Numerical analysis of the fluid-dynamic behavior of a submerged plate wave energy converter

Abstract

The need for clean and renewable energy sources has nowadays contributed to give relevance to the study of sea wave energy. In this context, the present work brings a computational modeling to analyze the fluid-dynamic behavior of a submerged plate wave energy converter. Basically, its operating principle consists in the passage of sea waves through a horizontal submerged plate, generating a flow under it where a turbine is placed, converting mechanical energy into electrical energy. The numerical model uses the software GAMBIT and FLUENT. In the latter, which is based on the finite volume method (FVM), the methodology used to represent the air−water interaction in the numerical simulations of the device is the multiphase volume of fluid (VOF) method. The objective of this paper is to analyze the influence of the opening ratio under the submerged plate with regard to its efficiency. To do so, the model, after verification and validation processes, was used in six simulations that differ from each other only in the vertical position of the plate in a wave tank. Results showed that a 5% increase in the opening ratio may produce an approximately 93% increase in the efficiency of the converter. In addition, a physical restriction was inserted under the plate, representing the pressure drop caused by a turbine, and other cases were simulated. These results indicate that a reduction of around 76% in the free region under the plate causes a decrease of only 5.5% in the submerged plate efficiency.