低雷诺数非细长三角翼绕流流动结构实验研究

通过水洞流动显示实验对低雷诺数非细长三角翼绕流流动结构进行了研究,特别是前缘剖面对50°三角翼绕流涡结构的影响及存在双涡结构时模型的最大后掠角.实验表明,双涡结构对染色液的注入位置很敏感,且这一双涡结构现象在64°三角翼绕流中仍可观测到;此外,前缘剖面形状严重影响涡破裂位置及涡核的空间分布.与迎风面倒角前缘相比,背风面倒角的三角翼易于产生双涡结构、可以推迟涡破裂并使涡核靠近模型上表面,进而有利于提高三角翼的气动特性.

Experimental investigation on flow structures over nonslender delta wings at low Reynolds numbers

The water tunnel flow visualization was conducted to investigate the flow structures of nonslender delta wings at low Reynolds number. The experiments were focused on the effect of leading-edge cross section on vortex structures for 50° sweep delta wings and on the maximum sweep angle at which the dual vortex structure exists. It is obtained that the dual vortex structures are sensitive to the dye injection location, and such structure can be observed at sweep angle as large as 64°. Meanwhile, the experimental results indicate that the leading edge cross-section significantly influences the vortex breakdown position and the trajectory of the vortex core. In comparison with the windward beveled leading edge, the leeward beveled one is easy to generate the dual vortex structure over the 50° sweep delta wing, to delay the primary vortex breakdown, and cause the primary vortex core close to the wing surface, which are benefit to improve the aerodynamic characteristics of the delta wing.