IDDES方法模拟风切变下大型水平轴风力机流场特性

The Flow Field Characteristics of Large Horizontal Axis Wind Turbine in Shear Inflow Based on IDDES Method

为研究风切变条件下大型水平轴风力机流场特性,以NH 1500 kW大型水平轴风力机为研究对象,运用计算流体力学中模拟流场精度较高的IDDES(改进延迟分离涡)方法,分析流场内瞬时速度分量、脉动速度和风力机输出功率。结果表明:风轮平面周围流场速度波动大,轴向速度在风轮旋转边界以外的区域会增大,在旋转边界以内的区域会亏损;脉动风速频谱特性在低频区与风轮转频的整数倍相关,风力机功率呈余弦形式输出并满足湍流谱特性。

In order to study the flow field characteristics of large horizontal axis wind turbine under wind shear,the NH 1500 kW large horizontal axis wind turbine was taken as the research object.The flow field characteristics such as instantaneous velocity component,pulsation velocity and wind turbine output power were analyzed by IDDES(improved delayed detached eddy simulation)method with high simulated flow field accuracy in CFD.The results show that the flow field velocity around the wind wheel plane fluc-tuates greatly,and the axial velocity increases outside the rotating boundary of the wind wheel,while de-creases within the rotation boundary.The spectral characteristics of the pulsation velocity are related to the integer times of the rotation frequency of the wind wheel in the low frequency region.The simulated wind turbine power in cosine form satisfies the turbulent spectral characteristics.