基于改进后的动态失速模型,研究非线性气动作用下的二维翼型颤振特性。从初始附着流出发,对比研究临界速度以下、以上时,系统的时域位移、气动力变化,发现气动非线性主要影响临界流速以上的极限环振荡阶段;从振幅增速的角度,发现对系统稳定性强弱的判断受时间尺度定义的影响;从改变翼型平均攻角的角度,气动非线性在振动收敛时影响较小,而在颤振阶段影响较大,表现为改变系统的动态失速特性;对于高攻角下的初始分离流,不同计算结果展现出强烈的差异性、非线性,系统的颤振信号具有显著的单自由度特征。
Abstract
Aeroelastic characteristic of 2D airfoil under nonlinear aerodynamics is studied based on a modified dynamic stall model. Begin with initial attached flow, the displacement and force signal are compared below and beyond the critical velocity. It’s found that the nonlinear aerodynamics mainly appears beyond the critical velocity. The comparison of stability is found affected by the definition of time whether dimensional or nondimensional. Changing mean angle of attack shows small influence when velocity under the critical, but considerable beyond the critical. One obvious variation is found on dynamic stall feature. For a separated at high angle of attack, different calculations reveal strong diversity and nonlinearity, and 1D tendency is found in all separated flutter cases.
关键词
风力机 /
翼型 /
气动载荷 /
气动失速 /
颤振
Key words
wind turbines /
airfoils /
aerodynamic loads /
aerodynamic stalling /
flutter
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基金
国家重点研发计划（2020YFB1506601）; 上海市科技创新行动计划资助项目（20dz1205300）
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