|
Titel |
Modulational instability and wave amplification in finite water depth |
VerfasserIn |
L. Fernandez, M. Onorato, J. Monbaliu, A. Toffoli |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
1561-8633
|
Digitales Dokument |
URL |
Erschienen |
In: Natural Hazards and Earth System Sciences ; 14, no. 3 ; Nr. 14, no. 3 (2014-03-27), S.705-711 |
Datensatznummer |
250118342
|
Publikation (Nr.) |
copernicus.org/nhess-14-705-2014.pdf |
|
|
|
Zusammenfassung |
The modulational instability of a uniform wave train to side band
perturbations is one of the most plausible mechanisms for the generation of
rogue waves in deep water. In a condition of finite water depth, however, the
interaction with the sea floor generates a wave-induced current that
subtracts energy from the wave field and consequently attenuates the
instability mechanism. As a result, a plane wave remains stable under the
influence of collinear side bands for relative depths kh ≤ 1.36 (where k
is the wavenumber of the plane wave and h is the water depth), but it can
still destabilise due to oblique perturbations. Using direct numerical
simulations of the Euler equations, it is here demonstrated that oblique side
bands are capable of triggering modulational instability and eventually
leading to the formation of rogue waves also for kh ≤ 1.36. Results,
nonetheless, indicate that modulational instability cannot sustain a
substantial wave growth for kh < 0.8. |
|
|
Teil von |
|
|
|
|
|
|