Modelling and field testing of a breakwater integrated U OWC wave energy converter with dielectric elastomer generator
Abstract This paper introduces a theoretical and experimental study of a wave energy converter (WEC) that combines the two innovative concepts of U oscillating water column (U OWC) and dielectric elastomer generator (DEG) power take off (PTO) The U OWC is a type of oscillating water column that features a U shaped duct that is introduced to tune its dynamics to a certain wave period without active means of phase control. The DEG is a compliant polymeric generator that makes it possible to convert mechanical energy into electrical energy by exploiting the large deformations of elastomeric membranes. A lumped parameter mathematical model of the proposed WEC has been set up and a small scale model/prototype has been preliminary tested in a benign real sea environment. During experiments, relevant experimental data have been collected and used for assessing the reliability of the modelling approach. Beside the model validation, specific experiments have been conducted to test a simple but yet effective load shedding system based on the progressive opening of an air valve. Finally, a preliminary design of a full scale U OWC equipped with DEG PTO has been studied through wave to wire analysis. The obtained numerical results show an overall performance that is comparable with that of more conventional, expensive and complex PTO technologies.