Flow control to mitigate fatigue load through the use of flexible tidal turbine blades

该项目是一项利用柔性叶片提高潮汐涡轮机耐久性和生存能力的可行性研究。潮汐涡轮机所经历的高湍流导致了持续的负荷变化，限制了其疲劳耐力。为了控制叶片周围的流场，使涡轮叶片和轴承受恒定的应力，建议采用柔性叶片。在某一位置的起始流速沿叶跨变化的作用下，柔性叶片会改变局部迎角和叶型。叶片部分周围的新流场将使叶片部分上的负载变化最小化。如果不能完全避免，载荷变化的减小将增强叶片和轴的疲劳耐力。

The project is a feasibility study on the use of flexible blades to increase the durability and survivability of tidal turbines. The highly turbulent flow experienced by tidal turbines leads to continuous load variations limiting the fatigue endurance. It is proposed to use flexible blades in order to control the flow field around the blades and allow constant stresses on the turbine's blades and shaft. Under the effect of a variation of the onset flow velocity at a certain location along the blade span, the flexible blade will change the local angle of attack and the foil shape. The new flow field around the blade section will be as such to minimise the load change on the blade section. The reduced, if not completely avoided, load variations will enhance the fatigue endurance of the blade and the shaft.