双翼尖涡Rayleigh—Ludwieg不稳定性实验研究

采用一种结构化矩形直机翼涡发生器产生一对大小不同、方向相反的翼尖涡，调节双涡涡量的大小比例Г1／Г2及其间距b，触发两涡Rayleigh—Ludwieg不稳定性。实验采用流动显示方法定性观察双涡相互作用过程，通过二维PIV（粒子成像测速）系统定量研究双涡相互作用特征，得到双翼尖涡中主涡及次涡的运动特性、环量-时间特性。对不同实验参数下残余环量比例进行分析，发现双涡涡量大小比例Г1／Г2在1．3～1．4、b为50ram时双涡相交削弱效果良好，能够实现翼尖涡强序削弱程度扶30％～40％。

Dual wingtips vortexes Rayleigh-Ludwieg instability experimental research

A generic model with rectangular wings is designed to produce a pair of vortexes that have different strengthes and opposite signs. Adjusting the two vortexes dimension ratio Г1/Г2 and the vortexes distance b to trigger the Rayleigh-Ludwieg instability. Use flow visualization method to display the two-vortex formation and interaction processes. Through the two-dimen- sional particle image velocimetry system, the characteristics of Rayleigh-Ludwieg instability are studied to obtain the motion characteristics and the circulation-time curve of the dual vortexes. The residual circulation ratios under different experimental parameters are also analyzed. A better vortex strength reduction is discovered as Г1/Г2 is between 1.3-1.4 and b is 50mm, and the vortex strength is reduced by 30 %-40%.