An experimental study of two submerged breakwaters affecting wave propagation on a sloping bed

It is of great significance to understand how water waves propagate over two impermeable trapezoid submerged breakwaters in order to reduce coastal erosion damages induced by wind, wave, current or tide. Wave elevation were measured systematically by using capacitance-type wave probes in the wave flume with 1:20 smooth slope. Taking into account the linear and cnoidal waves, the influencing factors are studied experimentally, including the water depth h, the incident wave height H, the incident wave period T and the spacing between submerged breakwaters S, cnoidal waves can present the significant changes of η (The ratio of the wave height under the condition of ´have submerged breakwaters´ and ´no submerged breakwaters´) better. The changes of wave energy between ´have submerged breakwaters´ and ´no submerged breakwaters´ on a sloping bed are investigated by the Fast Fourier Transform (FFT), which shows that wave energy dissipation can be reached effectively.