蜻蜓懸停飛行之空氣動力學分析

蜻蜓的飛行能力相當卓越靈活，一直以來讓許多學者深感興趣，其中又以懸停的方式更為特別，若能清楚蜻蜓翅膀的運動軌跡與分析流場的變化，對於仿生研究與飛行機器設計都將有所幫助。本文為研究蜻蜓懸停的飛行方式，利用每秒80張的攝像機所拍攝晏蜓科Aeschna juncea的照片，其中蜻蜓在戶外以37Hz的拍翅頻率懸停在空中，建立一個三維模型，再用疊圖校對的量測方式，得到蜻蜓在不同時間下的運動參數，即蜻蜓翅膀的拍動角Φ、拍動平面偏離角θ、扭轉角ρ。接著藉由將三維模型轉換成二維，描述在二維的流場中的翅膀中心弦長的動態軌跡，以數值方法模擬出蜻蜓懸停在空中時，周圍的速度與壓力分佈，進而可以得到翅膀拍動時所產生之升力與阻力。並且模擬在單一翅膀運動時的速度與壓力分佈，探討在單一翅膀與前後兩翅相互影響的情況下，兩者之間的不同之處。

關鍵字

蜻蜓；懸停；翅膀運動參數；計算流體力學

並列摘要

Dragonflies’ flying ability is extraordinary, which attracts many scholars to dig into. Among the way of dragonfly flight, hovering is the most special topic. If we can analyze the trajectory of a dragonfly’s wings and its flow field, it will be helpful for bionic research and designing flying machine. To study the hovering dragonfly fight, we make use of the photos of the dragonfly (Aeschna juncea), which are taken by high-speed camera at 80 frames s-1 with the dragonfly wingbeat frequency at 37Hz. We build a three-dimensional (3D) model of the wings, and then use the model to measure the kinematic parameters varying from the photos. Next, by transforming three-dimensional model (3D) from two-dimensional model (2D), we can describe the trajectory of mid-span chord in 2D flow field. Then, by numerical method, we simulate the velocity and pressure distribution when the dragonfly is hovering, which help us to get the lift and the drag generated by wingbeat. Also, we simulate the velocity and pressure distribution at single-wing movement to study the difference movement of single wing from the fore- and hindwings.

並列關鍵字

dragonfly ； hovering ； wing kinematics ； computational fluid dynamics ； Aeschna juncea

參考文獻

[1] M. Jensen. Biology and physics of locust flight. iii. The aerodynamics of locust flight. Proc. R. Soc. B. 239 239:511-52. (1956)

[2] W. Nachtigall. Die kinematik der schlagfugelbewegungen von dipteren. Methoddische und analyticshe grundlagen zur biophysik des insektenflugs. Z. Vergl. Physilo. 52:155-211. (1966)

[4] A. Magnan. La Locomotion chez les Animaux. I. Le Vol des Insects. Paris:Hermann et Cie. (1934)

[7] T. Weis-Fogh. Energetics of hovering flight in hummingbirds and Drosophila. J. exp. Biol. 56, 79-104. (1972)

[9] R.A. Norberg. Hovering flight of the dragonfly Aeschna juncea L., kinematics and aerodynamics. In Swimming and Flying in Nature, vol. 2(ed. T. Y. Wu, C. J. Brokaw and C. Brennen),763-781. (1975)

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蜻蜓懸停飛行之空氣動力學分析

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