Experimental investigation on the power capture of an oscillating wave surge converter in unidirectional waves. (May 2020)

• Record Type: Journal Article
• Authors: Brito, Moisés; Ferreira, Rui M.L.; Teixeira, Luis; Neves, Maria G.; Canelas, Ricardo B.
• Is Part Of: Renewable energy. Volume 151(2020)
• Page Start: 975
• Page End: 992
• Publication Date: 2020-05
• Subjects: Wave energy -- Oscillating wave surge converter: OWSC -- Capture width ratio: CWR -- Response amplitude operator: RAO -- Power take-off: PTO damping; Renewable energy sources -- Periodicals; Power resources -- Periodicals; Énergies renouvelables -- Périodiques; Ressources énergétiques -- Périodiques; 333.794
• DOI: 10.1016/j.renene.2019.11.094
• Languages: English
• ISSNs: 0960-1481

Abstract

Abstract: The aim of this paper is the experimental characterization of the capture width ratio (CWR) and response amplitude operator (RAO) of a 1:10 physical model of an oscillating wave surge converter (OWSC), under unidirectional regular and irregular waves. The effects of hydraulic power take-off (PTO) system are explicitly taken in consideration. A mathematical model is proposed to describe the PTO damping as a function of the angular velocity of the flap. The harmonic decomposition of free-surface elevation, angular velocity of the flap and pressure in the PTO system demonstrates that these signals are dominated by their linear component. However, the signals also present some important higher-order frequency components. To predict the CWR of the OWSC under irregular waves the nonlinear output frequency response functions are considered as the extension of the RAO to the nonlinear case. It is shown and discussed that the PTO system, wave frequency and height have a significant influence on the CWR and RAO. The RAO curve for irregular waves does not exhibit a well-defined peak, showing a limited variation in a broadband. A weak correlation between CWR and RAO was found, i.e., the maximum CWR does not occur for the maximum value of RAO. Highlights: The CWR and RAO of an OWSC with hydraulic PTO system are investigated. Experimental campaign is carried out under both regular and irregular waves. A mathematical model is proposed to describe the damping effect of the PTO system. New analysis for predicting the CWR based on RAO is presented.