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標題: | 撓性與翅腹動作相位差對仿蝴蝶機構升推力之影響 The Impact of Flexibility on Lift and Thrust Generated by Butterfly-inspired Mechanism in Varied Wing-abdomen Motion |
作者: | 鄭家枏 Chia-Nan Cheng |
指導教授: | 楊鏡堂 Jing-Tang Yang |
關鍵字: | 仿蝴蝶機構,撓性,腹部擺動,粒子影像測速,渦漩, butterfly-inspired mechanism,flexibility,abdomen oscillation,particle image velocimetry,vortex, |
出版年 : | 2022 |
學位: | 碩士 |
摘要: | 本文旨在利用仿蝴蝶拍撲機構重現真實蝴蝶的飛行姿態,藉由粒子影像測速法解析流場,探討三種撓性程度的翅膀在五種翅腹動作下對升推力的影響,期望應用於拍撲翼微飛行器的開發。 本文首先進行生物動態拍攝實驗,利用三台高速攝影機同步拍攝大白斑蝶(Idea leuconoe)之前飛動態,研究樣本數為四,共採計七組數據,以大白斑蝶在一個拍撲週期內的拍撲角、掃掠角及腹部擺動角動作函數,作為仿蝴蝶機構之馬達輸入。 仿蝴蝶機構的翅膀以真實蝴蝶翅膀外型為基礎,尺寸放大2.8倍,符合幾何相似性、運動相似性及動力相似性原則,材質選用碳纖維、PETG及PLA三種。透過前後平移真實蝴蝶的腹部擺動角動作函數,建立相位延遲0.2週期、相位延遲0.1週期、相位正常、相位領先0.1週期及相位領先0.2週期五種翅腹動作相位差,作為仿蝴蝶機構之運動設定。 本文發現因PLA翅與PETG翅具有撓性,翼尖處會彎折並造成流場局部真空,誘使周圍氣流流入補充,故能吸住產生的翼前緣渦漩,並且引導翼前緣渦漩順著翅膀的弧度分布,讓其在拍撲過程中能穩定貼附、不易脫落。 在三種撓性程度翅膀的比較中,結果顯示撓性中等的PLA翅在升推力皆有最佳表現,分別有19.85 %的升力增幅和103.59 %的推力增幅。在五種翅腹動作的比較中,結果顯示相位延遲0.1週期案例與相位延遲0.2週期案例之渦漩環動量比相位正常案例大,增幅分別為103.07 %和47.44 %,證實相位延遲案例能產生較大瞬間作用力。 本文透過渦漩環理論分析仿蝴蝶機構在各種運動條件下的升推力表現,在翅膀撓性的選擇上,建議裝配PLA翅,在飛行穩定性的考量上,建議採用相位正常策略,但若需大瞬間作用力來改變飛行軌跡,則應該改用相位延遲0.1週期策略。 This study reproduces the flight posture of the Idea leuconoe by using a butterfly-inspired mechanism and analyzes the flow field by the particle image velocimetry in order to explore the impact of wing flexibility on lift and thrust generated by the butterfly-inspired mechanism in varied wing-abdomen motion. It is expected to be applied to the development of flapping-wing micro aerial vehicles. We first use three high-speed cameras to capture images of the butterfly’s forward flight synchronously. Seven sets of data are collected in total. Then we utilize the flapping motion function, lead-lag motion function and abdominal oscillation function analyzed from butterfly’s movement as the input of the butterfly-inspired mechanism. The wing sizes of the butterfly-inspired mechanism are 2.8 times larger than those of the real butterfly. Three materials, the carbon fiber, PETG and PLA, are chosen for three kinds of wing flexibility. By keeping the wing motion function the same and translating the abdominal oscillation function back and forth, we construct five kinds of wing-abdomen motion, which are “delayed 0.2 t/T”, “delayed 0.1 t/T”, “normal”, “advanced 0.1 t/T” and “advanced 0.2 t/T”. Because of wing flexibility, the wing tips of the PLA wings and PETG wings bend downward, which creates vacuum locally and induces air inflow for supplement. Therefore, the leading edge vortex will be drawn tightly and then attach on the wings during the flapping motion. In the comparison of three kinds of wing flexibility, the results show that the PLA wings have the best aerodynamic performance, 19.85 % in lift increase and 103.59 % in thrust increase respectively. In the cases of “delayed 0.1 t/T” and “delayed 0.2 t/T”, the momentum of vortex ring is much larger than that in the case of “normal”, 103.07 % and 47.44 % in increase respectively. Hence, the cases of “delayed” are proved to generate larger instantaneous aerodynamic forces. This study analyzes the lift and thrust performance of the butterfly-inspired mechanism in various combination of wing flexibility and wing-abdomen motion through the vortex ring theory. It is recommended to assemble the PLA wings on butterfly-inspired mechanism for the choice on wing flexibility. For the flight stability, we suggest to adopt the wing-abdomen motion of “normal” case, while for the purpose of changing the flight trajectory, we suggest to adopt the wing-abdomen motion of “delayed 0.1 t/T” case instead. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/85519 |
DOI: | 10.6342/NTU202201276 |
全文授權: | 同意授權(全球公開) |
電子全文公開日期: | 2023-08-01 |
顯示於系所單位: | 機械工程學系 |
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