基于改进致动盘和拓展k-ε湍流模型的风力机尾流数值研究

Study of Wind Turbine Wake Modeling Based on a Modified Actuator Disk Model and Extended k-ε Turbulence Model

提出了适用于风力发电机组尾流的数值计算方法:将风轮简化成致动盘,附加动量源项;引入改进湍流方程源项,改善标准k-ε湍流模型造成的尾流恢复过快的问题;应用分布函数改进动量源项和湍流源项系数C4ε沿风轮径向的分布规律。以Nibe-B和Dawin 180/23这2种风力发电机尾流为例,使用不同的尾流模型计算出风力机在多种入流风速下的尾流场。结果表明,与其他尾流模型相比,改进后的模型相对于实验结果具有更高的预测精度,能够更好地模拟风力发电机尾流。

This paper presented an improved computational fluid dynamics（CFD） model for simulating a horizontal-axis wind turbine wake. The model used the actuator disk model to simplify the wind turbine effect on the aerodynamic field by adding an extra momentum source and an improved term to correct the underestimation issue of the wind speed deficit when applying the STD k-ε model. In addition, the model also introduced a radial distribution function to assess the non-uniform load on the actuator disk and a coefficient C4ε of the turbulent source. To validate the model, the wind turbines of Nibe ‘B＇ and Dawin 180/23 were checked by different wake models with multiple entrance velocities. Results show that the improved wake model has better prediction accuracy with experimental data and can be used for wind turbine wake calculation.