半潜式海上风力机涡激运动试验研究

采用水槽模型试验的方法测试半潜式海上风力机在不同流向角下的涡激运动特征,并从响应幅值、运动频率等角度对其涡激运动的关键特征进行分析研究。结果表明:在不同来流方向情况下,半潜式海上风力机均未发生明显的频率锁定现象,但可根据质心运动轨迹等现象界定传统意义上锁定区域范围;根据运动频率特征可把半潜式海上风力机基础结构的涡激运动过程大体分为3个阶段,且各流向角情况下风力机运动频率规律类似,而响应幅值出现明显区别:流向角为0°或15°时,结构的响应幅值随约化速度的增大近似呈线性增大的趋势;流向角为30°或45°时,结构在锁定区域内的运动响应则出现明显的共振现象。艏摇运动固有频率对风力机涡激运动基本无影响,艏摇运动频率与横荡运动基本保持一致。15°流向角的多个约化速度下观察到“自激”现象,并对此现象做出初步解释。

EXPERIMENTAL STUDY ON VIM OF SEMI-SUBMERSIBLE OFFSHORE WIND TURBINE

The vortex induced motion of semi-submersible offshore wind turbine under different current directions was investigated.Some characteristics were analyzed,such as amplitudes,frequency and so on.The results show that there is no obvious frequency“lockin”phenomenon under different current directions,but“lock-in”range in traditional significance can be defined based on centroid trajectory.The progress of vortex induced motion can be mainly divided into three stages based on frequency.Moreover,the vibration frequency shows a similar trend under different current directions,but its amplitudes change apparently.The amplitude increases linearly with the reduced velocity when the incidence angle is 0°or 15°.Obvious resonance is observed in lock-in area for 30°and 45°.The natural frequency of yawing has little effect on the vortex induced motion of wind turbine.And the natural yawing frequency is nearly same as that of swaying.“Self-excited”phenomenon is observed at various reduced velocities when the incidence angle is 15°,and a preliminary explanation is given here.