Comparing approaches for numerical modelling of tsunami generation by deformable submarine slides
Comparing approaches for numerical modelling of tsunami generation by deformable submarine slides
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DOI：
10.1016/j.ocemod.2016.02.007
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发表时间：
2016-04
期刊：
影响因子：
3.2
通讯作者：
Rebecca Smith;Jon Hill;G. Collins;M. Piggott;S. Kramer;Samuel D. Parkinson;Cian R. Wilson
中科院分区：
文献类型：
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作者：
Rebecca Smith;Jon Hill;G. Collins;M. Piggott;S. Kramer;Samuel D. Parkinson;Cian R. Wilson
与地震引发的海啸相比，海底滑坡引发的海啸可以说是一种未被充分考虑的风险。潜艇滑浪的数值模拟可以用来识别决定波浪特性的重要因素。在这里，我们使用Fluidity，一个开源的有限元代码，来模拟可变形的海底滑梯产生的波浪。Fluidity使用灵活的非结构化网格与自适应性相结合，可根据模拟状态改变网格拓扑和分辨率，在需要时聚焦或降低分辨率。流动性还允许采取一些不同的数值方法来模拟海底滑动变形，自由表面表示，和波的产生在同一数值框架。在这项工作中，我们使用多材料的方法，考虑两种材料（幻灯片和水与自由表面）或三种材料（幻灯片，水和空气），以及沉积物模型（沉积物，水和自由表面）的方法。在所有情况下，载玻片都被视为粘性流体。我们的结果是一致的实验室实验，使用可变形的海底幻灯片，并表现出良好的协议时，与其他数值模型相比。模拟海底滑坡动力学和海啸波生成的三种不同方法产生相似的波形和滑坡变形几何形状。但是，根据应用程序的不同，每种方法都有其自身的优点。网格自适应被证明是能够降低计算成本，而不影响结果的准确性。
Tsunami generated by submarine slides are arguably an under-considered risk in comparison to earthquake-generated tsunami. Numerical simulations of submarine slide-generated waves can be used to identify the important factors in determining wave characteristics. Here we use Fluidity, an open source finite element code, to simulate waves generated by deformable submarine slides. Fluidity uses flexible unstructured meshes combined with adaptivity which alters the mesh topology and resolution based on the simulation state, focussing or reducing resolution, when and where it is required. Fluidity also allows a number of different numerical approaches to be taken to simulate submarine slide deformation, free-surface representation, and wave generation within the same numerical framework. In this work we use a multi-material approach, considering either two materials (slide and water with a free surface) or three materials (slide, water and air), as well as a sediment model (sediment, water and free surface) approach. In all cases the slide is treated as a viscous fluid. Our results are shown to be consistent with laboratory experiments using a deformable submarine slide, and demonstrate good agreement when compared with other numerical models. The three different approaches for simulating submarine slide dynamics and tsunami wave generation produce similar waveforms and slide deformation geometries. However, each has its own merits depending on the application. Mesh adaptivity is shown to be able to reduce the computational cost without compromising the accuracy of results.