实验室,南京210098 [2]河海大学港口海岸与近海工程学院,南京210098 [3]中交第四航务工程勘察设计院有限公司,广州510230

出　　处：《工程力学》2012年第10期239-243,共5页Engineering Mechanics

基　　金：国家自然科学基金项目(50979033);水文水资源和水利工程科学国家重点实验室团队专项研究项目(2009585812)

摘　　要：Boussinesq方程是近年来比较理想的模拟近岸波浪的一个模型,它可以考虑波浪的色散、变浅和非线性等一系列因素,其数值模型的吸收边界通常使用一种能在较大的频率范围内减弱波浪的数值海绵层。该文从理论上提出一种利用数值耗散模拟波浪无反射边界条件的方法。通过模拟规则波和随机波在水槽的传播表明该方法可以达到与海绵层相同的效果。由于该方法不需要修改模型代码,仅需在开边界处增加一段网格逐渐增加的耗散带,操作简便,有很强的实用性。Boussinesq equations have been verified to be accurate and revealing predictors of a wide range of nearshore hydrodynamic behaviour,including wave dispersion,shoaling,nonlinear interaction and a range of additional topics.In order to reduce the boundary reflection,a sponge boundary layer is usually integrated in the model,which can absorb wave energy in a rather wide frequency range.The paper presents a non-reflecting boundary condition using numerical dissipation approach in Boussinesq equations discrete.The calculation results of regular waves and random waves show that this method can provide the same simulations with the method of sponge layer.Since the method just uses a layer with the grid space increased gradually to dissipate the wave energy at the open boundary,and does not require modifying the model code,it is practical.

关 键 词：无反射边界 Boussinesq模型 水波模拟 数值耗散 数值模拟 

分 类 号：TV139.2[水利工程—水力学及河流动力学]