水平轴潮流能水轮机叶片变桨角度研究

Study on influence of blade pitch angle on response of horizontal-axis tidal stream turbine

利用Flow-3D软件建立了单桩型水平轴潮流能发电机的三维数值模型。采用该模型对不同叶片变桨角度时的水动力过程进行了模拟计算,并根据计算结果从叶轮转速、叶轮动能、叶轮受力、水位和流速变化的角度进行了分析和讨论。数值模拟结果表明:当叶片变桨角度增大时,来流方向的叶轮受力和叶轮动能也都随之增大;变桨角度对于与来流垂直的y和z方向的叶轮受力影响较小;叶片变桨角度越大、水轮机下游附近流速降低的越快,流速就越小,而在水轮机下游较远处,叶片变桨角度越大,尾流场恢复得越快,其流速也越大。

A 3 D hydrodynamic model based on Flow-3 D is developed in this paper for single pile horizontal-axis tidal stream turbine and the influences of the blade pitch angle on the impeller rotation rate, the impeller kinetic energy, the fluid force, the water level and the flow velocity of the horizontal-axis tidal stream turbine are investigated by the model. Numerical analysis results showed that: when the blade pitch angle increases, the fluid force on the impeller in the direction of the incoming flow and the impeller kinetic energy increases;the pitch angle has little effect on the impeller force perpendicular to the incoming flow direction;the larger the blade pitch angle is, the flow velocity in the downstream of the turbine declines more quickly and the flow velocity is smaller;in far downstream of the turbine, the larger the blade pitch angle is, the faster the wake field recovers and the larger the flow velocity is.