Effects of Sweep Angles and Angles of Attack on Junction-Flow Patterns

Kuo-Ching San ； Ying-Zong Lin ； Shun-Chang Yen

《Journal of Marine Science and Technology》 預刊文章 Pp. 48-53

https://doi.org/10.6119/JMST-013-0325-1

並列摘要

This study utilized the NACA 0012 finite wings to investigate the effects of wing sweep angle (Λ) and angle of attack (α) on the junction vortex at Re = 8 × 10^4. The junction-vortex structures were visualized using the surface oil-flow visualization. The junction vortex is classified as-separation, attached, bubble, and bluff-body wake modes. The separation mode occurs at Λ ＜ 12° and α ＜ 5°. The attached mode occurs at low α for a swept-back wing (Λ ＞ 0°) and the bluff-body wake mode occurs at high α for a forward-swept wing (Λ ＜ 0°). Furthermore, the bubble mode occurs at high sweep angle (i.e., high backward sweep angle) and high angle of attack. Furthermore, the properties of velocity vectors, normal stress and shear stress are also detected and analyzed using an X-type hot-wire anemometer.

並列關鍵字

wing junction ； junction vortex ； oil flow ； sweep angle

參考文獻

Devenport, W. J., Agarwal, N. K., Dewitz, M. B., Simpson, R. L., and Poddary, K., “Effects of a fillet on the flow past a wing-body junction,” AIAA Journal, Vol. 28, pp. 2017-2024 (1990).

Gand, F., Deck, S., Brunet, V., and Sagaut, P., “Flow dynamics past a simplified wing body junction,” Phys. Fluids, Vol. 22, pp. 115111 (2010).

Hwang, J. Y. and Yang, K. S., “Numerical study of vortical structures around a wall-mounted cubic obstacle in channel flow,” Phys. Fluids, Vol. 16, pp. 2382-2394 (2004).

Lin, C., Ho, T. C., and Dey, S., “Characteristics of steady horseshoe vortex system near junction of square cylinder and base plate,” ASCE Journal of Engineering Mechanics, Vol. 134, pp. 184-197 (2008).

Olcmen, S. M. and Simpson, R. L., “Influence of wing shapes on surface pressure fluctuations at wing-body junctions,” AIAA Journal, Vol. 32, pp. 6-15 (1994).