Oscillatory flows around a headland by 3D modelling with hydrostatic pressure and implicit bed shear stress comparing with experiment and depth-averaged modelling
Oscillatory flows around a headland by 3D modelling with hydrostatic pressure and implicit bed shear stress comparing with experiment and depth-averaged modelling
复制标题
通过使用静水压力和隐式床剪应力的 3D 建模，与实验和深度平均建模进行比较，得到岬角周围的振荡流
DOI：
10.1016/j.coastaleng.2016.05.008
复制
发表时间：
2016
影响因子：
4.4
通讯作者：
Stansby P
中科院分区：
文献类型：
--
作者：
Stansby P
具有再循环的岬角周围的潮汐流长期以来一直具有环境重要性，现在被考虑用于潮汐流涡轮机部署，因为水流在岬角尖端周围加速，与再循环区相互作用，产生高动能。将具有静水压力和 k-ε 湍流建模的 3D TELEMAC 模型与粗糙湍流条件下的表面速度矢量和流体速度时间序列的实验测量结果进行比较，其中床剪切应力是隐式的（边界层计算的一部分，不由摩擦系数定义）。尖端速度的大小以合理的精度预测，而再循环区域中的速度仅被近似预测。这些再循环区域周围的床摩擦系数可能比背景水平放大一个数量级，正如之前在岛屿尾流中发现的那样。边界层厚度通常小于水深，并且水平方向约为垂直方向六倍的两个混合长度模型可以提供稍微更好的再循环区速度预测，但需要估计边界层厚度。该实验具有扭曲（夸大的垂直）尺度，并且在模型中放松这一点，同时施加现场条件典型的无量纲粗糙度，得到的结果与实验条件非常相似，表明扭曲尺度物理模型对于这些条件是合理的，尽管这不应被假定为一般规则。广泛使用的深度平均模型的结果明显高估了尖端速度，特别是对于最小的振荡幅度，这可能与必然固定的摩擦系数和不存在二次流有关，从而允许再循环区域中人为地产生较高的速度，从而在流动反向后在尖端附近产生更高的速度。因此，这种相对简单的 3D 建模形式对于评估岬角周围潮汐流涡轮机的能量捕获似乎很有用。
Tidal flows around headlands with recirculations have long been of environmental importance and are now considered for tidal stream turbine deployment as flow accelerates around a headland tip, interacting with the recirculation zones, giving high kinetic energy. The 3D TELEMAC model with hydrostatic pressure andk-εturbulence modelling where bed shear stress is implicit (part of the boundary layer computation and not defined by a friction coefficient) is compared with experimental measurements of surface velocity vectors and fluid velocity time series for rough turbulent conditions. The magnitudes of tip velocity are predicted with reasonable accuracy while the velocities in the recirculation zones are only predicted approximately. The bed friction coefficient around these recirculation zones may be magnified by an order of magnitude over the background level as was previously found for island wakes. The boundary layer thickness is generally less than the water depth and a two mixing length model with the horizontal about six times the vertical gives slightly better recirculation zone velocity prediction but requires an estimate of boundary layer thickness. The experiment has a distorted (exaggerated vertical) scale and relaxing this in the model while imposing non-dimensional roughness typical of field conditions gave results very similar to those for experimental conditions indicating that the distorted scale physical modelling is justified for these conditions although this should not be assumed to be a general rule. Results from widely used depth-averaged modelling overestimated the tip velocities markedly, particularly for the smallest oscillation amplitude, presumably associated with the necessarily fixed friction coefficient and absence of secondary flow allowing artificially high velocities in the recirculation zones generating higher velocities near the tip after flow reversal. This form of relatively simple 3D modelling thus appears useful for assessing energy capture from tidal stream turbines around headlands.
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影响因子：
8.7
作者：
P. Stansby;T. Stallard
通讯作者：
P. Stansby;T. Stallard
影响因子：
3.6
作者：
BLACK, KP;GAY, SL
通讯作者：
GAY, SL
数值模型在水质研究中的应用。
DOI：
--
发表时间：
1993
期刊：
影响因子：
--
作者：
R. Falconer
通讯作者：
R. Falconer
对岛屿和地头周围的流动进行建模：使用 TELEMAC3D 应用两种混合长度模型
DOI：
--
发表时间：
2014
期刊：
影响因子：
--
作者：
Nicolas Chini;P. Stansby
通讯作者：
P. Stansby
影响因子：
3.7
作者：
P. Stansby
通讯作者：
P. Stansby