Hostname: page-component-78c5997874-4rdpn Total loading time: 0 Render date: 2024-11-10T06:58:29.438Z Has data issue: false hasContentIssue false
  • English
  • Français

Bragg scattering of surface waves by periodic bars: theory and experiment

Published online by Cambridge University Press:  21 April 2006

Tetsu Hara  and
Chiang C. Mei
Tetsu Hara
Affiliation:
Department of Civil Engineering, University of Tokyoand Massachusetts Institute of Technology, Cambridge, MA 02139, USA
Chiang C. Mei
Affiliation:
Department of Civil Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
Get access Rights & Permissions [Opens in a new window]

Abstract

We extend a recent linearized theory on Bragg scattering of surface waves by periodic sandbars to include second-order effects of the free surface and of the bars. New experiments are performed to verify the existence of the cutoff detuning frequency, the dispersive nature of the first-order wave envelope, and the radiation of second-order long waves. Measured transient and quasi-steady responses to incident wave packets and uniform wavetrains are compared with corresponding theoretical results. For quasi-steady incident waves of relatively small steepness it is found necessary to improve the theory to the second order in bar slope, in order that the calculated short-wave envelopes agree with those measured over the bars.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 178 , May 1987 , pp. 221 - 241
Copyright
© 1987 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Davies, A. G. 1982 The reflection of wave energy by undulations on the seabed. Dyn. Atmos. Oceans 6, 207–232.Google Scholar
Davies, A. G. & Heathershaw, A. D. 1984 Surface-wave propagation over sinusoidally varying topography. J. Fluid Mech. 144, 419–443.Google Scholar
Hara, T. 1985 Resonant reflection of water waves by periodic sandbars. Masters thesis, Department of Civil Engineering, University of Tokyo.
Heathershaw, A. D. 1982 Seabed-wave resonance and sandbar growth. Nature 296, 343–345.Google Scholar
Hunt, J. N. 1952 Viscous damping of waves over an inclined bed in a channel of finite width. Houille Blanche 7, 836–842.Google Scholar
Mei, C. C. 1985 Resonant reflection of surface water waves by periodic sandbars. J. Fluid Mech. 152, 315–335.Google Scholar