水平轴风力机风轮振动与噪声耦合特性的关联性研究

Research on Coupling Relationship Between Wheel Vibration and Noise in a Horizontal Axis Wind Turbine

为了研究风力机风轮振动与噪声之间的关联性,以小型三叶片水平轴风力机为研究对象,在直流风洞中开展了风轮的模态实验和风轮振动与噪声耦合特性实验。结果表明:风轮的固有频率不能代替风轮的振动频率;在风力机风轮离心力载荷不变、气动载荷规律增大的情况下,风轮的圆盘效应、一阶、二阶振动频率与旋转基频所对应的最大声压级、叶尖涡脱落频率所对应的声压级基本保持不变;在风力机风轮气动载荷不变、离心力载荷规律增大的情况下,风轮的圆盘效应、一阶、二阶振动频率与旋转基频所对应的最大声压级、叶尖涡脱落频率所对应的声压级也规律增大,说明小型水平轴风力机风轮的振动与噪声呈正相关关系。

To find the correlation between wheel vibration and noise in a small three-blade horizontal-axis wind turbine,a modal experiment was conducted on the wheel,while an experiment was carried out on the coupling characteristics between the wheel vibration and noise in a direct-current wind tunnel.Results show that the natural frequency of the wheel can not be taken as the vibration frequency.In the case that the centrifugal force of wind turbine wheel is fixed and the aerodynamic load is increased regularly,all the disc effect,the first and second order vibration frequency,the maximum sound pressure level corresponding to the fundamental rotating frequency and the sound pressure level corresponding to the blade tip vortex shedding frequency would keep unchanged basically;whereas in the case that the aerodynamic load is fixed and the centrifugal force is increased regularly,all the disc effect,the first and second order vibration frequency,the maximum sound pressure level corresponding to the fundamental rotating frequency and the sound pressure level corresponding to the blade tip vortex shedding frequency would increase accordingly,indicating that the vibration frequency of a small horizontal-axis wind turbine is positively correlated to the sound pressure level.