Numerical Study Of Wave Interaction With Perforated Caisson

Perforated caisson, a new type of port and costal protection structure, which has large advantages in decreasing wave reflection and engineering coast, has been widely used in scientific research and engineering since it was been put forward in the middle of lase century. Recently, the physical model test results of wave interaction with perforated caisson is relatively abundant, but the numerical simulation research, especially the interaction between waves and double-layered perforated caisson, is lacking, meanwhile, the numerical method is relatively single. Therefore, it is necessary to spread out researches in this area.A two-dimensional numerical flume based on the Navier-Stokes equations which were discretized with a three-step finite element method was developed to simulate regular water wave problems. In this numerical model, large eddy simulation method was used to describe the turbulent effect and computational Lagrangian-Eulerian advection remap and the volume of the fluid method (CLEAR-VOF) was used to advect free surfaces. The reflection coefficient of single-layered perforated caisson and the ratio of the total horizontal force acting on the single-layered perforated caisson to them acting on the solid caisson have been studied under linear regular waves by using this numerical method. Through the comparison with physical model test and numerical calculation of other scholars, it can be known that the numerical method may be useful for studying wave interaction with perforated caisson.The reflection coefficient of double-layered perforated caisson and the ratio of the total horizontal force at wave crest calculated by numerical method are also in good agreement with the experimental ones. The experience formula of total horizontal force at wave through, mainly affected by the total relative chamber width and relative depth is fitted.Finally, an engineering project has been took for example to demonstrate that the numerical model built in this paper is feasible and applicative to research wave interacted with perforated caisson.