頁籤選單縮合
題 名 | Static and Dynamic Aerodynamic Comparisons for Stealthy/Conventional Aerial Vehicles in Water Tunnel |
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作 者 | Wang, Shu-wei; Chang, Li-min; Chuang, Shu-hao; Lee, Hsing-juin; Huang, Chien-min; Chien, Kuo-tung; | 書刊名 | Journal of Aeronautics, Astronautics and Aviation. Series A |
卷 期 | 41:4 2009.12[民98.12] |
頁 次 | 頁245-253 |
分類號 | 447.55 |
關鍵詞 | Semblance of stealth; Vortex breakdown/aerocharacteristics testing; Longitudinal/lateral stability; Reduced frequency; Hysteresis behavior; |
語 文 | 英文(English) |
英文摘要 | This paper highlights the water tunnel experiments of both the Boeing X-45A stealth drone model and the traditional NASA TP-1803 model without semblance of stealth, and compares their wing vortex structures and aerocharacteristics for several parameters. The experiments show that the normal force coefficient of the X-45A increases much more than that of the TP-1803 for α<20° in the static processes, and the X-45A has better longitudinal stability than the TP-1803. For α>20°, the Cn of the TP-1803 is larger than that of the X-45A. Further, the longitudinal instability of the X-45A occurs earlier than TP-1803. Further, For α<20° the Cn of X-45A increases rapidly in the pitch-up process, but decreases slowly for the pitch-down process. The dynamic normal fore experiment shows more tremendous hysteresis for the TP-1803 than the X-45A. In addition, the maximum Cm in the X-45A is larger than the TP-1803. Besides, the X-45A's nose pitch-up moment appears reductive for α=30° in the pitch-down process. Yet, larger K result in larger hysteresis loops and the longitudinal instabilities appear clearer. Ultimately, the longitudinal direction presents stable state from α<25° in the pitch-down processes. |
本系統中英文摘要資訊取自各篇刊載內容。