Wave energy evolution during Bragg resonance reflection of waves interaction with submerged semicircular breakwaters through the smoothed particle hydrodynamics

A Smoothed Particle Hydrodynamics model is used to examine the wave interaction with the single and double-submerged semicircular breakwaters. The Large Eddy Simulation turbulence model is adopted to consider turbulence effects, and the particle packing technology is introduced into the numerical model to improve the computing accuracy. The numerical results of the free surface elevation in the wave interaction with the submerged breakwaters, the reflection coefficient, and the transmission coefficient of the submerged breakwaters are in good agreement with the experimental data. This indicates that the numerical model can effectively simulate the interaction process between the waves and the semicircular submerged breakwaters. Based on the numerical results, the Bragg reflection and wave energy dissipation generated by the double-submerged semicircular breakwaters (DSCB) are investigated, and the first and second resonances of Bragg reflections are determined. Additionally, the flow fields in various regions near the single-submerged semicircular breakwaters (SCB) are compared with those of the DSCB. It is found that the DSCB can dissipate more wave energy than the SCB, and the wave energy dissipation induced by the DSCB is mainly located at the first bar when Bragg resonance reflections occur.