Modelling Sand Foundation Behaviour Underneath Caisson Breakwaters Subject to Breaking Wave Impact
Modelling Sand Foundation Behaviour Underneath Caisson Breakwaters Subject to Breaking Wave Impact
复制标题
模拟沉箱防波堤下方受碎波冲击的沙基行为
DOI：
10.1115/omae2013-10281
复制
发表时间：
2013
影响因子：
2.4
通讯作者：
H. Oumeraci
中科院分区：
文献类型：
--
作者：
H. E. Safti;H. Oumeraci
为了再现沉箱式防波堤在波浪作用下的大型试验，建立了一个单向CFD-CSD耦合模型系统。利用全动态、全耦合Biot方程的有限体积法建立了计算结构动力学(CSD)模型。完全耦合的孔力学分析采用分离的方法，在迭代水平上将骨架位移、孔隙流体压力和孔隙流体速度(相对于骨架)解耦。采用PISO算法求解孔隙流体压力-速度耦合问题。介绍了对多孔介质公式的两种简化：(1)忽略孔隙流体的对流加速度；(2)完全忽略孔隙流体的加速度(u-p近似)。采用摩擦接触模型模拟土-结构相互作用。采用基于Drucker-Prager破坏准则的多面塑性模型，模拟了沉箱式防波堤在波浪作用下砂土地基的特性。利用体积平均速度原理，开发了一种可同时求解多孔介质内外流动的不可压缩(等密度)多相计算流体力学(CFD)求解器。采用渗流模型来模拟多孔介质的流动阻力，包括粘性项、过渡项、惯性项和瞬变项。在流体连续性方程中引入了一个附加项，以说明流体混合物(水和空气)的可压缩性(体积弹性系数的倒数)。CFD-CSD模型系统使用OpenFOAM®框架开发。
A one-way CFD-CSD coupled model system is presented to reproduce large scale experiments of a caisson breakwater, subject to wave attack. The Computational Structural Dynamics (CSD) model is developed using the finite volume method for the fully dynamic, fully coupled Biot equations. The fully coupled poro-mechanical analysis is handled in a segregated approach in which the skeleton displacement, the pore fluid pressure and the pore fluid velocity (relative to the skeleton) are decoupled at the iteration level. The pore fluid pressure-velocity coupling is resolved using the PISO (Pressure Implicit with Splitting of Operators) algorithm. Two simplifications to the porous media formulations were introduced: (1) neglecting convective acceleration of pore fluid and (2) fully neglecting acceleration of the pore fluid (the u-p approximation). A frictional contact model is implemented to model soil-structure interaction. A multi-surface plasticity model with the Drucker-Prager failure criterion is introduced to model the behavior of sand foundations under cyclic load posed by wave action on the caisson breakwater. An incompressible (constant density) multiphase Computational Fluid Dynamics (CFD) solver is developed for solving flow inside and outside porous media simultaneously using the principle of volume averaged velocity. A seepage model is implemented to model flow resistance of porous media that includes viscous, transitional, inertial and transient terms. An additional term is introduced to the fluid continuity equation to account for fluid mixture (water and air) compressibility (inverse of bulk modulus). The CFD-CSD model system is developed using the OpenFOAM® framework.© 2013 ASME