Wave Impact Simulations by an Improved Incompressible SPH Model

• Published in: Journal of waterway, port, coastal, and ocean engineering
• Main Authors: Gui, Qinqin, Shao, Songdong, Dong, Ping
• Format: Journal Article
• Language: English
• Published: 02.10.2013
• Subjects: Coefficients; Computational fluid dynamics; Computer simulation; Density; Divergence; Invariants; Marine; Mathematical models; Weighting
• ISSN: 0733-950X
• DOI: 10.1061/(ASCE)WW.1943-5460.0000239

This paper presented an improved incompressible Smoothed Particle Hydrodynamics (ISPH) method for wave impact applications. In most conventional ISPH techniques the source term of pressure Poisson equation (PPE) is usually treated by either a density invariant or a velocity divergence free formulation. In this work, we combined both the density invariant and velocity divergence free formulations in a weighted average form to determine the source term. The model is then applied to two problems: 1) dam breaking wave impact on a vertical wall and 2) the solitary wave run up and impact on a coastal structure. The computational results have indicated that the combined source term treatment can predict the wave impact pressure and force more accurately compared with using either one of them alone. It was further found that depending on the application cases, the influence of density invariant part and divergence free part could be quite different. For the more violent wave impact case, the divergence free part played a more prominent role in ensuring accurate force simulations, while in less violent wave impact cases, the density invariant part seems to be more significant. A systematic parametric study has shown that the weighting coefficient in the PPE source term is independent of particle spacing under different wave impact situations. Also a close relationship has been found between the ratio of flow height to length scales H/L and the weighting coefficient alpha in the mixed pressure source term.