动态潮汐能大坝水头数值计算

动态潮汐能是一种新型的潮汐能开发方式,由荷兰海岸工程师Hulsbergen和Steijn提出,具体为建立一个长度为几十千米以上且垂直于海岸线的T型坝,使沿岸的潮汐波变形,从而在坝的两侧产生水头差,可用于潮汐能发电。不同的大坝尺寸会产生不同大小的水头,理论公式和数值模型均被用于计算该水头大小。本研究利用Kolkman公式和平直海岸二维潮流模型,分别计算了作用在大坝上的动态水头并进行无量纲处理,对比发现两种方法获得的结果较为接近。其中采用Kolkman公式所获结果略小,说明在开阔海域中海底阻力对动态潮汐能起次要作用,Kolkman公式忽略阻力项的算法是可行的,理论公式也同样能够反映潮汐和大坝的相互作用,通过Kolkman公式和数值模拟结果的互相验证,可以提高水位差的计算准确度。

Numerical calculation of water head of dynamic tidal power dams

Dynamic tidal power (DTP) is a new way of tidal energy development, a technique that was first proposed by Dutch coastal engineers. The major structure is a T-shape dam of dozens of kilometers long, with its main axis perpendicular to the shoreline, to produce deformation of tidal waves and a difference in water head on the two sides of dam. The head difference for power generation depends on the size of the dam and is often calculated using a theoretical formula or a numerical model. This paper focuses on predicting the dynamic water head difference across the dam using the Kolkman formula and a 2D tidal flow numerical model. Model results show that the difference between the two predictions are relatively small and the values of Kolkman formula are smaller. This means that the seabed resistance is a minor factor of the DTP for open sea areas and for such areas ignore this term is reasonable. A good theoretical formula can reflect the interacting effect of tides and dam, and the accuracy of water level difference calculation will be improved through mutual verification of the Kolkman formula and numerical method.