中文摘要：

塔架与叶片间的非定常相互作用是影响风力机气动性能、机组疲劳载荷和寿命的主要因素之一。本文采用NUMECA商用软件FINETM／Turbo，对上风向型风力机DF90的三维风轮叶片和塔架模型进行非定常数值模拟，详细分析了塔影效应对风力机气动性能的影响。结果显示：塔架的阻碍作用引起叶片载荷的剧烈变化（单叶片载荷波动20％-40％，风轮载荷波动6％-12％），与文献显示的风场试验结果一致。在此基础上从叶片表面压力、载荷和流场细节等角度分析了塔影效应的影响，揭示了三维非定常变化的发生机理，为风力机的设计运行提供参考。

英文摘要：

The rotor-tower unsteady interaction is one of the key reasons that would seriously affect the wind turbine performance, fatigue load and the lifetime. An upwind wind turbine DF90 with blades and tower is used as the simulation model to analysis the tower shadow effect on wind turbine performance, by using the commercial CFD software Fine/TurboTM. The results show that the block of tower will cause dramatic changes of blade load （the load fluctuations of an isolate blade load is 20%-40%, and 6%-12% for rotor）, which is in accordance with the references. Then the shadow effect on pressure distributions of blade surface, loads and flow fields, etc. are discussed in detail, for the mechanism of 3D unsteady response, as well as practical suggestions for wind turbine design and operation.