飛航安全在航空界從來就是一個非常重要的課題。在眾多影響飛航安全的因素中，當兩架飛機飛的極為靠近，前面飛行之飛機其尾隨渦流極易影響到後面飛機之操控，進而使隨行在後之飛機失控而產生事故，這種飛安事件在起降頻繁機場是極為易見的。
　　本研究以實驗方式探討有限機翼產生之下洗尾流的發展及特性，並研究其對下游飛機動態的影響。在研究下洗尾流發展及特性，實驗使用翼剖面NACA0012展弦比為3的有限長矩形翼為測量模型。並將其作為渦流產生機翼，尾隨機翼模型使用矩形平板展弦比為4，研究尾流效應影響下尾隨機翼之動態響應。實驗風洞的風速20m/s，雷諾數Re=9.63×105，攻角取5∘、12∘，藉由X型熱線測速儀得流線方向及垂直方向的瞬時速度，經由資料分析，討論下洗尾流及翼尖渦流的結構及發展情形。固定渦流產生機翼攻角為12∘時，進一步量測架設於風洞內尾隨機翼的動態行為，探討在不同的尾隨渦流效應下，尾隨飛機所受流場的穩定效應，及其所能承受之六力的動態響應。隨著尾隨機翼的固定位置改變，翼尖渦流對其所造成的影響也會有相對的改變。在升力方面，尾隨機翼因為翼尖渦流流過翼表面上方或下方造成升力上升或下降。飛機動態穩定的俯仰力矩跟轉動力矩，更因為尾隨渦流流過之位置不同而有不穩定的改變。

　　Concerning the world aviation industries, the flight safety is always one of the most important factors to be considered. For accident/incident investigations in flight safety, trailing vortex behind an aircraft may usually result in a strong downwash effect, which will extend downstream for miles behind the plane and pose a potential hazard to the following-up aircraft, in particular, at take off and landing. The accidents caused by the existence of the trailing vortex with high turbulence intensity are frequently met in the busy airports. Therefore, keeping a safe separation distance between two aircraft is very important.
　　The present research is intended to investigate the cause and effect of the trailing vortices and to study how these vortices affect or influence the following-up airplane by experimental approach. The wing model having the NACA0012 airfoil section of AR=3 is used as a wake generating model, which is followed by a plate flat wing of AR=4. The freestream velocity is operated at 20m/s with the corresponding Reynolds number of 9.63×105 based on the front wing chord. The angle of attack (AOA) of the front wing model is maintained at 5∘and 12∘throughout the experiments. The wake development is obtained by the measurements of streamwise and transverse information through a cross-type hot-wire anemometer. To investigate the dynamic response of the following wing due to the existence of the tip vortices or wake from the front wing model, the relative position of the following wing model is varied with respect to the front wing in spanwise direction. The results indicate that the aerodynamic lift of the following wing is drastically affected due to the impingement of the tip vortices or wake from the front wing. It is very obviously to show as well that the following wing will behave unstable features due to the unbalanced situation of the rolling or pitching moments, which have strongly illustrated that a small aircraft incidentally flies into a strong wake region generated from a large aircraft will clearly pose some measures of hazards in aviation safety in the present study.

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