航空学报 > 2025, Vol. 46 Issue (2): 130618-130618   doi: 10.7527/S1000-6893.2024.30618

基于动力学模态分解的柔性膜翼增升机制

胡仕林, 陈柄宙, 康伟()   

  1. 西北工业大学 航天学院,西安 710072
  • 收稿日期:2024-04-28 修回日期:2024-05-07 接受日期:2024-05-13 出版日期:2024-05-24 发布日期:2024-05-22
  • 通讯作者: 康伟 E-mail:wkang@nwpu.edu.cn
  • 基金资助:
    国家自然科学基金(11972307);航空科学基金(JCKY2021204B141)

Lift improvement mechanism of membrane airfoil using dynamic mode decomposition

Shilin HU, Bingzhou CHEN, Wei KANG()   

  1. School of Astronautics,Northwestern Polytechnical University,Xi’an 710072,China
  • Received:2024-04-28 Revised:2024-05-07 Accepted:2024-05-13 Online:2024-05-24 Published:2024-05-22
  • Contact: Wei KANG E-mail:wkang@nwpu.edu.cn
  • Supported by:
    National Natural Science Foundation of China(11972307);Aeronautical Science Foundation of China(JCKY2021204B141)

摘要:

柔性薄膜翼型在低雷诺数范围内能够利用气动弹性效应自适应改善机翼表面气流分布,这种特性为智能飞行器气动与控制设计提供了新的思路。将柔性薄膜材料直接应用到翼型的设计中,对不同攻角状态与柔性长度下的柔性膜翼进行了流固耦合仿真,并采用动力学模态分解方法对膜翼流场进行模态分析。研究结果表明当流场一阶DMD模态与柔性结构一阶振动模态发生锁频时,柔性膜翼相对刚性翼型才会表现出增升效应。柔性膜翼在攻角为16°时增升21.74%,流场压力模态相位结果表明,这种增升效应来源于柔性结构振动产生的压力波对流场剪切层的能量反馈;柔性长度为0.65倍弦长的膜翼增升为14.22%,该构型下的膜翼表面能够产生具有较大压力相位梯度的右行压力波,使得表面气流最大限度地获得来自结构振动反馈的能量,其增升效应远大于其余柔性长度下的膜翼构型。研究为主动流动控制提供了重要的理论支撑。

关键词: 柔性膜翼, 动力学模态分解, 增升效应, 能量反馈, 流动控制

Abstract:

Membrane airfoils can adaptively improve the flow distribution on the surface of the airfoil using aeroelastic effects in the low Reynolds number flow, which offers a novel aerodynamic design concept for smart aerocraft. In this paper, the membrane material is directly applied to the design of airfoil. Numerical calculations for the fluid-structure interaction of the membrane airfoil with different angles of attack and length of membrane are conducted. Modal analysis of the flow field of the membrane airfoil is performed based on dynamic mode decomposition. The results indicate that compared to the rigid airfoil, the membrane airfoil shows lift enhancement when there exists a lock-in phenomenon between the flow and the membrane structure. The lift enhancement of the membrane airfoil at the angle of attack of 16° is 21.74%, which is attributed to the energy feedback of pressure propagation generated by membrane vibration on the shear layer of the flow. The lift enhancement of the membrane airfoil with the length of membrane of 0.65 times the chord length is 14.22%. The upper surface of the membrane airfoil in this configuration can generate a downstream pressure propagation with a large pressure phase gradient, which allows the flow on the surface can obtain the maximum energy from structural vibration feedback. The lift enhancement of the membrane airfoil in this configuration is much greater than that in other configurations. The proposed methods and research conclusions can provide important theoretical support for active flow control.

Key words: flexible membrane airfoil, dynamic mode decomposition, lift improvement, energy feedback, flow control

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