Numerical analysis of an onshore oscillating water column wave energy converter for different wall slopes

• Autor(a) principal: Güths, Angélica Konradt
• Data de Publicação: 2020
• Outros Autores: Teixeira, Paulo Roberto de Freitas, Didier, Eric
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Revista Interdisciplinar de Pesquisa em Engenharia
• Texto Completo: https://periodicos.unb.br/index.php/ripe/article/view/35053
• topic: oscillating water column; wave energy; renewable energy; numerical simulation

An alternative to the energy matrix expansion, due to the increase of global electricity demand, is the renewable sea wave energy source, which has high energy potential. The Oscillating Water Column (OWC) converter is one of the most studied, although it is not yet used at commercial scale. Therefore, searching the optimal geometric configuration is fundamental to turn this device viable. This study proposes a numerical analysis of an onshore OWC device for different slopes of chamber walls (from 40o to 90o) and equipped with a Wells turbine. Simulations are performed by means of the FLUENT® software, based on Reynolds-averaged Navier-Stokes (RANS) equations for an incompressible 2D flow, the k-É› turbulence model and the Volume of Fluid (VOF) method. Analyses of the behavior of run up/down in the front wall, sloshing inside the chamber and the energy balance of the OWC are carried out for incident waves with periods from 6 to 12 s and height of 1.5 m. Chamber with wall slopes of 40o reaches the highest extracted energy EE at wave periods of 9 and 10.5s (70% of the incident wave energy) and higher run-up/down on the front wall and sloshing inside the chamber. However, chamber with wall slopes of 90o has more regularity of EE at the range of wave periods, which allows concluding that the choice of the optimal chamber wall slope depends mainly on the sea state characteristics.