浮体平台运动对浮式风电机组气动特性影响风洞试验

Influence of floating platform motion on aerodynamic characteristics of floating offshore wind turbines based on wind-tunnel tests

浮式风电机组作为一种大型海洋结构物和刚柔旋转体,其运行受到海风-波浪-洋流的组合扰动,服役环境恶劣,多体多场耦合动力学行为极其复杂,严重阻碍浮式风电技术的发展。针对该问题,本文进行了浮体平台运动下浮式风电机组模型的气动特性试验研究。通过六自由度平台控制机组模型不同的纵摇运动模式,进行定常风速下的风洞试验,获得了不同纵摇振幅下的气动性能变化规律。在静态倾斜测试中,功率系数随着纵摇角度的增大而减小,俯仰力矩系数和偏航力矩系数随着纵摇角度的增大而增大。动态测试的结果表明,纵摇状态下的力矩系数存在迟滞效应,且随着振幅的增大,迟滞效应明显增强,其中偏航力矩系数波动为逆时针方向,俯仰力矩波动为顺时针方向。本文揭示了平台纵摇运动对浮式风电机组气动特性的影响规律,对于厘清风-浪-流组合扰动下的气动-水动-伺服-弹性多体多场耦合机制具有重要意义。

As a large offshore structure with a rigid flexible rotating body,a floating wind turbine undergoes harsh service environment.Its multi-body and multi-field dynamic coupling mechanism is extremely complex,which has become a key bottleneck restricting the development of floating wind power technology.This paper studies the aerodynamic characteristics of a wind turbine model in a wind tunnel by varying the pitching motion of a six-degree-of-freedom platform on which the model is installed.The variation of aerodynamic performance with the pitching amplitude of the platform is obtained under the condition of steady incoming flows.In the static tilt experiment,the power coefficient decreases with the increase of the pitch angle,while the opposite is true for the pitch-and yaw-torque coefficients.A similar trend can also be found by increasing the yaw angle.This is because larger pitch or yaw angles make the model more inclined,which reduces the lift but increases the resistance considerably.In the dynamic experiment,the torque fluctuation manifest a"hysteresis loop"with respect to the pitching angle that is sensitive to the pitching amplitude.Specifically,the hysteresis loop of the fluctuating yaw-torque coefficient is counterclockwise while that of the fluctuating pitching-torque coefficient is clockwise.This paper reveals the influence law of specific platform motion on the aerodynamic performance of a wind turbine,which is of great significance for the aerodynamic and hydrodynamic control of wind turbines under the multi-physics coupling of wind,wave,and current.