Wave power absorption with wave energy converters

Wave power absorption with Wave Energy Converters (WECs) arrays and isolated WEC is predicted with an in-house transient wave-multibody numerical tool of ITUWAVE which uses time marching scheme to solve a Boundary Integral Equation (BIE) for the analyses of hydrodynamic radiation and exciting forces. The hydrodynamics part of the solution is solved as impulsive velocity problem. Mean interaction factor, which can have constructive or destructive effect and determines the performances of WECs, is approximated with different configurations. A discrete control of latching is used to increase the bandwidth of the efficiency of WECs. When latching control applied to WEC in the case of off-resonance condition it increases the amplitude of the motion as well as absorbed power. The effects of the separation distances between array system and heading angles on energy absorption in both sway and heave modes are studied with numerical simulations which show sway mode has wider bandwidth than heave mode. The wave interactions are stronger when the array systems are closer proximity, and these wave interactions reduce significantly and shifted to larger times when the separation distances increase. The perfect reflection of incident waves from a vertical wall is considered with method of images. The vertical wall effect plays significant role over hydrodynamic parameters as the radiation and exciting forces show quite different behaviour in the case of WECs with and without vertical wall in an array system. The numerical results show that the performance and wave power absorption with WECs arrays in front of vertical wall are much greater compared to WECs arrays without vertical wall effect. The satisfactory agreements are obtained when the present ITU-WAVE numerical results for different hydrodynamic parameters are compared with analytical and other published numerical results.