本研究仿照岩鴿(Columba livia)外型、尺寸及特定飛行條件(16 m/s，拍撲頻率6 Hz)下之動作模式，設計並製作單自由度拍撲試驗機構，搭配兩種不同勁度的人造飛羽(artificial remiges)，與一套採集至岩鴿成鳥的飛羽，組合出雙側羽翼，以風洞試驗量測由不同剛性羽毛所組成的羽翼，產生之垂直力與水平力動態變化。
翼面的剛性分佈特性，對拍撲翼的流固耦合現象與氣動力生成效益具有重大的影響，以大部份翼面積由飛羽組成的鳥類羽翼而言，飛羽的剛性分佈狀態是決定此性質的關鍵因素。此外飛羽疊層的順序使之具有上下拍不對稱的形變模式，並帶來相應的氣動力效應。利用3D列印技術，以PLA與PETG材料製作軟、硬性質的人造飛羽，與生物採樣飛羽(REAL, Remiges Extracted from Avian Limbs)組成翅膀模型，以3-6 Hz拍撲頻率，在靜流場(0 m/s)與動流場(16 m/s)中運行，量測過程中機身所受之水平力、垂直力與肩關節角位移、平均電功率等數據，據此標定拍撲周期與力的對應關係，並計算出垂直合力、垂直慣性力、升力與推力隨周期變化的走勢，以及平均氣動力效益。比較具有不同剛性羽翼之氣動力效應，將有助於了解鳥類拍撲飛行的部份機制，並應用於未來的仿生飛行器設計。
三組羽翼在靜態流場中，無法產生有效的淨升力，而在動流場中淨升力隨拍撲頻頻變化，PETG具有最佳的淨升力效益。PETG翼在所有測試條件中其推進效益最佳，但REAL在設計飛行條件(16 m/s、6 Hz)最有最低功耗。

SUMMARY
In this study, we designed and fabricated a 1DOF (degrees of freedom) mechanism composed of feathered wings that mimic pigeons' (Columba livia) shape, size, and motion. There are three wing models, each built with different types of remiges. One of them was composed of REAL (Remiges Extracted from Avian Limbs) feathers extracted from a newly dead race pigeon. The other two models both use artificial remiges made by 3D printing but different materials that are stiff PLA and soft PETG.
In order to understand the aerodynamic performances affected by the characteristics of remiges, we measured real-time vertical/horizontal force, flapping angle, and average power input while flapping in a wind tunnel. These tests were conducted at 0m/s and 16m/s flow rates. Flapping frequencies were between 3.0-6.0 Hz. The selected remiges were examed by 3-point (non-destructive) bending tests, to measure the stiffness distribution of samples. The average bending stiffness of remiges is PLA>REAL>PETG.
Although feathers splitting while upstroke was observed in the static flow field, there was no significant net lift generation. In 16 m/s freestream, each wing model showed different lift enhancement characteristics. The PETG wings got the highest lift enhancement to 28% body weight of the pigeon sample. For thrust, PLA wings have great thrust but with nearly double drag, making it a poor propeller. With the same drag level but higher thrust than REAL wings, PETG wings are better propellers than the others.
For 1DOF flapping motion, despite their heavier weight, the artificial feathered wings show some aerodynamic superiority over the REAL wing model. Using artificial feathers to mimic the functions of real feathers is a possible way to improve the flight performance of FWMAV (flapping wing micro air vehicle).
Keywords: Flapping wing, cruising flight, rock pigeon, feathered wing, artificial remiges, aeroelasticity.

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