purpose

This paper aims to investigate the post-flutter nonlinearities due to the wing high aspect ratio. Flutter is an aerodynamic auto-excited phenomenon which occurs due to the coupling of two or more different vibration modes. This coupling results from the interaction between aerodynamic, elastic, and inertial forces. The present investigation scope is the comparison between experimental aeroelastic analysis of high-aspect-ratio wings using subsonic wind tunnels with computational experiments for three different center of gravity conditions.

Methods

The computational nonlinear aeroelastic analysis is performed using a formulation based on the variation of the energy functional and considering Peters’ unsteady aerodynamic model. The post-flutter analysis consists in the comparison between the attractor reconstructed using the Takens’ theory with the result of the 0–1 test for chaos for both computational and wind tunnel experiments.

Results

First, the 0–1 test is performed for both computational nonlinear analysis and wind tunnel experiment and they are in good agreement for each condition. After that, the procedure to obtain the reconstructed attractor is followed for both cases and they are again in good agreement. The difference between computational experiment reconstructed attractors and wind tunnel experiment reconstructed attractors is mainly because of wind turbulence in wind tunnel section.

Conclusion

This research shows that all three experimented conditions presented periodic dynamic behavior. The 0–1 test predicted well the dynamic behavior; therefore, it is recommended to apply this test for all nonlinear experiments so that a first qualitative evaluation is possible. All Lyapunov exponents calculated are negative, confirming the periodicity of the three center of gravity conditions for both computational and wind tunnel experiments.

中文翻译：

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航空弹性系统的0-1混沌测试与吸引子重构的比较

目的

本文旨在研究机翼高纵横比导致的后颤振非线性。颤振是一种空气动力自激现象，由于两种或多种不同振动模式的耦合而发生。这种耦合是由空气动力，弹性力和惯性力之间的相互作用引起的。本研究的范围是使用亚音速风洞进行高纵横比机翼的空气动力学弹性分析与三种不同重心条件的计算实验之间的比较。

方法

使用基于能量函数变化并考虑Peters非定常空气动力学模型的公式进行计算非线性空气弹性分析。颤振后分析包括将使用Takens理论重建的吸引子与计算和风洞实验的0-1混沌测试结果进行比较。

结果

首先，对计算非线性分析和风洞实验都进行了0-1试验，并且在每种情况下它们都具有很好的一致性。此后，两种情况都遵循获取重建吸引子的过程，并且它们再次非常吻合。计算实验重建吸引子与风洞实验重建吸引子的差异主要是由于风洞截面中的风湍流。

结论

这项研究表明，所有三个实验条件都表现出周期性的动态行为。0-1测试很好地预测了动态行为。因此，建议将此测试应用于所有非线性实验，以便可以进行第一定性评估。计算出的所有Lyapunov指数均为负，确认了计算和风洞实验的三个重心条件的周期性。