Numerical and experimental study on local scour in front of OWC-BWS under waves

In this paper, a system of an oscillating water column wave energy converter integrated with a vertical breakwater (OWC- BWS) was established, and the scour mechanism in front of OWC-BWS under wave actions was studied by laboratory scale experiments and gas-liquid-particle flow numerical simulation, respectively. The experiment investigates the comparison of scour test results between a conventional vertical breakwater and OWC-BWS. It shows that compared to a vertical breakwater without an OWC, the local scour phenomenon in front of the OWC-BWS was effectively mitigated (test results showed a 46.7% reduction in the maximum scour depth). For numerical simulation, a scour model under wave actions was established for further research on the local scour mechanism in front of the OWC-BWS. It was found that the local scour topography of an OWC-BWS is different from that of a vertical breakwater. The OWC device effectively weakens the scour in front of the OWC-BWS, which is because the flow field in front of the OWC-BWS shows frequent generation and shedding of vortexes. In addition, as a crucial part of the OWC-BWS, the effect of PTO was also studied, which found that the maximum equilibrium scour depth was significantly influenced under different PTO.