Numerical study of multidirectional focusing wave run-up on a vertical surface-piercing cylinder

In this article, a numerical model based on improved Boussinesq equations and the Finite Element Method (FEM) with unstructured triangular elements is proposed and verified by experimental results for the focusing wave group interaction with a vertical surface-piercing cylinder. The multidirectional focusing waves with different directional spreading parameters and their interaction with a vertical surface-piercing cylinder are numerically simulated. The directional spreading parameter influences the wave form, that is, a wider directional spreading would induce a narrower wave form in space. The wave run-up on the cylinder increases with the increase of the wave directional spreading parameter, but when the parameter is greater than 30–40, the wave run-up changes only slightly and the influence of the directional spreading can be neglected. A larger diameter cylinder may have a larger wave run-up at the front face. But at the back side, it is other way round.