本研究以沉浸邊界法模擬果蠅翅膀在不同運動方式下的飛行表現。欲進行比較的運動方式有：真實的果蠅飛行運動，以及自果蠅運動簡化而來的旋轉對稱運動(Symmetric rotating motion, SYR)。其中，果蠅翅膀抬升(elevation)或下沉的偏軌行為對飛行表現的效益為何也是探討的重點。我們以翅膀因運動而產生之升力及阻力來評斷此運動的表現。初步結果顯示：真實的果蠅運動能產生比簡化後的版本更大的升力，同時會承受比較小的阻力。此外，翅膀的抬升與下沉能借由改變瞬時攻角(instantaneous angle of attack)有效地為果蠅在飛行過程中維持良好的升力。我們會以翅膀周圍的渦流狀況來解釋不同時間下的比較結果；此外，我們也會介紹之前文獻曾提出的機制，並也以這些機制解釋比較結果。近年來，微型飛行機械(Micro air vehicle, MAV)受到許多關注，因此以模擬的方式快速並正確地預測拍動翅膀之飛行表現是本研究的目的，也期許對MAV的設計有參考之價值。

The immersed boundary method (IBM) is adopted to explore the flying performance of an insect-like wing with different kinematic profiles. Realistic wing motions based on fruit flies are compared with symmetric rotating motion, which is a simplified motion that mimics the fruit fly motion. Whether the elevating of the fruit-fly wing is beneficial is also considered. Aerodynamic performance is determined according to lift and drag generations. The results show that the realistic fruit-fly motion can generate a stronger lift with a lower drag than symmetric rotating motion. The elevating motion can also prevent the drop of the lift by affecting the instantaneous angle of attack. The results are explained by illustrating the vortex contours, and the mechanisms related to flying performance are also introduced. The purpose of this simulation is to rapidly predict the aerodynamic performance of an insect-like wing since micro air vehicles (MAVs) have gained considerable interests in recent years. Thus, a valid prediction at MAVs’ design stage is important.

Abstract
Contents
Introduction..............................6
Numerical Methods........................11
Numerical results and discussion.........28
Conclusion...............................37
Bibliography.............................38

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