Large-scale laboratory study of breaking wave hydrodynamics over a fixed bar

Dominic A. van der A, Joep van der Zanden, Tom O'Donoghue, David Hurther, Iván Cáceres, Stuart J. McLelland, Jan S. Ribberink

Research output: Contribution to journalArticleAcademicpeer-review

19 Citations (Scopus)
113 Downloads (Pure)

Abstract

A large-scale wave flume experiment has been carried out involving a T = 4 s regular wave with H = 0.85 m wave height plunging over a fixed barred beach profile. Velocity profiles were measured at 12 locations along the breaker bar using LDA and ADV. A strong undertow is generated reaching magnitudes of 0.8 m/s on the shoreward side of the breaker bar. A circulation pattern occurs between the breaking area and the inner surf zone. Time-averaged turbulent kinetic energy (TKE) is largest in the breaking area on the shoreward side of the bar where the plunging jet penetrates the water column. At this location, and on the bar crest, TKE generated at the water surface in the breaking process reaches the bottom boundary layer. In the breaking area, TKE does not reduce to zero within a wave cycle which leads to a high level of “residual” turbulence and therefore lower temporal variation in TKE compared to previous studies of breaking waves on plane beach slopes. It is argued that this residual turbulence results from the breaker bar-trough geometry, which enables larger length scales and time scales of breaking-generated vortices and which enhances turbulence production within the water column compared to plane beaches. Transport of TKE is dominated by the undertow-related flux, whereas the wave-related and turbulent fluxes are approximately an order of magnitude smaller. Turbulence production and dissipation are largest in the breaker zone and of similar magnitude, but in the shoaling zone and inner surf zone production is negligible and dissipation dominates.
Original languageEnglish
Pages (from-to)3287-3310
Number of pages24
JournalJournal of geophysical research : Oceans
Volume122
Issue number4
DOIs
Publication statusPublished - 2017

Fingerprint

breaking wave
kinetic energy
hydrodynamics
surf zone
turbulence
undertow
dissipation
beach
water column
beach profile
flume experiment
benthic boundary layer
wave height
velocity profile
vortex
trough
temporal variation
laboratory
timescale
surface water

Cite this

van der A, D. A., van der Zanden, J., O'Donoghue, T., Hurther, D., Cáceres, I., McLelland, S. J., & Ribberink, J. S. (2017). Large-scale laboratory study of breaking wave hydrodynamics over a fixed bar. Journal of geophysical research : Oceans, 122(4), 3287-3310. https://doi.org/10.1002/2016jc012072
van der A, Dominic A. ; van der Zanden, Joep ; O'Donoghue, Tom ; Hurther, David ; Cáceres, Iván ; McLelland, Stuart J. ; Ribberink, Jan S. / Large-scale laboratory study of breaking wave hydrodynamics over a fixed bar. In: Journal of geophysical research : Oceans. 2017 ; Vol. 122, No. 4. pp. 3287-3310.
@article{d8f479de11154eb38b265f10fa4b5ca3,
title = "Large-scale laboratory study of breaking wave hydrodynamics over a fixed bar",
abstract = "A large-scale wave flume experiment has been carried out involving a T = 4 s regular wave with H = 0.85 m wave height plunging over a fixed barred beach profile. Velocity profiles were measured at 12 locations along the breaker bar using LDA and ADV. A strong undertow is generated reaching magnitudes of 0.8 m/s on the shoreward side of the breaker bar. A circulation pattern occurs between the breaking area and the inner surf zone. Time-averaged turbulent kinetic energy (TKE) is largest in the breaking area on the shoreward side of the bar where the plunging jet penetrates the water column. At this location, and on the bar crest, TKE generated at the water surface in the breaking process reaches the bottom boundary layer. In the breaking area, TKE does not reduce to zero within a wave cycle which leads to a high level of “residual” turbulence and therefore lower temporal variation in TKE compared to previous studies of breaking waves on plane beach slopes. It is argued that this residual turbulence results from the breaker bar-trough geometry, which enables larger length scales and time scales of breaking-generated vortices and which enhances turbulence production within the water column compared to plane beaches. Transport of TKE is dominated by the undertow-related flux, whereas the wave-related and turbulent fluxes are approximately an order of magnitude smaller. Turbulence production and dissipation are largest in the breaker zone and of similar magnitude, but in the shoaling zone and inner surf zone production is negligible and dissipation dominates.",
author = "{van der A}, {Dominic A.} and {van der Zanden}, Joep and Tom O'Donoghue and David Hurther and Iv{\'a}n C{\'a}ceres and McLelland, {Stuart J.} and Ribberink, {Jan S.}",
year = "2017",
doi = "10.1002/2016jc012072",
language = "English",
volume = "122",
pages = "3287--3310",
journal = "Journal of geophysical research : Oceans",
issn = "2169-9275",
publisher = "Wiley-Blackwell",
number = "4",

