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Purpose <p>Due to their excellent mechanical properties and designability, 2.5D composites are increasingly used in the rotor structure of an engine. However, the research on the flutter problem of 2.5D composite blades is extremely limited, especially in the case of complex aerodynamic excitation. This paper focuses on the Flutter analysis of 2.5D C/SiC composite blades considering the wake excitation, revealing vibration response in the first-order primary resonance region of the blade before and after the flutter is studied in depth considering wake excitation, and the influence of parameters on the flutter boundary and the amplitude-frequency response in the first-order primary resonance region are analyzed in detail.</p> Methodology <p>In this study, the elastic constants and density of the 2.5D C/SiC composite are obtained by volume average, the aerodynamic force on the blade consists of aeroelastic coupling term and wake excitation to characterize the actual complex coupled and uncoupled aerodynamic forces on the blade, the blade is treated as a flat and straight plate with a fixed connection to the rotor at its root, and its mechanical model of composite blade is established by Rayleigh–Ritz method and Hamiltonian's principle.</p> Results and Conclusion <p>Various nonlinear phenomena, including bistable, amplitude jumps, caused by wake excitation, are found. The harmonic component of self-excited does not appear in the first-order primary resonance before flutter, but it appears after flutter. Most prominently, wake excitation has a suppressive effect on the self-excited response after the flutter, and the rotational speed region with self-excited vibration fades from the region near the resonance peak to the non-resonance region with the increase of the amplitude of excitation. Additionally, the increase of aspect ratio and weft arrangement density significantly reduces the flutter boundary of the blade; the aspect ratio also more significantly affects the vibration response in the first-order primary resonance region, and the blade with a high aspect ratio is more prone to chaotic motion. The study in this paper is of great significance in revealing the effects of wake excitation on the flutter characteristics of the blade and developing the anti-flutter design of 2.5D C/SiC composite blades.</p>

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Flutter Analysis of a 2.5D C/SiC Composite Blade Considering Wake Excitation

  • 期刊论文

  • 发表日期：

    2025年6月14日

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  • Qian Xu,
  • Lei Hou,
  • Shuangxing Ren,
  • Lixian Hou,
  • Zhonggang Li,
  • Nasser A. Saeed

摘要

Purpose

Due to their excellent mechanical properties and designability, 2.5D composites are increasingly used in the rotor structure of an engine. However, the research on the flutter problem of 2.5D composite blades is extremely limited, especially in the case of complex aerodynamic excitation. This paper focuses on the Flutter analysis of 2.5D C/SiC composite blades considering the wake excitation, revealing vibration response in the first-order primary resonance region of the blade before and after the flutter is studied in depth considering wake excitation, and the influence of parameters on the flutter boundary and the amplitude-frequency response in the first-order primary resonance region are analyzed in detail.

Methodology

In this study, the elastic constants and density of the 2.5D C/SiC composite are obtained by volume average, the aerodynamic force on the blade consists of aeroelastic coupling term and wake excitation to characterize the actual complex coupled and uncoupled aerodynamic forces on the blade, the blade is treated as a flat and straight plate with a fixed connection to the rotor at its root, and its mechanical model of composite blade is established by Rayleigh–Ritz method and Hamiltonian's principle.

Results and Conclusion

Various nonlinear phenomena, including bistable, amplitude jumps, caused by wake excitation, are found. The harmonic component of self-excited does not appear in the first-order primary resonance before flutter, but it appears after flutter. Most prominently, wake excitation has a suppressive effect on the self-excited response after the flutter, and the rotational speed region with self-excited vibration fades from the region near the resonance peak to the non-resonance region with the increase of the amplitude of excitation. Additionally, the increase of aspect ratio and weft arrangement density significantly reduces the flutter boundary of the blade; the aspect ratio also more significantly affects the vibration response in the first-order primary resonance region, and the blade with a high aspect ratio is more prone to chaotic motion. The study in this paper is of great significance in revealing the effects of wake excitation on the flutter characteristics of the blade and developing the anti-flutter design of 2.5D C/SiC composite blades.