Hydrodynamic Analysis of Surge-Type Wave Energy Devices in Variable Bathymetry by Means of BEM

Abstract

A variety of devices and concepts have been proposed and thoroughly investigated for the exploitation of renewable wave energy. Many of the devices operate in nearshore and coastal regions, and thus, variable bathymetry could have significant effects on their performance. In particular, Oscillating Wave Surge Converters (OWSCs) exploit the horizontal motion of water waves interacting with the flap of the device. In this work, a Boundary Element Method (BEM) is developed, and applied to the investigation of variable bathymetry effects on the performance of a simplified 2D model of a surge-type wave energy converter excited by harmonic incident waves. Numerical results, illustrating the effects of depth variation in conjunction with other parameters, like inertia and power-take-off, on the performance of the device, are presented. Finally, a comparative evaluation of the present simplified surge-type WEC model and point absorbers is presented for a case study in a selected coastal site on the Greek nearshore area, characterized by relatively increased wave energy potential.

A BEM for the Hydrodynamic Analysis of Oscillating Water Column Systems in Variable Bathymetry

“…As a result, the effects caused to their response due to the presence of bathymetric inhomogeneities Energies 2020, 13, 3403 2 of 22 could be significant and need to be accounted for. This has been illustrated in the case of WEC point absorbers-e.g., [3,4]-as well as surge-type devices [5] operating in variable bathymetry regions, for which Boundary Element Method (BEM) models have been developed; it is shown that the bottom slope and curvature could alter the performance curves of the systems, especially in shallow water conditions.…”

Assessing Renewable Resources at the Saronikos Gulf for the Development of Multi-Generation Renewable Systems

“…The area has a low energy density resource potential, due to its sheltered characteristics and changes in bathymetry. However, even in such an area, the mean wave energy resource was 0.13-0.17 kW/m (130-170 W/m), which can be harnessed efficiently and contribute to local power production [34,35]. As waves propagate further into the Gulf, the islands of Aigina and Salamina are the main natural elements (obstacles) that reduce waves.…”

Study on the Resonant Behaviors of a Bottom-Hinged Oscillating Wave Surge Converter

“…Boundary element method (BEM) numerical simulation, based on potential flow theory, was employed in the analysis of OWSCs under waves, and validated via experiments [10]. Some hydrodynamic studies of OWSCs based on BEM 2 of 28 can be found in [11][12][13]. BEM has the merit of efficient computation, but the nonlinearities, e.g., wave breaking [14], flow separation [15], vortex shedding [16], slamming [17], and wave overtopping, cannot be perfectly considered.…”