Abstract Landslide tsunamis and impulse waves are hazardous events with severe socioeconomic impacts. A long standing problem with simulations of these events is the generation stage, where landslides and water interact. Depth-averaged models like the Saint-Venant or Boussinesq Equations lose their validity for such applications. Therefore, we have to rely on a full treatment of the hydrodynamics, for instance by applying the Navier-Stokes Equations and Computational Fluid Dynamics (CFD). However, applications of fully three-dimensional methods to landslide tsunamis are sparse, and have often been outperformed by depth averaged models when compared to experimental data. In this work, we evaluate the multiphase Navier-Stokes Equations as implemented in OpenFOAM® in terms of impulse wave generation. We focus on a simplified two-dimensional setup where the landslide consists of water, in order to circumvent additional complexities due to treatment of landslide rheologies. We conduct a thorough grid refinement study and compare results to experiments to investigate model convergence, stability, and accuracy. The simulations display good agreement with the experimental data if the Courant-Friedrichs-Lewy (CFL) condition, is modified to account for the specific properties of the multiphase system. Further, we use the validated model for sensitivity studies and to review various scaling relations for landslide g 150 m enerated tsunamis. The application of numerical models allows us to perform broad parametric tests and dissect the underlying physics of these predictive equations systematically. We found that the first wave crest may be well estimated by solely the landslide mass in our setting. Including additional properties related to landslide momentum can improve the predictive skill, while other parameters lead to no substantial improvement.

中文翻译：

---

使用 OpenFOAM 对理想化滑坡产生冲击波的数值模拟

摘要 滑坡海啸和脉冲波是具有严重社会经济影响的危险事件。模拟这些事件的一个长期存在的问题是滑坡和水相互作用的生成阶段。像 Saint-Venant 或 Boussinesq 方程这样的深度平均模型在此类应用中失去了有效性。因此，我们必须依靠对流体动力学的全面处理，例如通过应用 Navier-Stokes 方程和计算流体动力学 (CFD)。然而，全三维方法在滑坡海啸中的应用很少，与实验数据相比，深度平均模型的表现往往优于深度平均模型。在这项工作中，我们在脉冲波生成方面评估了在 OpenFOAM® 中实施的多相纳维-斯托克斯方程。我们专注于简化的二维设置，其中滑坡由水组成，以规避由于滑坡流变处理引起的额外复杂性。我们进行了彻底的网格细化研究，并将结果与​​实验进行比较，以研究模型的收敛性、稳定性和准确性。如果 Courant-Friedrichs-Lewy (CFL) 条件被修改以考虑多相系统的特定属性，则模拟显示与实验数据的良好一致性。此外，我们使用经过验证的模型进行敏感性研究，并审查滑坡 g 150 m 引发的海啸的各种比例关系。数值模型的应用使我们能够进行广泛的参数测试并系统地剖析这些预测方程的基础物理。我们发现，在我们的环境中，仅通过滑坡质量就可以很好地估计第一个波峰。包括与滑坡动量相关的附加属性可以提高预测技能，而其他参数不会导致实质性改进。