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標題: | 偏離角與攻角對於豆娘(短腹幽蟌)飛行表現與功率之影響 The Influence of Deviation Angle and Angle of Attack on Flight Performance and Power Consumption of Euphaea formosa |
作者: | Tzu-Hen Tsai 蔡子珩 |
指導教授: | 楊鏡堂(Jing-Tang Yang) |
關鍵字: | 豆娘飛行,偏離角,拍撲軌跡,功率,拍撲型無人微飛行器, damselfly flight,deviation angle,flapping trajectory,power consumption,flapping micro aerial vehicle, |
出版年 : | 2020 |
學位: | 碩士 |
摘要: | 本研究藉由高速正交攝影技術擷取豆娘(短腹幽蟌)前飛時翅膀與身體的動作,並以此建立三維非穩態數值分析模型,利用實驗室前人研究的自由飛行速度數值分析,探討偏離角的改變對於豆娘的飛行速度、翅膀升阻力、飛行軌跡以及功率等因素的影響,並且從固定來流、自由飛行、單翅或雙翅各方面切入探討,以期望未來應用於無人飛行器之設計上。 偏離角為翅膀偏離拍撲平面的角度,因此改變偏離角就會改變翅膀的拍撲軌跡。本研究主要分為後翅8字形拍撲與後翅O字形拍撲,前翅則動作固定,比較後翅改變偏離角後對於升阻力的影響。數值分析結果顯示O字形拍撲在上拍時拍撲軌跡與拍撲平面平行,且從豆娘前飛影片中擷取到的O字形拍撲在上拍時攻角會接近垂直,兩個因素造成O字形拍撲有最好的推力,而且消耗功率較低,因此在前飛比較常見;一般文獻提到的8字形拍撲,本研究的分析結果與文獻相似,升力較高,但也發現其推力不如O字形拍撲,消耗功率也比較高,利於上升飛行,且8字形在上拍攻角接近垂直時,攻角已經極高,再增加有效攻角將無法產生更高的升力。 偏離角振幅將會影響拍撲軌跡的寬窄,因此本研究也對於8字形拍撲與O字形拍撲模式分別調整偏離角振幅的影響,偏離角振幅將會影響該字形的寬度。而結果顯示8字形在偏離角振幅越大時,升力也會提高,但耗功也會增加,且效率會減少;而O字形在偏離角振幅越大時,升力反而減少,且耗功也會增加,因此效率大幅遞減。所以推斷在應用時,若有必要可以增加8字形的偏離角振幅以提昇升力,但O字形則約在偏離角振幅為3度時比較理想。 本文藉由偏離角的各種情況與參數的數值分析結果,整理出在各個飛行模式下如前飛與上飛時最理想的偏離角函數,可作為拍撲型無人飛行器機構的動作參考。 The effects of deviation angle on flight performance and power consumption were studied by high speed photography and 3-D transient numerical analysis. The motion of Euphaea Formosa, a damselfly species, was recorded by two orthogonally-aligned high speed video cameras. In this study, the single-hindwing model and the tandem-wings model based on the recorded motion were used in 3-D numerical simulations of static, fixed and freestream flow fields. The results could be helpful for the design of MAVs (Micro-aerial-vehicles). Deviation angle is the angle of the wings deviating from the stroke plane. Adjusting deviation angle leads to the change of wing flapping trajectory. This study mainly discussed the ellipse and figure-eight shaped flapping trajectories of the hindwings. The motion of forewings is fixed, as recorded by the cameras. The results show that the thrust of ellipse flapping trajectory model was greater and the power consumption was lower than those of the figure-eight shaped flapping trajectory model, and thus should be applied in forward flight. In the up stroke, the direction of the ellipse flapping trajectory was parallel to the stroke plane. In addition, the recorded videos revealed that the angle of attack in ellipse flap was nearly perpendicular in the upstroke. We discovered that these two factors contributed to the thrust of ellipse flapping trajectory model. Besides, the results showed that the figure-eight shaped flapping trajectory model had greater lift, which had been suggested by the literature. We also found when the angle of attack in the figure-eight shaped flapping trajectory was almost vertical, it would not generate more lift due to excessively high angle of attack. The amplitude of the deviation angle was also discussed in the figure-eight shaped model and ellipse model respectively. The amplitude influences the width of the trajectories. The results showed that lift and power consumption increased as the amplitude of the deviation angle in the figure-eight shaped model increased, and thus could be applied to the MAVs when lift was urgently needed. However, increasing the amplitude of the deviation angle in the ellipse model increased power consumption and reduced lift. Therefore, there was no benefit from taking this action in the ellipse model. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/8102 |
DOI: | 10.6342/NTU202004223 |
全文授權: | 同意授權(全球公開) |
顯示於系所單位: | 機械工程學系 |
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