Observations of swash zone velocities: A note on friction coefficients
Observations of swash zone velocities: A note on friction coefficients
复制标题
斜盘区速度的观察：关于摩擦系数的注释
DOI：
--
复制
发表时间：
2004
期刊：
影响因子：
--
通讯作者：
R. Guza
中科院分区：
文献类型：
--
作者：
B. Raubenheimer;S. Elgar;R. Guza
[1]利用在低坡度、细粒桑迪海滩上观察到的跨岸流体速度[Raubenheimer，2002]估算了冲刷区的垂直流结构和湍流耗散，两组三个流速计分别位于海床上方约2、5和8 cm处。的意见是一致的，在5厘米的床波轨道速度的近似对数垂直衰减。相关的摩擦系数是相似的上升流和下降流，在以前的实验室结果。从速度谱估计的湍流耗散率增加，从O（400 cm 2/s3）的内碎波区的O（1000 cm 2/s3）的冲流区的水深减少。在斜流内部的摩擦系数估计与对数模型和独立估计的假设，湍流耗散是平衡的生产从垂直剪切的本地平均流量和波浪破碎是在0.02和0.06之间。这些值是类似的摩擦系数（0.02-0.05）的范围内最近估计的不渗透，粗糙，nonerodibible实验室海滩和摩擦系数（0.01-0.03）的范围内先前估计从现场观察的运动的shoreward边缘的冲流（运行）。
[1] Vertical flow structure and turbulent dissipation in the swash zone are estimated using cross-shore fluid velocities observed on a low-sloped, fine-grained sandy beach [Raubenheimer, 2002] with two stacks of three current meters located about 2, 5, and 8 cm above the bed. The observations are consistent with an approximately logarithmic vertical decay of wave orbital velocities within 5 cm of the bed. The associated friction coefficients are similar in both the uprush and downrush, as in previous laboratory results. Turbulent dissipation rates estimated from velocity spectra increase with decreasing water depth from O(400 cm2/s3) in the inner surf zone to O(1000 cm2/s3) in the swash zone. Friction coefficients in the swash interior estimated with the logarithmic model and independently estimated by assuming that turbulent dissipation is balanced by production from vertical shear of the local mean flow and from wave breaking are between 0.02 and 0.06. These values are similar to the range of friction coefficients (0.02–0.05) recently estimated on impermeable, rough, nonerodible laboratory beaches and to the range of friction coefficients (0.01–0.03) previously estimated from field observations of the motion of the shoreward edge of the swash (run-up).