無人戰鬥飛行載具（UCAV），具備執行軍事作戰任務的能力，包括偵察、打擊目標等。第六代戰機強調多系統協同作戰能力、隱形設計與高機動性能的結合。Stability and Control Configuration（SACCON） 是其中一個經典的參考構型，為研究無尾翼 UCAV 氣動穩定性與操控性能提供了基礎框架。本研究依據 SACCON 構型進行重建並製作出NCKU UCAV Model，以進一步探討低雷諾數條件下的渦流結構與動態行為。
本研究分為動態與靜態攻角兩層面於低速循環式水洞進行實驗，動態攻角方面使用染液注射法，將翼表面流場結構可視化呈現，觀察UCAV NCKU Model的穩態、擬穩態與非穩態的Reduced frequency(K)特性，並且能夠觀察渦流潰散的位置。靜態攻角方採用粒子影像測速(PIV)，透過單台高速攝影機與雷射光頁捕捉不同翼展截面的流場數據，經由後處理重建三維流場。

This research investigates the vortex dynamics of an unmanned combat aerial vehicle (UCAV) model under low Reynolds number conditions. The primary objectives are to examine the effects of reduced frequency on vortex breakdown and to identify critical vortex structures that influence aerodynamic stability. Experiments were carried out in a low-speed recirculating water tunnel, using both dye injection flow visualization and particle image velocimetry (PIV). The dye injection provided immediate visual evidence of vortex formation, breakdown locations, and quasi-steady flow states, while PIV measurements allowed for three-dimensional reconstruction of the flow field across multiple spanwise sections. Results show that vortex breakdown onset is sensitive to changes in reduced frequency, with certain frequency ranges maintaining quasi-steady vortex structures and others exhibiting significant unsteadiness. These findings underscore the importance of careful aerodynamic design and control strategies for future UCAVs, particularly when operating in low-speed or high-angle-of-attack regimes.

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