Centre for Offshore Foundation Systems, University of Western Australia, Crawley, Western Australia 6009, Australia.
Philos Trans A Math Phys Eng Sci. 2013 Jan 14;371(1985):20120176. doi: 10.1098/rsta.2012.0176. Print 2013 Feb 28.
Enhanced tidal streams close to coastal headlands appear to present ideal locations for the deployment of tidal energy devices. In this paper, the power potential of tidal streams near an idealized coastal headland with a sloping seabed is investigated using a near-field approximation to represent a tidal fence, i.e. a row of tidal devices, in a two-dimensional depth-averaged numerical model. Simulations indicate that the power extracted by the tidal fence is limited because the flow will bypass the fence, predominantly on the ocean side, as the thrust applied by the devices increases. For the dynamic conditions, fence placements and headland aspect ratios considered, the maximum power extracted at the fence is not related in any obvious way to the local undisturbed kinetic flux or the natural rate of energy dissipation due to bed friction (although both of these have been used in the past to predict the amount of power that may be extracted). The available power (equal to the extracted power net of vertical mixing losses in the immediate wake of devices) is optimized for devices with large area and small centre-to-centre spacing within the fence. The influence of energy extraction on the natural flow field is assessed relative to changes in the M2 component of elevation and velocity, and residual bed shear stress and tidal dispersion.
在近海岸岬角附近的增强潮流似乎是部署潮汐能装置的理想场所。本文利用近场近似表示潮汐围栏（即一排潮汐装置），通过二维深度平均数值模型研究了具有倾斜海底的理想近岸岬角附近潮流的功率潜力。模拟表明，由于装置施加的推力增加，流体会绕过围栏，主要是在海洋侧，因此潮汐围栏提取的功率受到限制。在所考虑的动力条件、围栏位置和岬角纵横比下，围栏处提取的最大功率与局部未扰动能通量或由于床面摩擦引起的自然能量耗散率（尽管过去曾使用这两者来预测可能提取的功率量）没有明显关系。可用功率（等于装置尾流中垂直混合损失的净提取功率）对于围栏内具有大面积和小中心到中心间距的装置进行了优化。相对于海平面和速度的 M2 分量的变化，评估了能量提取对自然流场的影响，以及剩余的床面剪切应力和潮汐弥散。
