Numerical prediction of wave transformation, velocity, and bottom stress in the inner surf and swash zone
Numerical prediction of wave transformation, velocity, and bottom stress in the inner surf and swash zone
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内海浪和斜流区波浪变换、速度和底部应力的数值预测
DOI：
10.1061/40549(276)9
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发表时间：
2001
影响因子：
--
通讯作者：
William Hobensack
中科院分区：
文献类型：
--
作者：
William Hobensack
在窄波水槽中进行了物理模型研究，以验证先前建立的预测粗糙不透水坡面上不规则波的水动力响应的数值模型。在物理模型研究中，使用窄带状TMA谱和粗糙的不透水复合坡度来运行一个案例。复合边坡由1：10的坡度和1：35的坡度组成。入射波和反射波在沿1：35斜率的13个位置使用三个量规阵列进行了分辨。此外，还在15个位置沿1：10斜率测量了自由面。用三个电容式日出观测仪垂直叠加，测量了水线沿1：10坡度的摆动。此外，还使用激光多普勒测速仪(LDV)测量了沿1：10斜率的11个水平位置的几个海拔高度的速度。结果表明，在冲浪带内，岸上和离岸流动的许多阶段都存在对数分布。在冲激区内，对数剖面在离岸流动过程中建立得更清楚。将实测的水动力响应与计算的水动力响应进行了比较，以评价该模型对湍流区陡坡水流的预报能力。在数值模式的向海边界指定了两个位置的入射波时间序列。绘制了向海边界反射波时间序列和坡面水线振荡时间序列的实测值和计算值。该模型能够预报波浪在粗糙不透水坡面上的详细时变量，以及波浪反射、日出和流速的一般波动特征，表明该模型可以用来预报湍流区的水动力。该模型对摩擦因数沿1：10斜率的变化有很强的敏感性。为了更好地预测冲浪区的床面应力，需要改进底摩擦系数的估计。
A physical model study was conducted in a narrow wave flume to verify a previously developed numerical model for predicting the hydrodynamic response to irregular waves on a rough impermeable slope. In the physical model study, one case was run using a narrow banded TMA spectrum and a rough impermeable composite slope. The composite slope consisted of a 1:10 slope fronted by a 1:35 slope. The incident and reflected waves were resolved at 13 locations along the 1:35 slope using a three gage array. In addition, the free surface was measured along the 1:10 slope at 15 locations. A vertical stack of three capacitance sunup gages was used to measure the waterline oscillation along the 1:10 slope. Also, velocities were measured using a laser Doppler velocimeter (LDV) at 11 horizontal locations along the 1:10 slope at several elevations. A logarithmic profile was shown to exist for many phases of the onshore and offshore flows in the surf zone. Inside the swash zone, the logarithmic profile was more clearly established during the offshore flow. The measured and computed hydrodynamic responses were compared to evaluate the capability of the model in predicting the flow on a rough slope in the swash zone. The incident wave time series at two locations was specified at the seaward boundary of the numerical model. The measured and computed time series of both the reflected wave time series at the seaward boundary and the water line oscillation on the slope were plotted. The ability of the model to predict the detailed time varying quantities as well as the general wave characteristics of wave reflection, sunup, and flow velocity on the rough impermeable slope indicate that the model could be used to predict the swash zone hydrodynamics. The model showed a strong sensitivity to changes in the friction factor along the 1:10 slope. Improvements in the estimation of the bottom friction factor are needed to better predict the bed stress in the swash zone.