Interação de ondas com parques eólicos offshore de tipo monopilar

Abstract

The large spacing between turbines and the small diameter in relation to the length of the waves has traditionally justified not considering the impact of offshore wind farms (OWFs) on waves. However, the increasing number of OWFs that exceed 100 turbines makes it necessary to reevaluate the impact on waves. The aim of this study is to investigate the impact of monopiles OWFs on monochromatic waves. Studies were carried out using a wave-structure interaction model based on the first order potential theory (WAMIT®), considering arrangements from 1 to 70 monopiles and different wave conditions. First-order quantities, height and bottom velocity, and mean time-averaged second-order quantities, radiation stress, mean level and mass transport, were analyzed. Additionally, the research included wave propagation studies with a phase resolving model (MPO-SisBaHiA), and the comparison between the results obtained with the two models at a OWFs’ downdrift control line. The results showed that, despite the large spacing between monopiles, the resulting wave inside and outside the OWF is the result of multiple interactions between all the scattered waves generated by the structures. For certain OWF configurations and incident waves, the wave disturbance was relevant, capable of modifying the waves’s dynamics, the local sediment transport, and the coastal processes. The most significant impact was observed for cases with shorter periods and greater total number of monopiles that simultaneously affect a wave crest.