A Modified Mild-Slope Model for the Hydrodynamic Analysis of Arrays of Heaving WECs in Variable Bathymetry Regions

Abstract

A simplified model based on the Modified Mild-Slope Equation with inclusions is developed for modelling the scattering of waves from multiple heaving point absorbers arranged in an array in general bottom topography. The model is used, in conjunction with a 3D BEM, in order to estimate the parameters modelling the energy extraction of the devices using data obtained from the hydrodynamic responses and performance of the single floating WEC. Subsequently, the present model is used for specific examples to calculate the wave field and the hydrodynamic performance of arrays of heaving WECs in constant depth and variable bathymetry regions and illustrate the effect of bottom slope and variation on the calculated wave field in the domain and in the vicinity of the devices. The present simplified model provides a low-cost first estimation of the wave conditions in the domain, which could be exploited as a supporting tool for best arrangement and park design purposes.

A 3D BEM-Coupled Mode Model for the Performance Analysis of Wave Energy Converter Parks in Nearshore-Coastal Regions

“…Moreover, reduced models can be applied to obtain results in an extended frequency range with low computational cost, such as the simplified 2D Modified Mild Slope Equation (MMSE) model, proposed in Ref. [7]. Gap resonance phenomena may also occur in hydrodynamic interaction problems, involving multiple floating bodies placed in close proximity [8,9].…”

“…Additionally, in Ref. [7], the operation of WECs is studied over irregular bathymetry by a 2D model, that makes use of the MMSE. In the latter work, the point absorbers are modeled on the free surface plane as energy absorbing circular inclusions, while the absorption parameters are calibrated by local 3D BEM formulations in constant local depth.…”