Computational wave dynamics for innovative design of coastal structures

Abstract

For innovative designs of coastal structures, Numerical Wave Flumes (NWFs), which are solvers of Navier-Stokes equation for free-surface flows, are key tools. In this article, various methods and techniques for NWFs are overviewed. In the former half, key techniques of NWFs, namely the interface capturing (MAC, VOF, C-CUP) and significance of NWFs in comparison with the conventional wave models are described. In the latter part of this article, recent improvements of the particle method are shown as one of cores of NWFs. Methods for attenuating unphysical pressure fluctuation and improving accuracy, such as CMPS method for momentum conservation, Higher-order Source of Poisson Pressure Equation (PPE), Higher-order Laplacian, Error-Compensating Source in PPE, and Gradient Correction for ensuring Taylor-series consistency, are reviewed briefly. Finally, the latest new frontier of the accurate particle method, including Dynamic Stabilization for providing minimum-required artificial repulsive force to improve stability of computation, and Space Potential Particle for describing the exact free-surface boundary condition, is described.

On the state-of-the-art of particle methods for coastal and ocean engineering

“…With respect to crucial properties of coastal/ocean hydrodynamics characterized by violent/complex free surface flows, e.g. in wave breaking, overtopping, run-up, wave impact, green water, etc., Lagrangian meshfree particle methods have been proven to be excellent computational candidates [Violeau and Rogers, 2016;Gotoh and Okayasu, 2017].…”

“…Colagrossi et al, 2015;Wei et al, 2015]. Several important key features of particle methods for coastal/ocean engineering applications have been highlighted in a number of review papers [Koshizuka, 2011;Shadloo et al, 2016;Gotoh and Khayyer, 2016;Violeau and Rogers, 2016;Gotoh and Okayasu, 2017].…”

“…Lee et al, 2008]. In general, projection-based particle methods are expected to possess higher levels of accuracy, especially in terms of pressure calculation and volume conservation, provided that accurate/consistent differential operator models are applied along with careful implementations of boundary conditions [Gotoh and Okayasu, 2017]. This paper aims at reviewing several latest advancements made in the field of particle methods, with applications in coastal/ocean engineering.…”

SPH‐based numerical treatment of the interfacial interaction of flow with porous media

“…However, if one compares these pressure distributions qualitatively with the ones obtained by Khayyer et al, it is clear that the present results are not as smooth as the latter. This could be due to the superiorities of the projection‐based ISPH method and the higher‐order pressure solution scheme adopted in their work …”

“…This could be due to the superiorities of the projection-based ISPH method and the higher-order pressure solution scheme adopted in their work. 25 To validate the accuracy of the model in the reproduction of velocity field close to the porous structure, the velocity profiles at x = 0.04 m, 0.08 m, and 0.12 m (above the structure) at t = 1.45 s, 1.65 s, and 1.85 s (when the wave is travelling above the structure) are presented and compared with the experimental data of Wu and Hsiao 24 (for comparisons at other times and sections refer to 13 ). Figures 11 and 12 present the horizontal and vertical velocity profiles in comparison with the experimental profiles, and Table 2 presents the MAE values of those profiles with respect to the experimental data.…”