Transonic flutter characteristics of an airfoil with morphing devices
Transonic flutter characteristics of an airfoil with morphing devices
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DOI：
10.1177/0954410020953046
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发表时间：
2020-08
期刊：
影响因子：
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通讯作者：
Shun He;Shijun Guo;Wenhao Li
中科院分区：
文献类型：
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作者：
Shun He;Shijun Guo;Wenhao Li
本文对一种具有变形前后缘的翼型的跨音速颤振特性进行了研究。采用计算流体动力学（CFD）方法计算跨音速流中的非定常气动力。数值模拟中采用了基于外生输入自回归模型（ARX）的气动降阶模型（ROM）。颤振解由特定马赫数下的特征值分析确定。将该方法应用于变形翼型，并与相关文献进行了比较，验证了该方法的有效性。研究表明，采用变形后缘后，激波在较低的马赫数下形成并向后缘移动，气动力稳定提前发生。同时，最小颤振速度增加，跨音速下降发生在较低的马赫数。前缘变形对激波和跨音速颤振的影响可以忽略不计。从翼型表面激波位置、非定常气动力和颤振解的关系出发，探讨了变形技术改善翼型跨音速颤振特性的机理。
An investigation into transonic flutter characteristic of an airfoil conceived with the morphing leading and trailing edges has been carried out. Computational fluid dynamics (CFD) is used to calculate the unsteady aerodynamic force in transonic flow. An aerodynamic reduced order model (ROM) based on autoregressive model with exogenous input (ARX) is used in the numerical simulation. The flutter solution is determined by eigenvalue analysis at specific Mach number. The approach is validated by comparing the transonic flutter characteristics of the Isogai wing with relevant literatures before applied to a morphing airfoil. The study reveals that by employing the morphing trailing edge, the shock wave forms and shifts to the trailing edge at a lower Mach number, and aerodynamic force stabilization happens earlier. Meanwhile, the minimum flutter speed increases and transonic dip occurs at a lower Mach number. It is also noted that leading edge morphing has negligible effect on the appearance of the shock wave and transonic flutter. The mechanism of improving the transonic flutter characteristics by morphing technology is discussed by correlating shock wave location on airfoil surface, unsteady aerodynamics with flutter solution.