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Resonant amplification of gravity waves over a circular sill

Published online by Cambridge University Press:  21 April 2006

John W. Miles
Affiliation:
Institute of Geophysics and Planetary Physics, University of California, San Diego,La Jolla, CA 92093, USA

Abstract

The trapping of gravity waves over a circular sill, originally studied by Longuet-Higgins (1967), is re-examined in the limit δ ≡ dl/d ↓ 0 with λ ≡ σ2d/g = O(1), where d1 is the depth over the sill, d the outer depth, and a the angular frequency of the incident wave. Explicit results are obtained for the resonance curves. These results are in qualitative agreement with the corresponding shallow-water approximations (Λ [Lt ] 1) of Longuet-Higgins, which have been questioned by Renardy (1983). A remarkably simple result is obtained for the mean-square response to a broadband, randomly phased incident wave.

Type
Research Article
Copyright
© 1986 Cambridge University Press

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References

Barnard, B. J. S., Pritchard, W. G. & PrOVIS, P. G. 1983 Experiments on wave trapping by a submerged cylindrical island. Geophys. Astrophya. Fluid Dyn. 24, 2348.Google Scholar
Black, J. L., Mei, C. C. & Bray, M. C. G. 1971 Radiation and scattering of water waves by rigid bodies. J. Fluid Mech. 46, 151164.Google Scholar
Longuet-Higgins, M. S. 1967 On the trapping of wave energy round islands. J. Fluid Mech. 29, 781821.Google Scholar
Miles, J. W. 1967a Surface-wave damping in closed basins. Proc. R. Soc. Land. A 297, 459475.Google Scholar
Miles, J. W. 1967b Surface-wave scattering matrix for a shelf. J. Fluid Mech. 28, 755767.Google Scholar
Miles, J. W. 1971 A note on variational principles for surface-wave scattering. J. Fluid Mech. 46, 141149.Google Scholar
Miles, J. & Gilbert, F. 1968 Scattering of gravity waves by a circular dock. J. Fluid Mech. 34, 783793; 46, 149 (Corrigenda).Google Scholar
Morse, P. M. & Feshbach, H. 1953 Methods of Theoretical Physics, vol. 2, p. 1929. McGraw-Hill.
Mangulis, V. 1965 Handbook of Series for Scientists and Engineers. Academic.
Pite, H. D. 1977 The excitation of damped waves diffracted over a submerged circular sill. J. Fluid Mech. 82, 621641.Google Scholar
Renardy, Y. 1983 Trapping of water waves above a round sill. J. Fluid Mech. 132, 105118.Google Scholar