Wave power extraction by a submerged piezoelectric plate

A submerged elastic plate can work as a plate–wave energy converter (WEC) to capture wave power provided that piezoelectric layers are bonded to both faces of the flexible substrate. In this paper, the performance of a piezoelectric plate is investigated. The plate–WEC is simulated by a submerged elastic disk, which can be either simply supported or clamped at the edge. A theoretical model based on the linear potential flow theory and the eigenfunction matching method is developed to solve the hydroelastics of the device with the electro-mechanical and the hydrodynamic problems coupled together. The model is first validated by comparing the results of wave power absorption by using two different methods, i.e., a straightforward method and an indirect method in terms of far–field coefficients. The validated theoretical model is then applied to examine the effect of radius and submergence on wave power extraction of the plate–WEC. It is found that a plate–WEC with a smaller radius generally provides a better performance in terms of the averaged wave power that can be absorbed per unit area of the plate. The peaks and the overall level of the frequency response of dimensionless wave power absorption both rise dramatically as the plate edge condition changes into clamped from simply supported.