三維拍翼昆蟲在陣風條件下滯空飛行之數值模擬

Numerical simulation of 3-D flapping-wing insect's hovering flight under gust wind situations

杭亮同(Liang-Tong Hang)

指導教授 ： 宛同

淡江大學/工學院/航空太空工程學系碩士班/碩士(2014年)

https://doi.org/10.6846/TKU.2014.01040

摘要

論文名稱：三維拍翼昆蟲在陣風條件下滯空飛行之數值模擬
校系所組別：淡江大學航空太空工程學系熱流組
畢業時間及提要別：102學年度第2學期碩士論文提要
研究生：杭亮同 指導教授：宛 同
論文提要內容：
隨著不斷創新的研究及技術上的突破，航太科技正飛快的發展，其中拍撲翼為目前熱門且新穎的研究題目之一。重量輕、靈巧性強、不斷隨時間改變的升阻力皆是拍撲翼主要的特色。根據達爾文的生物演化論，我們可以粗略的認定每種生物行為都是一種最佳化的結果，故將仿生學結合數值模擬的研究則顯得相對重要。許多學者皆投入心力於拍撲翼的研究但大都只考慮單純的懸停及飛行而忽略大氣環境的影響。本研究團隊長期研究天氣影響之因素，累積豐富的分析經驗在不同的氣候環境，在本論文中吾人將探討不同陣風對於拍撲翼空氣動力的影響。此處我們是利用商用軟體ANSYS/FLUNET之動態網格機制來模擬翅膀的拍動，再利用C++編輯UDF結合Solver去模擬陣風下飛行的空氣動力性能。
本研究首先是先與學長及Wang, J.的研究論文所提到的二維板片八字形運動做比對驗證的工作。完成二維的驗證後再根據Dudley Robert的生物實驗研究資料選用Morpho peleides 此種蝴蝶，利用繪圖軟體PRO-E 繪製擬真三維蝴蝶外形並且利用商用軟體Gambit及ANSYS產生動態網格再結合UDF模擬出蝴蝶拍動飛行。之後參考Lian, Y.及Yang, G.等人之研究分別建立單頻率其多頻率之模擬風場進而分析三維蝴蝶在不同風場之下的空氣動力性能。根據吾人可知: 蝴蝶飛行受上下方向風場作用的影響極為劇烈，其升力係數差距可達十倍以上；由於吾人固定蝴蝶身體的俯仰角，故在定量分析上會存在誤差，吾人認為這來自於模擬前不自然的假設，但在定性的物理分析上，不論是壓力及渦度上的結果皆可充分詮釋蝴蝶的空氣動力性能。若是未來加上蝴蝶飛行時身體俯仰角的改變以及柔性結構的考量，將會增加計算結果的精準度。
關鍵詞: 三維拍撲翼，動態網格，風場，UDF

關鍵字

三維拍撲翼 ； 動態網格 ； 風場 ； UDF

並列摘要

Title of Thesis: Total pages: 76
Numerical simulation of 3-D flapping-wing insect's hovering flight under gust wind situations
Keywords: 3-D Flapping Wing, Dynamic Mesh, Gust, UDF
Name of Institute: Graduate Institute of Aerospace Engineering, Tamkang University
Graduate Date: June 2014 Degree Conferred: Master
Name of Student: Liang-Tong Hang Advisor: Dr. Tung Wan
杭亮同 宛 同 博士

Abstract:
With advance of science and technology, the development of aerospace technology progress fast. Flapping-wing is a popular and innovative topic. Based on Darwin's theory of evolution; we can have a general interpretation of each biological behavior patterns are the results of optimization. So it is important to combines aerodynamics and Bionics. Many researchers put effort into study the unsteady aerodynamics and flapping flight but study in flapping-wing Affected by atmospheric environment is much less. Our research team has studied the impact of weather factors for a long time and extensive lots experience in the analysis of different climatic conditions. In this thesis, we will discuss effect of flapping wings for aerodynamics in different gust. Here we use the dynamic grid mechanism of commercial software ANSYS / FLUNET to simulate flapping-wings, edit UDF in C++ and combine Solver to analysis aerodynamic performance under gust. First, we finish the validation of 2-D elliptic flapping wing section with Wang, J. We build 3D model butterfly which species is Morpho peleides Butler by PRO-E. From the morphological data of Morpho peleides is measured by Dudley. We generate mesh by Gambit and ANSYS and use dynamic mesh mechanism of ANSYS / FLUNET to simulate the butterfly forward flight. According to Liang and Yang, we create two type of the gust function with single and multiple frequencies. We analysis the butterfly under different gust and different directions and find lift coefficient is sensitive for the gust from top and bottom. The mean value of lift coefficient can be increased more than tenfold compared with the case without wind effects. And since the assumptions we make, our results may occur tolerance in quantitative values but it is worth referencing in Qualitative physical interpretation. If possible, consider the pitching oscillation of body and the flapping-wing with flexible in the future will improve accuracy of the results.

並列關鍵字

3-D flapping wing ； dynamic grids ； gust effect ； UDF

參考文獻

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[14] Wang, R. L., “Numerical Simulation of Flapping Airfoil in Gusty Environments,” Tamkang University, 2012