杂交有限元计算港湾谐振  

HYBRID ELEMENT MODELING OF HARBOR RESONANCE

作　　者：朱蔚文[1] 

机构地区：[1]中山大学

出　　处：《海洋工程》1990年第1期76-84,共9页The Ocean Engineering

摘　　要：本文给出一个计算在岸边或离岸港湾谐振的杂交有限元方法;考虑海底部的粘性影响和岸边存在吸收作用的情况。粘性假设正比于流体速度,相位存在差异。沿固体岸壁的吸收边界条件公式类似于声学中的阻抗条件。所谓杂交有限元方法为:在近区域建立一个基于变分原理的泛函,用有限元法进行数值计算,远区域解满足常深度的Helmholtz方程。近场解和远场解在两区域的交界面上耦合。 为检验计算结果的准确性,考虑具有能量耗损时,以窄长矩形港湾为例,并将数值计算结果与分析解结果和Ippen的试验结果进行比较。具有岸边吸收作用的数值结果和具有边界吸收的圆柱绕射问题的分析解进行比较。结果表明,这种数值计算模型用于计算任意形状的港湾的谐振问题是十分有效的。This paper presents a hybrid element method for calculating harbor resonance in a coastal or offshore harbor under the effects of friction and boundary absorption. The friction term is assumed to be proportional to the flow velocity with a phase difference. The boundary absorption adopts a condition similar to the impedance condition in acoustics. In the near region a variational principle is established. In the far region the solution satisfies the Helmholtz equation.A numerical result of a fully open rectangular harbour with dissipation term is compared with the Ippen's [11] laboratory data. Another numerical result with the boundary absorption is compared with the theoretical solution of scattering problem for a vertical cylinder. Computation results of harbor resonance by the present model show good agreement with laboratory data and theoretical result.

关 键 词：杂交有限元 HELMHOLTZ 变分原理 吸收边界条件 分析解 数值方法 流体速度 散射问题 数值计算 试验结果 

分 类 号：P75[天文地球—海洋科学]