中文摘要：

为了探究风向变化对风力机尾流的影响，选取NREL5MW风力机建立模型，采用Fluent软件在额定工况下对单台风力机及风向变化时的2台风力机进行数值模拟，并对比其输出功率及尾流的流动情况．结果表明：当风向变化角为0°，即串列排布时，上游风力机对下游风力机的影响很大；随着风向变化角由5°增大到10°，上游风力机对下游风力机的影响逐渐减小，下游风力机的功率减小率由7．53％减小到4．24％，输出功率明显增加，可见风向变化对风力机尾流有影响．

英文摘要：

To study the wake effect of wind turbines at varying wind directions, the NREL 5 MW wind turbine model was esteblished and then a single wind turbine and two wind turbines were respectively simula- ted at varying wind directions under rated wind condition using Fluent software, so as to compare their power output and wake flow. Results show that when the wind direction is at 0°, namely tandem arrangement, the upstream wind turbine would have a big effect on the downstream one; when the angle of wind direction varies from 5°to 10°, the influence of upstream wind turbine on downstream wind turbine would be reduced, and the power loss of downstream wind turbine would be lowered from 7. 53% to 4.24%. with obvious increase of power output simultaneously, indicating that the wake flow of a wind turbine may be affected by the change of wind directions.