摘要
更好地了解山地上风力机尾流和功率特性有助于山地风电场的布局设计。本研究采用高精度的大涡模拟(large-eddy simulation, LES)研究了上游山脉对下游山脉顶部风力机的尾流和功率性能的影响。在基于伪谱法的LES框架中,本文分别使用了滤波致动盘模型和浸入边界法模拟风力机和山脉对气流的作用。研究表明,LES结果与实验测量的速度和湍动能吻合很好,对湍动能的预测优于雷诺平均Navier-Stokes(Reynolds average Navier-Stokes, RANS)方法。在山脉风力机尾流的模拟中,研究发现风力机尾迹中心轨迹在山顶下风处向下偏转。与孤立山地相比,双峰型山地的尾流恢复速度更快,其恢复速率随着山脉间距的增加先增加后减少。对于有山脉情况,尽管由于气流的加速效应,高斯分布与尾流速度亏损分布在尾流下边缘存在差异,但高斯曲线仍然适用于近似风力机尾流的速度亏损。此外,因为上游山脉尾迹会扩散且到达下游山脉迎风面时会被抬升,所以当山脉间距达到一定距离时,风轮会完全浸没在上游山脉尾迹中,导致风力机功率性能受到上游山脉的不利影响,随着山脉间距的增加先下降后上升。本研究加深了对山地风力机尾流特性和功率性能的认识,对山区风电场的布局设计具有指导意义。
A better understanding of the wake and power characteristics of wind turbines over hills could facilitate the layout design of wind farms in hilly terrain.High-fidelity large-eddy simulation(LES)is employed to investigate the effects of an upwind hill on the wakes and power performance of the turbine sited on the downwind-hill crest.In our pseudo-spectral LES framework,the wind turbine is parameterized by actuator disk model and numerical boundary condition of the terrain is modelled by immersed boundary method.It is found that our LES is in excellent agreement with the measured velocity and turbulence kinetic energy,outperforming the RANS method in terms of predictions of turbulence kinetic energy.The wake-center trajectory downwind of the hilltop is found to deflect downwards.Compared with the single-hill case,the wake recovery becomes faster in the double-hill cases,and its recovery rate first increases and then decreases as the distance between hills increases.It is seen that the Gaussian distribution is appropriate to describe the velocity deficit in turbine wakes in the hill cases,although a mismatch between them is found in the lower wakes due to the flow acceleration.Besides,the turbine rotor is found to be totally immersed in the upwind-hill wakes when the distance between hills reaches a certain distance.Furthermore,the power performance of the wind turbine is adversely affected by the upwind hill,which first drops and then rises as the distance between hills increases.The research improves our understanding of the wake characteristics as well as power performance of wind turbines over hills and is of guiding significance for the layout design of wind farms in hilly terrain.
作者
张子瑜
黄鹏
曹曙阳
ZHANG Ziyu;HUANG Peng;CAO Shuyang(State Key Laboratory of Disaster Reduction in Civil Engineering,Tongji University,Shanghai 200092,China;Department of Civil and Environmental Engineering,University of Western Ontario,London N6A 5B9,Canada)
出处
《空气动力学学报》
CSCD
北大核心
2024年第5期97-109,共13页
Acta Aerodynamica Sinica
关键词
风能
大涡模拟
大气边界层
山脉
风力机尾流
功率性能
wind energy
large-eddy simulation
atmospheric boundary layer
hilly terrain
turbine wakes
power performance
