A Scaling Parameter for the Thrust Generation of Flapping Flexible Wings
A Scaling Parameter for the Thrust Generation of Flapping Flexible Wings
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扑动柔性翼推力产生的尺度参数
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
W. Shyy
中科院分区：
文献类型：
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作者：
Chang;H. Aono;C. Cesnik;W. Shyy
利用计算流体动力学和结构动力学求解器的集成框架研究了柔性扑翼的推力产生和缩放参数。为了研究密度比和有效刚度对推力产生的影响，建立了在= 1.5×10 3的静止空气中扑动的各向同性薄平板齐默尔曼机翼的代理模型.时间平均推力、弯曲角和扭转表现出定性相似的行为，并且随着密度比和有效刚度之间的比率增大而增大。在机翼中的柔性引起的扭转促进了推力的产生。为了进一步研究柔性引起的推力增强，考虑了在= 9.0× 103的水中前飞的垂向柔性翼型。翼型厚度越大，时间平均推力越大，但是当运动频率变高时，最薄翼型的性能下降。最后，基于适当规范化的控制方程，提出了统一的尺度参数，并给出了时均推力和流固耦合度的先验量级估计。结果表明，这些缩放参数，给定的组合的机翼的几何形状，结构特性，和运动的振幅和频率，可以适用于这两种情况下与不同的运动类型，雷诺数，和流体介质。
Thrust generation and scaling parameters for flapping flexible wings are investigated using an integrated framework of computational fluid dynamics and structural dynamics solvers. To explore the influences of the density ratio and the effective stiffness on the thrust generation, surrogate models have been generated for a flapping thin isotropic flat Zimmerman wing in still air at = 1.5×10 3 . Time averaged thrust, bending angle, and twist show qualitatively similar behavior and increased with higher ratio between the density ratio and effective stiffness. Flexibility-induced twisting in the wing promotes the thrust generation. To further investigate the flexibility-induced thrust enhancement, plunging chordwise flexible airfoils in forward flight at = 9.0×10 3 in water are considered. Time averaged thrust increases with larger airfoil thickness, however the thinnest airfoil responded with degradation in performance when motion frequency becomes high. Finally, unified scaling parameters are proposed based on properly normalized governing equations and give a priori order of magnitude estimation of the time averaged thrust and the degree of fluid-structure coupling. The results show that these scaling parameters, given as combinations of the wing geometry, structural properties, and the motion amplitude and frequency, can be applied for both cases with different motion type, Reynolds number, and the fluid medium.
DOI：
10.1007/978-3-540-89393-6
发表时间：
2010
期刊：
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影响因子：
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