An incompressible smoothed particle hydrodynamics (ISPH) wave basin with structure interaction for fully nonlinear and extreme coastal waves

在海岸和近海工程中，复杂的、通常高度非线性和扭曲的波浪运动，可能涉及破碎、钻孔传播、掺气、结构相互作用和剧烈冲击，在很大程度上仍然难以数值模拟。光滑粒子流体动力学（SPH）有很大的希望，因为它解决了拉格朗日形式的控制方程，其中每个粒子代表局部流体量的插值，这些流体量携带流量，如质量，压力，速度，并根据其基础力学移动。因此，SPH是一种无网格的方法，并拥有一些独特的优势，传统的基于网格的方法;没有明确的自由表面的处理，没有计算网格意味着复杂的网格是不需要复杂的流体或固体几何形状。该方法在基础开发和应用范围方面都进展迅速。一个SPH的方法已经开发出来，这是真正不可压缩的，准确的，几乎无噪声，但直到最近，数值不稳定性一直是一个困难。曼彻斯特最近的一项发展解决了这个问题，它保持了准确性、效率和相对简单性。无噪声方面对于流体/结构相互作用是重要的，因为噪声压力会污染力。滞留空气对冲击压力的影响也是重要的，表面张力决定了波浪破碎的性质。这两种效应可以合并到SPH中。该项目的目的是使ISPH方法成为一种有吸引力的工程工具，其代码能够处理非常大量的粒子，特别是在3D中，使用并行计算以实现广泛的应用。这将在三个层次上进行：单相不可压缩，几乎无粘流解算器;两相水/空气解算器，空气可压缩;两相水/空气解算器与表面张力为此，将开发一个3-D数值海岸波盆，包括任意几何形状的结构，如海堤，沉箱，风力涡轮机柱，港口，船舶。

In coastal and offshore engineering, complex, generally highly nonlinear and distorted, wavemotion, which may involve breaking, bore propagation, aeration, structure interaction and violent impact, has remained largely intractable to numerical modelling. Smoothed particle hydrodynamics (SPH) holds great promise since it solves the governing equations in Lagrangian form where each particle represents an interpolation of local fluid quantities that carry flow quantities such as mass, pressure, velocity and move according to their underlying mechanics. SPH is thus a meshless method and possesses some unique advantages over conventional mesh-based approaches; no explicit treatment of the free surface and no computational grid mean that sophisticated meshing is not needed for complex fluid or solid geometries. The method is advancing rapidly, both in fundamental development and in its range of applications. An SPH approach has been developed which is truly incompressible, accurate and virtually noise free but, until recently, numerical instability has been a difficulty. This has been solved by a recent development at Manchester which maintains accuracy, efficiency and relative simplicity. The noise-free aspect is important for fluid/structure interaction since noisy pressures would contaminate forces. The effects of trapped air on impact pressures is also known to be important and surface tension determines the nature of wave breaking. These two effects may be incorporated in SPH. The aim of this project is to make the ISPH method into an attractive engineering tool, with the code able to handle very large numbers of particles, particularly in 3-D, using parallel computing to enable a wide range of applications. This would be undertaken at three levels as: a single-phase incompressible, almost inviscid flow solver; a two-phase water/air solver, with air compressible; a two-phase water/air solver with surface tensionTo this end a 3-D numerical coastal wave basin will be developed with the option of including structures of arbitrary geometry such as sea walls, caissons, wind turbine columns, harbours, ships.