Wave power focusing due to the Bragg resonance

Flume Experiments on Energy Conversion Behavior for Oscillating Buoy Devices Interacting with Different Wave Types

“…(1) For the cases of partial standing waves, the corresponding wave field are induced by Bragg resonance. In the study of the effects of Bragg resonance on the performance o wave energy generation [35], five fixed continuous sinusoidal wavy bottoms (Figure 6 were installed in the flume to induce the Bragg resonance, whose wavelength is 0.9 m and height is 0.3 m. Figure 7 presents the experimental devices' layout for partial standin waves induced by Bragg resonance. (1) For the cases of partial standing waves, the corresponding wave field are induced by Bragg resonance.…”

“…(1) For the cases of partial standing waves, the corresponding wave field are induced by Bragg resonance. In the study of the effects of Bragg resonance on the performance of wave energy generation [35], five fixed continuous sinusoidal wavy bottoms (Figure 6) were installed in the flume to induce the Bragg resonance, whose wavelength is 0.9 m and height is 0.3 m. Figure 7 presents the experimental devices' layout for partial standing waves induced by Bragg resonance. According to the dispersion relation and the bottom designed, the incident wave period corresponding to the resonance peak T p is 1.15 s, which means that the Bragg resonance effect is strongest at 1.15 s. Thus, the value of incident wave period T is centered on 1.15 s and varies within an appropriate range, in which case strong Bragg resonance can be generated.…”

“…(2) For the cases of travelling waves, the wave height of travelling waves at the location of buoy was calibrated to be the same as partial standing waves [35]. In the cases of travelling waves, all five rippled bottoms have been removed from the flume.…”

“…Furthermore, the reflection coefficient is calculated by the incident-reflected separation method of Mansard [39]. The detailed information of the reflection coefficient by Bragg resonance has been introduced in Tao [35].…”

“…Tao [35] preliminarily studied the behavior of wave energy generation enhancement by Bragg resonance through physical model experiments, that is, through the interaction between incident waves and periodic wavy bottom. Thus, the wave energy density of the target region is increased.…”