当前位置: X-MOL 学术Comput. Fluids › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
A generating and absorbing boundary condition for dispersive waves in detailed simulations of free-surface flow interaction with marine structures
Computers & Fluids ( IF 2.8 ) Pub Date : 2020-03-01 , DOI: 10.1016/j.compfluid.2019.104387
Peter Wellens , Mart Borsboom

Abstract The boundaries of numerical domains for free-surface wave simulations with marine structures generate spurious wave reflection if no special measures are taken to prevent it. The common way to prevent reflection is to use dissipation zones at the cost of increased computational effort. On many occasions, the size of the dissipation area is considerably larger than the area of interest where wave interaction with the structure takes place. Our objective is to derive a local absorbing boundary condition that has equal performance to a dissipation zone with lower computational cost. The boundary condition is designed for irregular free-surface wave simulations in numerical methods that resolve the vertical dimension with multiple cells. It is for a range of phase velocities, meaning that the reflection coefficient per wave component is lower than a chosen value, say 2%, over a range of values for the dimensionless wave number kh. This is accomplished by extending the Sommerfeld boundary condition with an approximation of the linear dispersion relation in terms of kh, in combination with vertical derivatives of the solution variables. For this article, the boundary condition is extended with a non-zero right-hand side in order to prevent wave reflection, while, at the same time, at the same boundary, generating waves that propagate into the domain. Results of irregular wave simulations are shown to correspond to the analytical reflection coefficient for a range of wave numbers, and to have similar performance to a dissipation zone at a lower cost.

中文翻译:

自由表面流动与海洋结构相互作用的详细模拟中色散波的生成和吸收边界条件

摘要 如果不采取特殊措施来防止,海洋结构自由表面波模拟的数值域边界会产生杂散波反射。防止反射的常用方法是以增加计算工作量为代价使用耗散区。在许多情况下,耗散区域的大小远大于与结构发生波相互作用的感兴趣区域。我们的目标是推导出一个局部吸收边界条件,它具有与耗散区相同的性能,但计算成本较低。边界条件设计用于数值方法中的不规则自由表面波模拟,该方法可解析具有多个单元的垂直维度。它适用于一系列相速度,这意味着在无量纲波数 kh 的值范围内,每个波分量的反射系数低于选定值,例如 2%。这是通过扩展 Sommerfeld 边界条件来实现的,该边界条件以 kh 为单位的线性色散关系的近似值,并结合解变量的垂直导数。对于本文,边界条件扩展为非零右侧以防止波反射,同时在同一边界处生成传播到域中的波。不规则波模拟的结果显示出对应于一系列波数的解析反射系数,并且以较低的成本具有与耗散区相似的性能。在无量纲波数 kh 的值范围内。这是通过扩展 Sommerfeld 边界条件来实现的,该边界条件以 kh 为单位的线性色散关系的近似值,并结合解变量的垂直导数。对于本文,边界条件扩展为非零右侧以防止波反射,同时在同一边界处生成传播到域中的波。不规则波模拟的结果显示出对应于一系列波数的解析反射系数,并且以较低的成本具有与耗散区相似的性能。在无量纲波数 kh 的值范围内。这是通过扩展 Sommerfeld 边界条件来实现的,该边界条件以 kh 为单位的线性色散关系的近似值,并结合解变量的垂直导数。对于本文,边界条件扩展为非零右侧,以防止波反射,同时在同一边界处生成传播到域中的波。不规则波模拟的结果显示出对应于一系列波数的解析反射系数,并且以较低的成本具有与耗散区相似的性能。结合解变量的垂直导数。对于本文,边界条件扩展为非零右侧,以防止波反射,同时在同一边界处生成传播到域中的波。不规则波模拟的结果显示出对应于一系列波数的解析反射系数,并且以较低的成本具有与耗散区相似的性能。结合解变量的垂直导数。对于本文,边界条件扩展为非零右侧,以防止波反射,同时在同一边界处生成传播到域中的波。不规则波模拟的结果显示出对应于一系列波数的解析反射系数,并且以较低的成本具有与耗散区相似的性能。
更新日期:2020-03-01
down
wechat
bug