真实地形对实尺寸潮流能水轮机影响研究

Study on the Influence of Real Terrain on Utility-scale Tidal Turbine

在真实的流场下,海底地形会对潮流能水轮机的性能带来不可忽略的影响。以目前安装于舟山国家潮流能示范场的450kW水平轴水轮机为研究目标,以现场真实地形为基础,通过实测流场和水槽实验验证了计算流体动力学方法建立的水轮机模型。在此基础上,对位于水底斜坡上的装置性能及尾流发展进行了考察。研究结果显示,在潮流上坡时,性能提升可达到20%;而在潮流下坡时,水轮机性能出现明显退化,效率衰减约10%,同时轴向负载增加超过5%。此外,水底地形将会显著影响水轮机的尾流发展,尾流会自发向水深更深的区域偏移;随着潮流流速的增加,尾流波及区域也会明显延长。

In the real flow field,submarine terrain has a considerable impact on a tidal turbine.In this paper,the research object is a 450kW horizontal-axis tidal turbine,which is currently deployed at the Zhoushan national tidal energy test site.Based on the real terrain,a turbine model established by the computational fluid dynamics(CFD)method is verified by measured flow field and flume experiment.On this basis,the turbine performance and wake development on the underwater hillside are studied.The research results show that the turbine efficiency can be increased by 20%when the tidal current is uphill.The performance degrades noticeably when the tidal current is downhill,accompanied by a 10%drop in efficiency and a 5%increase in axial load.Besides,the terrain has a greater influence on wake development.The wake naturally develops towards deeper water areas,and the impacted region increases considerably as the tidal velocity rises.