Numerical study on the wave attenuation performance of a water ballast type floating breakwater

Abstract

The influence of liquid sloshing within a water ballast type floating breakwater is numerically investigated to assess its effect on overall wave attenuation performance. Liquid sloshing increases the dissipation of incoming wave energy, thereby enhancing the wave attenuation performance. When the incident wave period approaches the natural frequency of the sloshing, resonance occurs in ballast tank, leading to significant non-linear sloshing inside the tank. Under the combined action of the internal liquid and external waves, the transmitted wave behind the floating breakwater is amplified, leading to a trend of reduced wave attenuation performance. The natural frequency of liquid sloshing can be adjusted by dividing the tank into two separate compartments with a baffle, the wave attenuation performance can be increased by up to 51.6%. In practical applications, the natural sloshing frequency in the ballast tank should be kept away from the design wave frequencies. This study presents novel perspectives and practical solutions within the realm of coastal protection engineering, offering valuable references for real-world engineering projects.