• Energy Research

Current advances in wave energy technologies have enabled the development of new integrated measurement platforms powered by the energy of wave motion. Instrumentation is now being deployed for the long-term observation of the coastal ocean, with the objectives of analyzing the performance of wave energy converters (WECs) and studying their interactions with the surrounding environment and marine life. In this work, we present the most relevant findings of the installation and initial operation of the Open Sea Lab (OSL), the first coastal observatory in Latin America powered entirely by a WEC device. We evaluated the preliminary data regarding the combined operation of the system, the generation of energy, and the observations obtained by the continuous monitoring of physical variables at the site. The data showed the seasonal variability of the energy produced by the WEC for a range of wave heights during the period of observation. We also investigated the rapid development of biofouling on mooring lines, junction boxes, and other parts of the system, which is characteristic of the settlement and growth of organisms in this ocean region. These analyses show how this new facility will advance our understanding of the coastal environment in the south Pacific Ocean and foster new interdisciplinary collaborations addressing environmental and technical challenges, thereby contributing to the development of wave energy on the continent.

Abstract The current work presents a novel way to evaluate the interaction effects in a diffuser-augmented hydrokinetic turbine (DAHT) under the terms presented on the generalized actuator disc theory described by Jamieson (2011). Transient RANS CFD methods are employed to obtain the performance, thrust, and average flow speeds at the turbine plane in simulations performed in three comparable cases: bare turbine, bare diffuser and diffuser-augmented turbine. After validating the bare turbine case comparing numerical results against the experiments presented by Fontaine et al. (2013), the axial induction factors are obtained for the three cases based on the average speeds of the turbine plane. The analysis of the results shows the importance of considering rotor-diffuser interaction for the design of diffuser-augmented devices, and that these interaction effects are just as relevant as the bare diffuser and the bare turbine characteristics.

Abstract In the present paper, the development of a model scale Wave Energy Converter (WEC) and an experimental WEC test rig are presented, and results of numerical simulations and experimental measurements are shown. The presented point absorber WEC is coupled to a generic power take-off (PTO) and is restricted to pure heave motion in regular waves. Experiments were carried out at the Universidad Austral de Chile (UACh) Wave Tank and results from responses and efficiencies were compared with data from the BEM (boundary element method) code WAMIT. Numerical and experimental results showed good agreement. Finally, results were extrapolated and superposed with typical wave energy spectra found in different Chilean regions, providing a first performance estimation for a wave energy converter in Chile. Results are discussed and compared with an existing technology and give an insight of the potential for wave energy technologies in Chile. Further investigation is proposed for an analysis in irregular waves and the use of a more advanced PTO (power take-off) in the future.