近年來,拍翼之流場為眾多學者研究的目標,但拍翼之三維動態流場研究並未多見,為了要了解翅膀拍動時在上下表面所產生的渦流變化情況,本文利用一類似蝴蝶前翼之簡單拍撲機構,藉由改變頻率及振幅,探討翼面不同位置隨翅膀上下擺動時流場中的渦流變化。利用二維之粒子影像測速儀觀測其三維之動態流場,並繪製成三維渦流變化圖。 實驗結果顯示,在不同的翅膀拍動頻率與振幅條件下,渦流成長及消散之情形類似。而振幅改變之效能最佳。藉由雷射切面之渦流觀測,可知翅膀在下拍時,各位置之渦流截面積差異較大,其翼尖位置渦流較小,中間位置最大,而後渦流截面積變小,此變化可能與翅膀各位置之壓力差相關。
The studies of flapping mechanism have been wide spreaded in recent years. The influence of the controlling parameters on the flapping mechanism was studied in this research. To investigate the vertical flow structure, a biomimetic flapping wing was set up and was used for the experiment. The floe field was observed and analyzed using high speed camera. The captured images showed that the size as well as the strength of the vortex varied with both flapping frequency and amplitude. The size of the leading edge vortex distributed spanwise is larger in mid-section of the wing. The results of the research is helpful in understanding the three-dimension flow field and cab be used for comparison with results of numerical simulation.