Abstract: The flow structure induced by plane and cylindrical shell delta winglet,trapezoidal winglet and rectangular winglet vortex generators(VGs)is investigated with the particle image velocimetry(PIV)to obtain the velocity and vorticity fields.A small rectangular wind tunnel is built to carry out experiments at Reynolds number Re=700 and attack angle α=60°.The results show that the vortex structure of plane and cylindrical shell delta winglets is mainly distributed in the central area of the inclination edge and the corner area of the trailing edge of the VG. For trapezoidal and rectangular winglets,vortices mainly distribute in the wing tip region of the leading edge area and the trailing edge area.Besides,the cylindrical shell trapezoidal winglet induces a central area vortex structure,which has the largest influential area among all types of VGs.The vortex structure induced by the leading edge of trapezoidal and rectangular winglets is generally stronger than that by trailing edge area.As the flow goes on,the strength of vortex structures degrades.Only one main vortex can be maintained along the flow direction in the case of a delta winglet,while one main vortex and one trailing edge corner vortex can be identified in a trapezoidal and rectangular winglet.The vortex structure induced by plane shell winglet tends to get away from the bottom wall,while the vortex structure induced by a cylindrical shell winglet tends to maintain close to the bottom wall.

Key words: vortex generator, particle image velocimetry, flow characteristics, cylindrical shell winglet, plane winglet

摘要： 在Re=700、攻角α=60°时,利用粒子图像测速技术(PIV)研究了矩形通道内平直和柱面小翼诱发的流动结构,获得涡发生器(VG)后1~3倍弦长距离的速度场和涡量场。结果表明,三角小翼的涡结构主要分布在斜边中心和后缘角区;梯形和矩形小翼的涡结构主要分布在前缘翼梢区域和后缘区域;此外,柱面梯形小翼中心区域的涡结构明显,影响范围最大。随着流动的进行,涡结构强度逐渐减弱,三角小翼仅维持一个主涡向下继续运动;梯形和矩形小翼也仅维持一个主涡和一个后缘角涡的结构。随着斜截角的减小,前缘和中心区域诱发高强度涡结构的能力增强,影响范围也广,而后缘角涡的影响范围较小,且与底部壁面的距离较远。

关键词: 涡发生器, 粒子图像测速, 流动特性, 柱面小翼, 平直小翼