}

van der A, DA, van der Zanden, J, O'Donoghue, T, Hurther, D, Cáceres, I, McLelland, SJ & Ribberink, JS 2017, 'Large-scale laboratory study of breaking wave hydrodynamics over a fixed bar' Journal of geophysical research : Oceans, vol. 122, no. 4, pp. 3287-3310. https://doi.org/10.1002/2016jc012072

Large-scale laboratory study of breaking wave hydrodynamics over a fixed bar. / van der A, Dominic A.; van der Zanden, Joep ; O'Donoghue, Tom; Hurther, David; Cáceres, Iván; McLelland, Stuart J.; Ribberink, Jan S.

In: Journal of geophysical research : Oceans, Vol. 122, No. 4, 2017, p. 3287-3310.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Large-scale laboratory study of breaking wave hydrodynamics over a fixed bar

AU - van der A, Dominic A.

AU - van der Zanden, Joep

AU - O'Donoghue, Tom

AU - Hurther, David

AU - Cáceres, Iván

AU - McLelland, Stuart J.

AU - Ribberink, Jan S.

PY - 2017

Y1 - 2017

N2 - A large-scale wave flume experiment has been carried out involving a T = 4 s regular wave with H = 0.85 m wave height plunging over a fixed barred beach profile. Velocity profiles were measured at 12 locations along the breaker bar using LDA and ADV. A strong undertow is generated reaching magnitudes of 0.8 m/s on the shoreward side of the breaker bar. A circulation pattern occurs between the breaking area and the inner surf zone. Time-averaged turbulent kinetic energy (TKE) is largest in the breaking area on the shoreward side of the bar where the plunging jet penetrates the water column. At this location, and on the bar crest, TKE generated at the water surface in the breaking process reaches the bottom boundary layer. In the breaking area, TKE does not reduce to zero within a wave cycle which leads to a high level of “residual” turbulence and therefore lower temporal variation in TKE compared to previous studies of breaking waves on plane beach slopes. It is argued that this residual turbulence results from the breaker bar-trough geometry, which enables larger length scales and time scales of breaking-generated vortices and which enhances turbulence production within the water column compared to plane beaches. Transport of TKE is dominated by the undertow-related flux, whereas the wave-related and turbulent fluxes are approximately an order of magnitude smaller. Turbulence production and dissipation are largest in the breaker zone and of similar magnitude, but in the shoaling zone and inner surf zone production is negligible and dissipation dominates.

AB - A large-scale wave flume experiment has been carried out involving a T = 4 s regular wave with H = 0.85 m wave height plunging over a fixed barred beach profile. Velocity profiles were measured at 12 locations along the breaker bar using LDA and ADV. A strong undertow is generated reaching magnitudes of 0.8 m/s on the shoreward side of the breaker bar. A circulation pattern occurs between the breaking area and the inner surf zone. Time-averaged turbulent kinetic energy (TKE) is largest in the breaking area on the shoreward side of the bar where the plunging jet penetrates the water column. At this location, and on the bar crest, TKE generated at the water surface in the breaking process reaches the bottom boundary layer. In the breaking area, TKE does not reduce to zero within a wave cycle which leads to a high level of “residual” turbulence and therefore lower temporal variation in TKE compared to previous studies of breaking waves on plane beach slopes. It is argued that this residual turbulence results from the breaker bar-trough geometry, which enables larger length scales and time scales of breaking-generated vortices and which enhances turbulence production within the water column compared to plane beaches. Transport of TKE is dominated by the undertow-related flux, whereas the wave-related and turbulent fluxes are approximately an order of magnitude smaller. Turbulence production and dissipation are largest in the breaker zone and of similar magnitude, but in the shoaling zone and inner surf zone production is negligible and dissipation dominates.

U2 - 10.1002/2016jc012072

DO - 10.1002/2016jc012072

M3 - Article

VL - 122

SP - 3287

EP - 3310

JO - Journal of geophysical research : Oceans

JF - Journal of geophysical research : Oceans

SN - 2169-9275

IS - 4

ER -

van der A DA, van der Zanden J, O'Donoghue T, Hurther D, Cáceres I, McLelland SJ et al. Large-scale laboratory study of breaking wave hydrodynamics over a fixed bar. Journal of geophysical research : Oceans. 2017;122(4):3287-3310. https://doi.org/10.1002/2016jc012072