| Abstract: | The wave-wave kinetic equation for surface gravity waves occurring in a deep sea and a sea of finite depth is solved numerically,
using the Runge-Kutta technique. Spectral evolution was the result only of the waves’ being non-linear, without any contribution
from wave generation and dissipation. The JONSWAP frequency spectra and the angular spectra of various widths were used to
perform calculations. The existence of a steady angular wave spectrum, following its long evolution in a deep sea, has been
confirmed here. For the sea of finite depth, a new result has been obtained. It exhibits the ‘focusing’ of the frequential
and the angular spectra when the wavelength of a harmonic from the spectral maximum equals 2π, of the depth of the sea. With
the depth further decreasing, the wave spectrum swiftly expands. The three-dimensional wave field in a deep sea becomes two-dimensional
in the shallows.
Translated by Vladimir A. Puchkin. |
