Experimental Study on Interaction Between Degrees of Freedom in a Wave Buoy
- 10 Downloads
Abstract
Increasing degrees of freedom (DOFs) is a useful way to raise the power capture efficiency of oscillating wave energy converters. Thus, this study proposes a buoy with three DOFs, which are surge, heave, and pitch. The hydrodynamic performance and power capture efficiency of the buoy is physically modeled. Amplitudes of unidirectional and coupled motions are compared to analyze the interaction effect between freedoms under conditions with and without power take-off damping. The capture width ratio and corresponding growth rates are also calculated. Results show that the buoy makes a periodic sinusoidal (or approximate) movement in every DOF. Coupling effect can cause an increase in the amplitude in one DOF and a decrease in the amplitudes of the others. This phenomenon shows that the kinematic energy of the buoy redistributes to all DOFs compared with the unidirectional conditions. Adding DOFs can improve the power absorption of the buoy in most cases, but the number of DOFs is not the more the better.
Key words
wave energy oscillating buoy multiple degrees of freedomPreview
Unable to display preview. Download preview PDF.
Notes
Acknowledgements
The authors are grateful for the support of the National Key R&D Program of China (No. 2018YFB1501900), the National Natural Science Fund of China (No. 41706100), the Shandong Provincial Natural Science Key Basic Program (No. ZR2017ZA0202), the Special Projects for Marine Renewable Energy (No. GHME2016YY02), the Shandong Provincial Key Laboratory of Ocean Engineering, and the Qingdao Municipal Key Laboratory of Ocean Renewable Energy.
References
- Albatern Wave Energy, 2017. How WaveNET works. Available at: http://albatern.co.uk/wavenet/works/.
- Babarit, A., Hals, J., Muliawan, M. J., Kurniawan, A., Moan, T., and Krokstad, J., 2012. Numerical benchmarking study of a selection of wave energy converters. Renewable Energy, 41: 44–63.CrossRefGoogle Scholar
- Budal, K., and Falnes, J., 1982. The Norwegian wave-power buoy project. In: The Proceedings of 2nd International Symposium on Wave Energy Utilization. Trondheim, 323–344.Google Scholar
- Carnegie Clean Energy, 2018. What is CETO. Available at: https://www.carnegiece.com/wave/what-is-ceto/.
- Chandrasekaran, S., and Raghavi, B., 2015. Design, development and experimentation of deep ocean wave energy converter system. Energy Procedia, 79: 634–640.CrossRefGoogle Scholar
- Cho, I. H., and Kim, M. H., 2017. Hydrodynamic performance evaluation of a wave energy converter with two concentric vertical cylinders by analytic solutions and model tests. Ocean Engineering, 130: 498–509.CrossRefGoogle Scholar
- Choi, K. S., Yang, D. S., Park, S. Y., and Cho, B. H., 2012. Design and performance test of hydraulic PTO for wave energy converter. International Journal of Precision Engineering & Manufacturing, 13 (5): 795–801.CrossRefGoogle Scholar
- Columbia Power Technology, 2018. How it works. Available at: http://columbiapwr.com/how-it-works/.
- CorPower Ocean AB, 2018. The CorPower wave energy converter. Available at: http://www.corpowerocean.com/corpower-technology/corpower-wave-energy-converter/.
