Observation of resonant interactions among surface gravity waves

Félicien Bonnefoy (1) , Florence Haudin (2) , Guillaume Michel (3) , Benoît Semin (3) , Thomas Humbert (4) , Sébastien Aumaître (4) , Michael Berhanu (2) , Eric Falcon (2)

1 LHEEA - Laboratoire de recherche en Hydrodynamique, Énergétique et Environnement Atmosphérique
2 MSC - Matière et Systèmes Complexes
3 LPS - Laboratoire de Physique Statistique de l'ENS
4 SPHYNX - Systèmes Physiques Hors-équilibre, hYdrodynamique, éNergie et compleXes

We experimentally study resonant interactions of oblique surface gravity waves in a large basin. Our results strongly extend previous experimental results performed mainly for perpendicular or collinear wave trains. We generate two oblique waves crossing at an acute angle, while we control their frequency ratio, steepnesses and directions. These mother waves mutually interact and give birth to a resonant wave whose properties (growth rate, resonant response curve and phase locking) are fully characterized. All our experimental results are found in good quantitative agreement with four-wave interaction theory with no fitting parameter. Off-resonance experiments are also reported and the relevant theoretical analysis is conducted and validated.

Mots clés: surface gravity waves; waves/free-surface flows; weakly nonlinear interaction; four-wave interaction

Domaines: Mécanique des fluides [physics.class-ph]; Dynamique des Fluides [physics.flu-dyn]

Félicien Bonnefoy, Florence Haudin, Guillaume Michel, Benoît Semin, Thomas Humbert, et al.. Observation of resonant interactions among surface gravity waves. Journal of Fluid Mechanics, 2016, 805, ⟨10.1017/jfm.2016.576⟩. ⟨hal-01341862v2⟩