An experimental comparison of velocities underneath focussed breaking waves. (1st May 2018)

• Record Type: Journal Article
• Authors: Alberello, Alberto; Chabchoub, Amin; Monty, Jason P.; Nelli, Filippo; Lee, Jung Hoon; Elsnab, John; Toffoli, Alessandro
• Is Part Of: Ocean engineering. Volume 155(2018)
• Page Start: 201
• Page End: 210
• Publication Date: 2018-05-01
• Subjects: Waves -- Surface gravity waves -- Wave focussing -- Velocity -- Kinematics -- Wave breaking; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2018.02.049
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: Nonlinear wave interactions affect the evolution of steep wave groups, their breaking and the associated kinematic field. Laboratory experiments are performed to investigate the effect of the underlying focussing mechanism on the shape of the breaking wave and its velocity field. In this regard, it is found that the shape of the wave spectrum plays a substantial role. Broader underlying wave spectra leads to energetic plungers at a relatively low amplitude. For narrower spectra waves break at higher amplitudes but with a less energetic spiller. Comparison with standard engineering methods commonly used to predict the velocity underneath extreme waves shows that, under certain conditions, the measured velocity profile strongly deviates from engineering predictions. Highlights: The effect of the underlying focussing mechanism on the shape of the breaking wave and its velocity field is investigated. Dispersive focussing and Nonlinear Schrödinger framework are used to generate a breaking rogue waves. Wave velocities (PIV) are compared with standard engineering models.