Browse > Article
http://dx.doi.org/10.2478/IJNAOE-2013-0157

Heaving displacement amplification characteristics of a power buoy in shoaling water with insufficient draft  

Kweon, Hyuck-Min (Department of Railway Construction and Environmental Engineering, Gyeongju University)
Cho, Il-Hyoung (Department of Ocean System Engineering, Jeju National University)
Cho, Hong-Yeon (Principal Research Scientist, Marine Environments & Conservation Research Department, Korea Institute of Ocean Science & Technology)
Publication Information
International Journal of Naval Architecture and Ocean Engineering / v.5, no.4, 2013 , pp. 614-624 More about this Journal
Abstract
The resonance power buoy is a convincing tool that can increase the extraction efficiency of wave energy. The buoy needs a corresponding draft, to move in resonance with waves within the peak frequency band where wave energy is concentrated. However, it must still be clarified if the buoy acts as an effective displacement amplifier, when there is insufficient water depth. In this study, the vertical displacement of a circular cylinder-type buoy was calculated, with the spectrum data observed in a real shallow sea as the external wave force, and with the corresponding draft, according to the mode frequency of normal waves. Such numerical investigation result, without considering Power Take-Off (PTO) damping, confirmed that the area of the heave responses spectrum can be amplified by up to about tenfold, compared with the wave energy spectrum, if the draft corresponds to the peak frequency, even with insufficient water depth. Moreover, the amplification factor of the buoy varied, according to the seasonal changes in the wave spectra.
Keywords
Resonance power buoy; Energy extraction efficiency; Draft depth; Mode frequency; PTO;
Citations & Related Records
Times Cited By KSCI : 3  (Citation Analysis)
연도 인용수 순위
1 Budal, K. and Falnes, J., 1975. A resonant point absorber of ocean wave power. Nature, 256, pp.478-479.   DOI   ScienceOn
2 Cho, I.H., Kim, M.H., Kweon, H.M., 2012.Wave energy converter by using relative heave motion between buoy and inner dynamic system, Ocean Systems Engineering, 2(4), pp.297-314.   DOI   ScienceOn
3 Falnes J., 1999. Wave-energy conversion through relative motions between two single-mode oscillating bodies. Journal of Offshore Mechanics and Arctic Engineering, 121, pp.32-38.   DOI   ScienceOn
4 French, M.J., 1979. A generalized view of resonant energy transfer. Journal of Mechanical Engineering Science, 21(4), pp.299-300.   DOI
5 French, M.J. and Bracewell, R.H., 1995. The systematic design of economic wave energy converters. Proceedings of the 5th Offshore and Polar Engineering Conference, ISOPE, Hague, Netherlands, 11-16 June 1995, pp.106-109.
6 Grilli, S.T., Grilli, A.R., Bastien, S.P., Sepe, R.B. and Spaulding, M.L., 2011. Small buoys for energy harvesting: Experimental and numerical model studies. Proceedings of the 21th Offshore and Polar Engineering Conference, ISOPE, Manui, Hawaii, USA, June 19-24 2011, pp.598-605.
7 Kweon, H.M., Cho, H.Y. and Jeong, W.M., 2013b. Wave analysis and spectrum estimation for the optimal design of the wave energy converter in the Hupo coastal sea, Journal of Korean Society of Coastal and Ocean Engineers, 25(3), pp.147-153.   과학기술학회마을   DOI   ScienceOn
8 Kweon, H.M., Koh, H.J., Kim, J.R. and Choi, Y.H., 2013a. Experimental study for the resonance effect of the power buoy amplitude, Journal of the Korean Society of Civil Engineers, 33(2), pp.585-594.   과학기술학회마을   DOI   ScienceOn