三角翼前缘涡的某些破裂形式及特性研究

基于流动显示和PIV技术测量的实验结果，对三角翼前缘涡破裂的一些形式和破裂特性进行了分析和讨论。通过PIV测量所得到的涡量分布证实了在螺旋破裂的情况下，涡核的螺旋方向与前缘涡的旋转方向相反，及双螺旋破裂形式的存在等。进而对螺旋波的形成机理提出了与有关文献不同的看法。

Study on some breakdown forms and characteristics of leading edge vortex over delta wings

Since the discovery of vortex breakdown phenomenon, many theoretical and experimental studies have been conducted. However, up to date the understanding of vortex breakdown is not enough or comprehensive. Vortex breakdown is an unsteady process and a breakdown vortex has very complex structure. The vortex breakdown phenomenon is concerned with a fighter aerodynamic characteristics and buffeting. Farther investigation on the vortex breakdown phenomenon is very important. It is well known the dominate vortex breakdown forms over delta wings are spiral and bubble form. However many other forms of vortex breakdown have been found in the vortex flow in a tube. A lot of flow visualization on vortex breakdown over delta wings show that the spiral breakdown form is a dominant form. Others have found that there are two new forms of vortex breakdown: one is double spiral and another is filiform spiral form, which appears on delta wings with smaller sweep angle. Recent years particle image velocimeter (PIV) technique is developed rapidly and applied in flow measurement. At certain degree quantitative measurement of vortex breakdown phenomenon could be conducted. Based on experimental results of flow visualization and PIV measurement some breakdown forms and characteristics of leading edge vortices over delta wings are analysed and discussed in this paper. It is shown that for spiral breakdown the helix sense of the vortex core is opposite to the direction of the main vortex rotation and double spiral vorticity distribution perpendicular to the vortex axis is identified. Besides that different idea from existed explanation in lot of papers about spiral wave mechanism in breakdown vortex flow is also presented.