|The Performance Assessment of Wave and Tidal Array Systems (PerAWaT) project, launched in October 2009 with £8m of ETI investment. The project delivered validated, commercial software tools capable of significantly reducing the levels of uncertainty associated with predicting the energy yield of major wave and tidal stream energy arrays. It also produced information that will help reduce commercial risk of future large scale wave and tidal array developments.
This deliverable is the first within the Wave sub-project. It describes the representation of wave energy converters in a third generation spectral wave model and begins by providing some background about the current state-of-the art for wave energy converter array representation. This is followed by the development of a general methodology for representing wave energy converters in a spectral-domain model, where the term spectral-domain model here refers to a numerical representation of the wave energy field which has been decomposed into frequency components.
Emphasis is placed on the ability of a spectral domain model to capture the nonlinear characteristics of a wave energy converter. Initial cross validation is provided by comparison of the derived spectral-domain model with a time-domain model in two separate examples of nonlinear wave energy converter characteristics (wave forcedecoupling, and quadratic drag). Additional cross-validation of the method is demonstrated though comparison with physical wave tank experiments carried out at Queen’s University Belfast. The deliverable subsequently focuses on the specific type of spectral-domain model that will be implemented in WG1 WG2, the spectral wave model, in which the wave energy converters will be represented.