- Cruz, J., 2008. Ocean Wave Energy: Current Status and Future Perspectives. Springer Berlin Heidelberg, Berlin, 287–385.CrossRefGoogle Scholar
- Diamond, C. A., Jude, C. Q., Orazov, B., Savaş, Ö., and O’Reilly, O. M., 2015. Mass-modulation schemes for a class of wave energy converters: Experiments, models, and efficacy. Ocean Engineering, 104: 452–468.CrossRefGoogle Scholar
- Do, H. T., Dinh, Q. T., Nguyen, M. T., Phan, C. B., Dang, T. D., Lee, S., Park, H. G., and Ahn, K. K., 2017. Proposition and experiment of a sliding angle self-tuning wave energy converter. Ocean Engineering, 132: 1–10.CrossRefGoogle Scholar
- Drew, B., Plummer, A. R., and Sahinkaya, M. N., 2009. A review of wave energy converter technology. Proceedings of the Institution of Mechanical Engineers. Part A: Journal of Power and Energy, 223 (8): 887–902.Google Scholar
- Falcão, A. F. O., 2008. Phase control through load control of oscillating-body wave energy converters with hydraulic PTO system. Ocean Engineering, 35 (3): 358–366.CrossRefGoogle Scholar
- Falcão, A. F. O., 2010. Wave energy utilization: A review of the technologies. Renewable & Sustainable Energy Reviews, 14 (3): 899–918.CrossRefGoogle Scholar
- Falnes, J., 2002. Ocean Waves and Oscillating Systems: Linear Interactions Including Wave-Energy Extraction. Cambridge University Press, Cambridge, 196–198.CrossRefGoogle Scholar
- Iijima, T., and Taya, T., 2011. Characteristics of heave & pitch buoy type wave energy converter system. Doboku Gakkai Ronbunshuu B, 16: 239–244.Google Scholar
- Larsson, T. B., and Falnes, J., 2006. Laboratory experiment on heaving body with hydraulic power take-off and latching control. Ocean Engineering, 33 (7): 847–877.CrossRefGoogle Scholar
- Ma, Z., 2013. The study on hydrodynamic performance of oscillating floater buoy wave energy converter. PhD thesis. Ocean University of China.Google Scholar
- Ning, D. Z., Zhao, X. L., Göteman, M., and Kang, H. G., 2016. Hydrodynamic performance of a pile-restrained WEC-type floating breakwater: An experimental study. Renewable Energy, 95: 531–541.CrossRefGoogle Scholar
- Previsic, M., Bedard, R., and Hagerman, G., 2004. E2I EPRI assessment: Offshore wave energy conversion devices, E2I EPRI WP-004-US-Rev1. Electricity Innovation Institute, 1–52.Google Scholar
- Tanaka, H., 1984. Sea trial of a heaving body wave power absorber. Transactions of the Japan Society of Mechanical Engineers B, 50: 2325–2333.CrossRefGoogle Scholar
- Truong, D. Q., and Ahn, K. K., 2014. Development of a novel point absorber in heave for wave energy conversion. Renewable Energy, 65 (5): 183–191.CrossRefGoogle Scholar
- Ulvgård, L., 2017. Wave energy converters: An experimental approach to onshore testing, deployment and offshore monitoring. PhD thesis. Acta Universitatis Upsaliensis Uppsala, Uppsala.Google Scholar
- Weber, J., Mouwen, F., Parish, A., and Robertson, D., 2009. Wavebob-research & development network and tools in the context of systems engineering. Proceedings of 8th European Wave Tidal Energy Conference. Upssala, Sweden, 416–420.Google Scholar
- Wello, 2018. Wello news update. Available at: https://wello.eu/2018/08/10/wello-news-update-august-2018/.
- Zhang, D. H., George, A., Wang, Y. F., Gu, X. X., Li, W., and Chen, Y., 2015. Wave tank experiments on the power capture of a multi-axis wave energy converter. Journal of Marine Science and Technology, 20: 520–529.CrossRefGoogle Scholar
- Zhang, D. H., Li, W., Zhao, H. T., Bao, J. W., and Lin, Y. G., 2014. Design of a hydraulic power take-off system for the wave energy device with an inverse pendulum. China Ocean Engineering, 28: 283–292.CrossRefGoogle Scholar
- Zhao, X. L., and Ning, D. Z., 2018. Experimental investigation of breakwater-type WEC composed of both stationary and floating pontoons. Energy, 155: 226–233.CrossRefGoogle Scholar