Abstract A deep insight into wake of a tidal stream turbine can be essential to make tidal stream energy commercially viable. This study is to experimentally investigate downstream field of a horizontal axis tidal stream turbine supported by a mono pile. Two scenarios with and without a rotor are considered and compared with each other in this study. An advanced Acoustic Doppler Velocimeteris employed to measure the time-varying velocities up to eight rotor diameter downstream. Analyses of results show that the flow field within three rotor diameter downstream is strongly influenced by the supporting structures, which lead to asymmetric recovery trend for velocity, turbulence and Reynolds shear stress. Besides, flow characteristics within various lateral distances away from the rotating axis tend to recover in different rates. Both the rotor rotation and supporting structures result in highly anisotropic turbulence in the downstream field. Bed shear stress in the downstream field nearly doubles due to the rotating rotor, although its distribution pattern does not change.

中文翻译：

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单桩支撑水平轴潮汐流涡轮机下游场的试验研究

摘要 深入了解潮汐流涡轮机的尾流对于使潮汐能具有商业可行性至关重要。本研究旨在对单桩支撑的水平轴潮汐流涡轮机下游场进行实验研究。在这项研究中，考虑了有和没有转子的两种情况并相互比较。采用先进的声学多普勒测速仪来测量下游高达 8 个转子直径的时变速度。结果分析表明，下游三个转子直径内的流场受到支撑结构的强烈影响，导致速度、湍流和雷诺剪应力的不对称恢复趋势。此外，离旋转轴不同横向距离内的流动特性往往以不同的速率恢复。转子旋转和支撑结构都会在下游场中产生高度各向异性的湍流。由于转子旋转，下游场中的床剪切应力几乎翻了一番，尽管其分布模式没有改变。