DOI: 10.1029/2017JC013515
Scopus记录号: 2-s2.0-85046108582
论文题名: Interaction of Waves with Idealized High-Relief Bottom Roughness
作者: Yu X. ; Rosman J.H. ; Hench J.L.
刊名: Journal of Geophysical Research: Oceans
ISSN: 21699275
出版年: 2018
卷: 123, 期: 4 起始页码: 3038
结束页码: 3059
语种: 英语
英文关键词: friction factor
; high-relief bottom roughness
; large eddy simulations
Scopus关键词: bottom friction
; coastal zone
; large eddy simulation
; momentum transfer
; Navier-Stokes equations
; oscillating flow
; roughness
; shear stress
; water column
英文摘要: Considerable uncertainty exists about how to represent wave bottom friction in coastal systems like reefs where orbital excursions are similar to roughness element size. Here, interactions between waves and large bottom roughness were investigated using Large Eddy Simulations of oscillatory flow over infinite hemisphere arrays. Wave amplitude, period, and hemisphere spacing were varied to investigate the dependence of kinematics and dynamics on dimensionless parameters. The net effect of topography on the oscillatory flow was assessed using a spatially and phase-averaged Navier-Stokes framework. Dynamics depended strongly on Keulegan-Carpenter number (KC), the ratio of wave orbital excursion to roughness element size. For 1 < KC < 10, flow separation was weak, form drag was small, stress gradients were negligible, and the main effect of topography on the flow was the inertial force associated with acceleration around roughness elements. For 10 < KC < 20, strong flow separation occurred, and both drag and inertial forces were important. Phase-dependent dispersive stresses were the main mechanism for vertical momentum transfer between the canopy layer and the overlying water column. Friction factors based on the drag force increased with KC for 1 < KC < 20, different from previously proposed empirical curves, but approached these curves for high KC. Friction factors based on the total force decreased with increasing KC and were consistent with previously proposed curves. These results highlight the importance of distinguishing the total force on the bottom, the drag force that removes energy from the flow, and the shear stress above the canopy layer, which were very different for the parameter range in this study. © 2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/114164
Appears in Collections: 气候减缓与适应
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作者单位: Engineering School of Sustainable Infrastructure & Environment, University of Florida, Gainesville, FL, United States; Institute of Marine Sciences, University of North Carolina at Chapel Hill, Morehead City, NC, United States; Marine Laboratory, Nicholas School of the Environment, Duke University, Beaufort, NC, United States
Recommended Citation:
Yu X.,Rosman J.H.,Hench J.L.. Interaction of Waves with Idealized High-Relief Bottom Roughness[J]. Journal of Geophysical Research: Oceans,2018-01-01,123(4)