双三角翼前缘剖面形状对涡运动的影响

采用数值模拟和理论分析相结合的方法,研究了前缘剖面形状对双三角翼涡运动的影响,分析了前缘剖面形状对三角翼、双三角翼涡运动影响的不同机理 :对三角翼,尖前缘可以形成组织最好的涡结构,但对于双三角翼,圆前缘生成的旋涡结构较靠近翼面,涡结构紧密,诱导能力较强,可以形成有利的涡涡干扰,使内翼涡通过剪切层向外翼涡输入涡量更加容易,合并涡变得更加稳定,推迟了涡破裂,而且由于涡较靠近翼面,因而可以产生较高的非线性涡升力,这同传统的认识是不一致的。

NUMERICAL INVESTIGATIONS OF THE EFFECTS OF DIFFERENT LEADING- EDGE PROFILES ON THE VORTEX FLOWS OVER DOUBLE-DELTA WINGS

The effects of different leading edge profiles on the vortex flows over double delta wings were investigated both numerically and theoretically. And the different mechanisms of the leading edge profiles affecting the vortex flows over both single delta wings and double delta wings were analyzed and contrasted. While over single delta wings, the structures of the vortices resulting from sharp leading edges are organized best, over double delta wings, the structures of the vortices resulting from round leading edges are closer to the wing surface, and are tighter than those resulting from sharp leading edges. This shows that, over double delta wings, round leading edges have stronger inducement abilities, and can constitute more favorable vortices interactions, which makes it easier to transfer vorticity from the inner vortices to the outer vortices through the shear layers. Thus, the combined vortices become more stable, and the vortices breakdown can be well prolonged. Moreover, because they are closer to the wing surface, the vortices resulting from round leading edges can provide a higher nonlinear lift than under other circumstances, which is different from the traditional views.