Geometric evaluation of the main operational principle of an overtopping wave energy converter by means of Constructal Design. (April 2018)

• Record Type: Journal Article
• Authors: Martins, J.C.; Goulart, M.M.; Gomes, M. das N.; Souza, J.A.; Rocha, L.A.O.; Isoldi, L.A.; dos Santos, E.D.
• Is Part Of: Renewable energy. Volume 118(2018)
• Page Start: 727
• Page End: 741
• Publication Date: 2018-04
• Subjects: Wave energy -- Constructal Design -- Overtopping device -- Geometric evaluation -- Numerical study; Renewable energy sources -- Periodicals; Power resources -- Periodicals; Énergies renouvelables -- Périodiques; Ressources énergétiques -- Périodiques; 333.794
• DOI: 10.1016/j.renene.2017.11.061
• Languages: English
• ISSNs: 0960-1481

Abstract

Abstract: Current work aims to study the geometry of an overtopping wave energy converter in real scale using Constructal Design. Problem studied here is submitted to two constraints (areas of wave tank and overtopping ramp) and two degrees of freedom: ratio between the height and length of ramp ( H 1 / L 1 ) (or ramp slope, β ) and distance between the bottom of wave tank and the device ( S ). The effect of H 1 / L 1 and S over dimensionless device available power ( P d ) is evaluated for three different ramp area fractions ( ϕ ) and two different monochromatic waves. Conservation equations of mass, momentum and one equation for the transport of water volume fraction are solved with the finite volume method. To tackle with water-air mixture, multiphase model Volume of Fluid is used. Results showed the applicability of Constructal Design for improvement of device performance. For fixed magnitudes of S, the highest magnitudes of P d are achieved for the lowest possible ratio of H 1 / L 1 . For smaller construction areas of the ramp, intermediate magnitudes of S led to the highest magnitudes of P d, i.e., the sinking of device does not led necessarily to the best performance. Moreover, optimal shapes are not universal (the same) for the two wave conditions studied. Highlights: Constructal Design was applied to evaluate numerically the geometry of an overtopping wave energy converter. Numerical simulations of water-air mixture in two-dimensional domain for several configurations of the overtopping ramp. Results showed applicability of Constructal Design for improvement of overtopping device performance. Best performances studied here are dependent of combination of ramp geometry and its submergence. The best geometrical configuration of overtopping device changed for different incident waves.