Vorticity generation by short‐crested wave breaking

David B. Clark; Steve Elgar; Britt Raubenheimer

doi:10.1029/2012gl054034

SPH MODELING OF VORTICITY GENERATION BY SHORT-CRESTED WAVE BREAKING

Coastal Engineering Proceedings ◽

10.9753/icce.v35.waves.1 ◽

2017 ◽

pp. 1 ◽

Cited By ~ 1

Author(s):

Zhangping Wei ◽

Robert A Dalrymple

Keyword(s):

Incident Wave ◽

Wave Breaking ◽

Circulation Pattern ◽

Breaking Wave ◽

Mesh Free ◽

Wave Basin ◽

Particle Hydrodynamics ◽

Smoothed Particle ◽

Vorticity Generation ◽

Incident Waves

This study investigates vorticity generation by short-crested wave breaking by using the mesh-free Smoothed Particle Hydrodynamics model, GPUSPH. The short-crested waves are created by generating intersecting wave trains in a numerical wave basin with a beach. The capability of GPUSPH to simulate short-crested waves is first validated by laboratory measurements. Then we examine short-crested wave breaking with two incident wave heights H = 0.2 m and 0.3 m. The larger incident wave breaks at the toe of the planar beach, while the smaller incident wave breaks above the planar beach. The breaking wave profile, current field, nearshore circulation pattern, and vertical vorticity field due to short-crested wave breaking are carefully compared between two incident waves.

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BORE-INDUCED MACROVORTICES OVER A PLANAR BEACH: THE CROSS-SEA CONDITION CASE

Coastal Engineering Proceedings ◽

10.9753/icce.v33.waves.18 ◽

2012 ◽

Vol 1 (33) ◽

pp. 18

Author(s):

Matteo Postacchini ◽

Maurizio Brocchini ◽

Luciano Soldini

Keyword(s):

Shallow Water Equations ◽

Wave Breaking ◽

Ad Hoc ◽

Rip Currents ◽

Positive Interaction ◽

Wave Ray ◽

Nonlinear Shallow Water Equations ◽

Fair Comparison ◽

Wave Trains ◽

Vorticity Generation

Wave breaking over submerged topographic obstacles leads to vorticity generation and, at times, to the generation of strong offshore-directed rip currents. The generation of finite-length breakers may also be induced by the positive interaction of wave trains propagating to shore with a relative angle. Such an interaction gives rise to a short-crested system, this, in turn, generating both breakers of finite crossflow length and an intense associated vorticity. We here analyze such a vorticity generation mechanism specifically focusing on the location where wave breaking occurs. To this purpose we use both a simple theoretical approach, based on the well-known theory of wave ray propagation, and ad-hoc numerical simulations, by means of a NSWE (Nonlinear Shallow Water Equations) solver. A fair comparison between such preliminary theoretical and numerical results suggests that the present work can be used as the basis for future analyses of vorticity generation by cross seas.

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Wave Breaking under Storm Condition

Coastal Engineering 1994 ◽

10.1061/9780784400890.026 ◽

1995 ◽

Author(s):

Yoshiaki Kawata

Keyword(s):

Wave Breaking ◽

Storm Condition

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PHYSICAL INTERPRETATION OF WAVE BREAKING CRITERIA

Proceedings of International Conference "Managinag risks to coastal regions and communities in a changinag world" (EMECS'11 - SeaCoasts XXVI) ◽

10.31519/conferencearticle_5b1b94019210f7.30842240 ◽

2017 ◽

Author(s):

Sergey Kuznetsov ◽

Yana Saprykina ◽

Boris Divinskiy ◽

...

Keyword(s):

Nonlinear Wave ◽

Wave Breaking ◽

Second Harmonic ◽

Vertical Axis ◽

Breaking Waves ◽

Wave Transformation ◽

Spectral Structure ◽

Similarity Parameter ◽

Nonlinear Harmonics ◽

The Waves

On the base of experimental data it was revealed that type of wave breaking depends on wave asymmetry against the vertical axis at wave breaking point. The asymmetry of waves is defined by spectral structure of waves: by the ratio between amplitudes of first and second nonlinear harmonics and by phase shift between them. The relative position of nonlinear harmonics is defined by a stage of nonlinear wave transformation and the direction of energy transfer between the first and second harmonics. The value of amplitude of the second nonlinear harmonic in comparing with first harmonic is significantly more in waves, breaking by spilling type, than in waves breaking by plunging type. The waves, breaking by plunging type, have the crest of second harmonic shifted forward to one of the first harmonic, so the waves have "saw-tooth" shape asymmetrical to vertical axis. In the waves, breaking by spilling type, the crests of harmonic coincides and these waves are symmetric against the vertical axis. It was found that limit height of breaking waves in empirical criteria depends on type of wave breaking, spectral peak period and a relation between wave energy of main and second nonlinear wave harmonics. It also depends on surf similarity parameter defining conditions of nonlinear wave transformations above inclined bottom.

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