绕三角翼流态中的某些定常与非定常特性研究

利用流动显示及片光技术,对绕三角翼流动中的某些非定常特性进行了研究。首先在涡面剪切层中发现了两种不同的小涡结构。进而对涡破裂点脉动做了系统的观测,发现在破裂点很靠近顶点的迎角下,脉动主频突然增大。此外还对三角翼涡破裂形态做了细致的分析,提出了泡状破裂在一定程度上可以看成螺旋破裂并给出了实验结果,提出了三种特殊的破裂形态。

Some steady and unsteady structures over delta wings

Flow visualization tests over delta wings with light sheet technique were performed at the water channel of BUAA. The tests have made progress in the following respects: two different kinds of discrete vortices were found in the vortex sheet which emanates from the leading edge of a delta wing. At high angles of attack, the frequencies of vortex breakdown location fluctuation become very high dramatically. Beside spiral and bubble form of vortex breakdown, other three forms of vortex breakdown over delta wings were found in the test. In certain sense it can be said that the bubble type of vortex breakdown is the special case of the spiral type. There is no essential difference between them.