特徵值的分析可以判定一個系統的穩定性,而對於氣體彈性力學特徵值的分析而言也是很重要的一部分。本文將用富羅格理論對葉片-尾流耦合系統做特徵值分析,並透過此法對四個葉片的旋翼在前飛時做拍撲運動的各組模態( modes)做辨識及探討。本文發現考慮尾流動力影響與不考慮誘導流系統之旋翼葉片特徵值做比較時,即使在很高的前飛率時,誘導流對葉片動力的影響仍然很大。
An eigenvalue study can provide stability information for a system, and it is also and important part of aeroelastic analysis. In this work, the blade-wake coupled system eigen- analysis is studied by the Floquet Theory, and the flapping modes for a four-bladed rotor are investigated and identified through their eigenvalues. The eigenvalues of the Floquet matrix can determine system characteristics. The effect of wake dynamics on rotor blade eigenvalues can be seen by comparison with no inflow case. The results show that the inflow has a profound effect on blade dynamics, even at high advance ratios. An eigenvalue study can provide stability information for a system, and it is also and important part of aeroelastic analysis. In this work, the blade-wake coupled system eigen- analysis is studied by the Floquet Theory, and the flapping modes for a four-bladed rotor are investigated and identified through their eigenvalues. The eigenvalues of the Floquet matrix can determine system characteristics. The effect of wake dynamics on rotor blade eigenvalues can be seen by comparison with no inflow case. The results show that the inflow has a profound effect on blade dynamics, even at high advance ratios.
