Wave load on submerged quarter-circular and semicircular breakwaters under irregular waves

• Published in: Coastal engineering (Amsterdam) 2017-03, Vol.121, p.265-277
• Main Authors: Jiang, Xue-Lian, Zou, Qing-Ping, Zhang, Na
• Format: Article
• Language: English
• Subjects: Irregular waves; Pressure; Submerged circular-front breakwaters; Vorticity; Wave load model
• ISSN: 0378-3839; 1872-7379
• DOI: 10.1016/j.coastaleng.2016.11.006

Laboratory experiments were conducted to investigate the characteristics of wave loading on submerged circular-front breakwaters due to irregular waves. The wave force spectrum for a semicircular breakwater is similar to that for a quarter-circular breakwater. The dimensionless peak wave force for irregular waves is less than that for regular waves. The performance of our theoretical wave load model is improved significantly by incorporating the effect of wave transmission and flow separation. A RANS-VOF model was used to investigate the effect of local hydrodynamic disturbances by submerged breakwaters on the pressure distribution around the breakwater and total wave load. The numerical results reveal that wave-induced vortices at the structure have a substantial influence on the wave loading on the submerged quarter-circular breakwater but not on the semicircular breakwater. A parametric analysis is required to further improve the relationship between wave loads and the vortices. •Submerged quarter-circular and semicircular breakwaters have similar force spectra.•Wave load under irregular waves is smaller than that under regular waves.•Improved wave load model by incorporating wave transmission and flow separation and vortex effect.•The effect of vorticity on the dynamic pressure is examined using RANS-VOF model.•Correlation between vortex and wave load was found.