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风轮运行过程中存在来流激励的振动响应,为了使计算结果更接近真实情况,应该在风轮的数值模拟研究中考虑振动情况。本文在水平轴风力机风轮表面动压模拟计算中施加了一阶对称挥舞振动。风轮模态参数通过单点激励多点响应的试验模态分析方法获得,根据动网格技术中网格变形的要求拟合一阶挥舞振动振型特征向量,定义的模态振型控制方程通过用户自定义函数施加于风轮模型,风轮的旋转通过滑移网格技术实现。大涡模拟计算结果表明:旌加模态振型后,风轮表面动压呈周期性变化,其脉动频率与叶片旋转频率不一致;随着尖速比和来流风速的增加,动压脉动频率均增加,且增加幅值逐渐放大,其中来流风速对动压脉动频率的影响更显著。
In order to make the calculation result closer to the real situation, the vibration of the rotor should be considered in the numerical simulation of rotor. In this paper, a first-order symmetrical wave vibration is applied in the simulation of hydrodynamic pressure on the surface of a horizontal-axis wind turbine rotor. The modal parameters of the wind turbine are obtained by the experimental modal analysis method of single-point excitation multi-point response. According to the requirements of grid deformation in moving grid technology, the first-order wave vibration mode characteristic vector is fitted, and the modal governing equation Through the user-defined function applied to the rotor model, the rotation of the rotor is achieved by the slip-grid technique. The results of large eddy simulation show that the dynamic pressure on the surface of the wind turbine periodically changes after the Jingjung mode shape, and the pulsation frequency is inconsistent with the blade rotation frequency. With the increase of the tip speed ratio and the flow velocity of the incoming flow, the dynamic pressure pulsation frequency All increased, and the amplifying amplitude increased gradually. The influence of the flow velocity on the frequency of arterial pressure pulsation was more significant.