A Numerical Study on Wave Propagating Through In-Line Net Cages

A three-dimensional numerical model is established to simulate the interaction between waves and net cages. The porous-media fluid model is introduced to model the net cage in waves. An oscillating-boundary method is used to generate waves at one end of a tank partially filled with water. The flow motion of an incompressible, viscous fluid is described by Navier-Stokes equations and the free surface is tracked by volume of fluid (VOF) method. Validation of the numerical model is conducted by comparing the numerical results with the corresponding physical-model measurements of a net-cage model. In order to visualize the wave field around in-line net cages, numerical results of both wave elevation and water-particle-velocity distribution on a vertical plane of a transient field are presented. Compared with the undisturbed wave field, the effects of the net cages on both the wave elevation and the water-particle-velocity distribution around the net cages are noticeable. The study will contribute to understanding of the damping effect of a large fish farm on wave propagation.