The dispersion relation for a nonlinear random gravity wave field
- 27 May 1976
- journal article
- research article
- Published by Cambridge University Press (CUP) in Journal of Fluid Mechanics
- Vol. 75 (2) , 337-345
- https://doi.org/10.1017/s0022112076000256
Abstract
The dispersion relation for a random gravity wave field is derived using the complete system of nonlinear equations. It is found that the generally accepted dispersion relation is only a first-order approximation to the mean value. The correction to this approximation is expressed in terms of the energy spectral function of the wave field. The non-zero mean deviation is proportional to the ratio of the mean Eulerian velocity at the surface and the local phase velocity. In addition to the mean deviation, there is a random scatter. The root-mean-square value of this scatter is proportional to the ratio of the root-mean-square surface velocity and the local phase velocity. As for the phase velocity, the nonzero mean deviation is equal to the mean Eulerian velocity while the root-mean-square scatter is equal to the root-mean-square surface velocity. Special cases are considered and a comparison with experimental data is also discussed.Keywords
This publication has 2 references indexed in Scilit:
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- The Dynamics of the Upper Ocean. By O. M. Phillips. Pp. vii + 261. 60s. 1966. (Cambridge.)The Mathematical Gazette, 1968