【作者】 张华； 吕志咏；

【Author】 ZHANG Hua LU Zhi-yong (Instisute of Fluit Mechanics,Beijing University of Astronautics,Beijing 100083,China)

【机构】 北京航空航天大学流体力学研究所,流体力学教育部重点实验室；

【摘要】 利用 PIV 测试技术从定量的角度实验证实了角区干扰马蹄涡在一定条件下存在着有别于传统"分离奇点"的"附着奇点结构",即对称面最上游的流线并非是从壁面向上抬起而从壁面"分离",而是经由空间的一个奇点向壁面"附着",从而表明表面油流显示中的渐进收拢线可能是附着线而非分离线,因而油流渐进收拢线只是分离的必要条件而非充分条件。PIV 实验结果还表明角区干扰马蹄涡存在着三种可能的附着奇点结构,三种附着奇点结构都满足奇点指数拓扑法则。更多还原

【Abstract】 The PIV experimental results confirm the existence of an outmost attachment saddle point structure of the horseshoe vortex in juncture flow.The new structure is different from the traditional separated saddle point structures.For one,two and three main horseshoe vortex conditions the outmost streamline doesn’t rise from the plate but attaches to the plate pass through a space singular point.The results infer that progressive convergent line in surface oil visualization may not be the separation line but the attachment line,so that the progressive convergent line in sudace oil visualization is not the sufficient condition but the necessary condition for 3-D separation.The PIV results also show that there are three possi- ble new topological structures with the outmost attachment singular point.These three new structures satisfy the topological singular point index rule.更多还原