Experimental studies and time-domain simulation of a hinged-type wave energy converter in regular waves

Abstract

This paper presents the design concept of a hinged-type wave energy converter, Sea Wave Energy Extraction Device (Sea-WEED), and associated numerical and experimental studies of its performance in regular waves. The device is considered as an improved attenuator. A SeaWEED unit consists of four modules that are connected by rigid truss structures. The fourmodule array includes a non-energy producing nose module in the front, followed by two energy producing modules, and another non-energy producing module at the rear. A potential-flow-based time-domain program with the Lagrange multiplier approach was developed to simulate the dynamics of multiple constrained bodies. Model tests of a 1:35 scale model with and without the power takeoff (PTO) units were carried out to validate the numerical method. Friction dampers were designed and manufactured to mimic the PTO units. The validated time-domain method was applied to predict the absorbed power by the device in regular waves.

Hybrid wave/current energy harvesting with a flexible piezoelectric plate

“…A flexible thin structure with distributed wave energy converters, analogous to a piezoelectric plate, is a canonical rendition of a wide range of the above multi-segmented flexible energy harvesting concepts (Erturk & Inman 2011). Piezoelectric thin structures are employed to harvest wave energy directly (Viet, Wu & Wang 2017;Mutsuda et al 2019), or they are used as a model to study the asymptotic response of multi-segmented conventional devices, such as M4 and Pelamis, wherein the energy is captured from differential deformation of adjacent segments (Stansby, Moreno & Stallard 2015;Peng et al 2020). These systems, in the limit of many interconnecting bodies, resemble the canonical piezoelectric plate with infinitesimal neighbouring electrical circuits in which a simple mathematical model can capture the role of mechanical-to-electrical conversion as well as the resistance capacitance and inductance components of the electrical circuit (Doaré & Michelin 2011;Michelin & Doaré 2013).…”

“…2019), or they are used as a model to study the asymptotic response of multi-segmented conventional devices, such as M4 and Pelamis, wherein the energy is captured from differential deformation of adjacent segments (Stansby, Moreno & Stallard 2015; Peng et al. 2020). These systems, in the limit of many interconnecting bodies, resemble the canonical piezoelectric plate with infinitesimal neighbouring electrical circuits in which a simple mathematical model can capture the role of mechanical-to-electrical conversion as well as the resistance capacitance and inductance components of the electrical circuit (Doaré & Michelin 2011; Michelin & Doaré 2013).…”