Wave Power Extraction by Strip Array of Multiple Buoys

Title & Authors
Wave Power Extraction by Strip Array of Multiple Buoys
Cho, Il-Hyoung;

Abstract
The majority of existing WECs (wave energy converters) are designed to achieve maximum power at a resonance condition. In the case of a single WEC, its size must be large enough for tuning, and it has high efficiency only within a limited frequency band. Recently, wave power extraction by deploying many small buoys in a compact array has been studied under the assumption that the buoy's size and separation distance are much smaller than the water depth, wave length, and size of the array. A boundary value problem involving the macro-scale boundary condition on the mean surface covered by an infinite strip of buoys is solved using the eigenfunction expansion method. The energy extraction efficiency ($\small{{\varepsilon}=1-R^2_f-T^2_r}$), where $\small{R_f}$ and $\small{T_r}$ are the reflection and transmission coefficients for a strip array of buoys, is assessed for various combinations of packing ratio, strip width, and PTO damping coefficient.
Keywords
Wave energy converter;Strip array;Energy extraction efficiency;Eigenfunction expansion method;Heaving buoy;
Language
Korean
Cited by
References
1.
Black, J.L., Mei, C.C., Bray, M.C.G., 1971. Radiation and Scattering of Water Waves by Rigid Bodies. Journal of Fluid Mechanics, 46(1), 151-164.

2.
Budal, K., Falnes, J., 1975. A Resonant Point Absorber of Ocean-Wave Power. Nature, 256, 478-479.

3.
Chamberlain, P.G., 2007. Water Wave Scattering by Finite Arrays of Circular Structures. IMA Journal of Applied Mathematics, 72(1), 52-56.

4.
Child, B.F.M., Venugopal, V., 2010. Optimal Configuration of Wave Energy Device Arrays. Ocean Engineering, 37(16), 1402-1417.

5.
Cho, I.H., 2013. Reflection and Transmission Coefficients by a Surface-Mounted Horizontal Porous Plate. Journal of Korean Society of Coastal and Ocean Engineers, 25(5), 327-334.

6.
Cho, I.H., Kweon, H.M., 2011. Extraction of Wave Energy Using the Coupled Heaving Motion of a Circular Cylinder and Linear Electric Generator, Journal of Ocean Engineering and Technology, 25(6), 9-16.

7.
Cho, I.H., 2014. Wave-Energy Extraction by a Compact Circular Array of Buoys, Journal of Korean Society of Coastal and Ocean Engineers, 26(2), 103-111.

8.
Falcao, A.F. de O., 2002. Wave-Power Absorption by a Periodic Linear Array of Oscillating Water Columns. Ocean Engineering, 29(4), 1164-186.

9.
Falnes, J., 1980. Radiation Impedance Matrix and Optimum Power Absorption for Interacting Oscillators in Surface Waves. Applied Ocean Research, 2, 75-80.

10.
Falnes, J., Budal, K., 1982. Wave-Power Absorption by Parallel Rows of Interacting Oscillating Bodies. Applied Ocean Research, 4(4), 194-207.

11.
Falnes, J., 1984. Wave-Power Absorption by an Array of Attenuators Oscillating with Unconstrained Amplitudes. Applied Ocean Research, 6(1), 16-22.

12.
Garnaud, X., Mei, C.C., 2009a. Wave Power Extraction by a Compact Array of Buoys. Journal of Fluid Mechanics, 635, 389-413.

13.
Garnaud, X., Mei, C.C., 2009b. Comparison of Wave Power Extraction by a Compact Array of Small Buoys and by a Large Buoy. Proceedings of the 8th European Wave and Tidal Energy Conference, Uppsala, Sweden.

14.
Garrett, C.J.R., 1971. Wave Forces on a Circular Dock. Journal of Fluid Mechanics, 46(1), 129-139.

15.
Linton, C.M., Evans, D.V., 1990. The Interaction of Waves with Arrays of Vertical Cylinders. Journal of Fluid Mechanics, 215, 549-69.

16.
Linton, C.M., Mclver, R., 1996. The Scattering of Water Waves by an Array of Circular Cylinders in a Channel. Journal of Engineering Mathematics, 30, 661-82.

17.
Mathews, J.H., Fink, K.K., 2004. Numerical Methods Using Matlab. 4th Edition, Prentice-Hall Inc.

18.
Yeung, R.W., 1981. Added Mass and Damping of a Vertical Cylinder in Finite-Depth Waters. Applied Ocean Research, 3, 119-133.

19.
Zhao, F.F., Bao, W.G., Kinoshita T., Itakura, H., 2010. Interaction of Waves and a Porous Cylinder with an Inner Horizontal Porous Plate. Applied Ocean Research, 32, 252-259.