Open AccessEnhancement of a 3-DOF submerged wave energy device using bistability
Author(s) -
Benjamin Schubert,
William S. P. Robertson,
B. Cazzolato
Publication year - 2020
Publication title -
international marine energy journal
Language(s) - English
Resource type - Journals
ISSN - 2631-5548
DOI - 10.36688/imej.3.73-82
Subject(s) - bistability , drag , power (physics) , dimensionless quantity , control theory (sociology) , mechanics , physics , optoelectronics , computer science , thermodynamics , control (management) , artificial intelligence
The dynamic response of a submerged CETO shaped quasi-point absorbing wave energy converter coupled to a bistable power take off is presented in this study. Whilst the impact of bistability has been shown in a limited number of situations to improve the amount of power generated, many models have been restricted to a single degree of freedom and often ignore drag effects. To overcome these model limitations, a submerged single tether point absorber with a bistable power take off was modelled using both 1 and 3 degrees of freedom. The device was subjected to regular waves and included a simple model of viscous drag. The bistable mechanism was provided by a magnetic dipole model quantified by a dimensionless parameter applicable to any bistable system. The performance of the device was is assessed by the theoretical power generated. Over each model, the previously observed benefit of bistability was not consistently obtained. Simulations of regular waves demonstrated an increase in generated power for suboptimal conditions for some frequencies, while a reduction in generated power was observed in optimal conditions. The performance increase showed strong correlation to the phase relationship between the motion and exciting forces as a result of bistability.