Contributions to the wave-mean momentum balance in the surf zone
| Autor: | Marien Boers, Wouter Kranenburg, Jebbe J. van der Werf, Kevin Neessen, Jan S. Ribberink |
|---|---|
| Přispěvatelé: | Marine and Fluvial Systems |
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Environmental Engineering
010504 meteorology & atmospheric sciences Ocean Engineering Mechanics Reynolds stress 01 natural sciences 010305 fluids & plasmas Physics::Fluid Dynamics Undertow Wave flume 0103 physical sciences 2023 OA procedure Shear stress Crest Geotechnical engineering Mean flow Radiation stress Wave setup Geology 0105 earth and related environmental sciences |
| Zdroj: | Coastal engineering, 121, 212-220. Elsevier |
| ISSN: | 0378-3839 |
| Popis: | Mean (wave-averaged) cross-shore flow in the surfzone has a strong vertical variation. Good understanding and prediction of this mean velocity profile is of crucial importance, as it determines the advective transport of constituents, such as sediment, and consequently the coastal morphological evolution. Most modeling systems for coastal hydrodynamics and morphodynamics do no resolve the wave motion, and wave-current coupling is a challenging topic. This paper investigates stresses and forces that control mean surfzone hydrodynamics based on detailed wave flume velocity measurements above a fixed sloping bed including two breaker bars. The data show that the vertical distribution of normal stress below the wave trough level is fairly uniform. At the same time, the data suggest that a significant part is concentrated between the wave trough and crest level. Furthermore, it is concluded that the horizontal radiation stress gradients and the vertical shear stress gradients can be of the same order of magnitude in the vicinity of the breaker bar. Although usually ignored in 3D mean flow modeling systems, the wave Reynolds stress makes an important contribution to the mean shear stress. The normal stress below the wave trough level could be reasonably well predicted using the classical [16] expression, accounting for the contribution between wave crest and trough. The model of [39] reproduces the main trends in the wave Reynolds stresses above the bottom boundary layer. |
| Databáze: | OpenAIRE |
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