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Wave generation by an oscillating surface-pressure and its application in wave-energy extraction

Published online by Cambridge University Press:  20 April 2006

A. J. N. A. Sarmento  and
A. F. de O. Falcão
A. J. N. A. Sarmento
Affiliation:
Mechanical Engineering Department, Instituto Superior Técnico, Universidade Técnica de Lisboa, 1096 Lisboa Codex, Portugal
A. F. de O. Falcão
Affiliation:
Mechanical Engineering Department, Instituto Superior Técnico, Universidade Técnica de Lisboa, 1096 Lisboa Codex, Portugal
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Abstract

A two-dimensional analysis, based on linear surface-wave theory, is developed for an oscillating-water-column wave-energy device in water of arbitrary constant depth. The immersed part of the structure is assumed of shallow draught except for a submerged vertical reflecting wall. Both the cases of linear and nonlinear power take-off are considered. The results show that air compressibility can be important in practice, and its effects may in general be satisfactorily represented by linearization. The analysis indicates that using a turbine whose characteristic exhibits a phase difference between pressure and flow rate may be a method of strongly reducing the chamber length and turbine size with little change in the capability of energy extraction from regular waves. It was found in two examples of devices with strongly nonlinear power take-off that the maximum efficiency is only marginally inferior to what can be achieved in the linear case.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 150 , January 1985 , pp. 467 - 485
Copyright
© 1985 Cambridge University Press

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References

Brown K. M.1973 Computer oriented algorithms for solving systems of simultaneous nonlinear algebraic equations. In Numerical Solution of Systems of Nonlinear Algebraic Equations (ed. G. D. Byrne & C. A. Hall). Academic.
Count B. M., Fry R., Haskell, J. & Jackson N.1981 The M.E.L. oscillating water column. CEGB Rep. RD/M/1157N81.Google Scholar
Evans D. V.1978 The oscillating water column wave-energy device. J. Inst. Maths Applics 22, 423–433.Google Scholar
Evans D. V.1982 Wave-power absorption by systems of oscillating surface pressure distributions. J. Fluid Mech. 114, 481–499.Google Scholar
Fernandes A. C.1983 Analysis of an axisymmetric pneumatic buoy by reciprocity relations and a ring-source method. Ph.D. thesis, Massachusetts Institute of Technology.
Gato, L. M. C. & Falcão A. F. de O.1983 Aerodynamics of self-rectifying turbines for wave-energy extraction (in Portuguese). In Proc. 3rd Portuguese Congr. Theoretical and Applied Mechanics, Lisbon.
Gato, L. M. C. & Falcão A. F. de O.1984 On the theory of the Wells turbine. ASME Paper 84-GT-5; Trans. ASME J: Engng Gas Turbines & Power 106, 628–633.Google Scholar
Lamb H.1905 On deep water waves Proc. Lond. Math. Soc. (2) 2, 371–400.Google Scholar
Mccamy R. C.1961 On the heaving motion of cylinders of shallow draft. J. Ship Res. 5, 34–43.Google Scholar
Moody G. W.1979 The NEL oscillating water column: recent developments. Proc. 1st Symp. Wave Energy Utilization, Gothenburg.
Ogilvie T. F.1969 Oscillating pressure fields on a free surface. Univ. Michigan, Coll. Engng Rep. 030.Google Scholar
Stoker J. J.1957 Water Waves. Interscience.
Wehausen, J. V. & Laitone E. V.1960 Surface waves. In Handbuch der Physik. vol. 9, pp. 446–778. Springer.