Numerical Investigation of Solitary Wave Interaction with Double Row of Vertical Slotted Piles

Abstract

Destructive tsunami waves may cause failure of the pile-supported nearshore structures, hence, accurate prediction of tsunami wave interaction with piles is a primary engineering concern in the field of coastal management and hazard mitigation. This study numerically investigated tsunami-like solitary waves propagating over a surface-piercing double row of vertical slotted piles. A three-dimensional numerical wave tank based on an open-source computational fluid dynamics (CFD) tool was developed in this study. The Navier-Stokes equations for two-phase incompressible flow were solved using the large eddy simulation (LES) method for turbulence closure and the volume of fluid (VOF) method for tracking the free surface. Laboratory measurements of the wave, flow, and dynamic pressure were performed to validate the numerical model. The model was then applied to examine the three-dimensional distribution of free-surface elevation and the vertical distribution of dynamic pressure in the vicinity of the piles. Via numerical results, the variations of wave runup and impact force on the piles were also analyzed in view of the wave nonlinearity and the ratio of pile spacing to its diameter. Finally, the drag coefficients were discussed through the Morison equation to account for the interfering effects among the piles.