In the present study, phase-locked tomographic particle image velocimetry measurements are performed to obtain the complex three-dimensional vortex system created by the interaction of plasma synthetic jets with external crossflow. Three orifice configurations (round, transverse slot, and longitudinal slot) are investigated. For the round orifice case, the vortex system consists of a starting vortex ring surrounding the jet head, a hanging vortex pair residing in the two lateral sides of the jet body, several shear layer vortices bridging the two legs of the hanging vortex pair, and a hairpin vortex induced by the low-speed secondary jet. For the slot orifice cases, the above vortex system is also present; nevertheless, the interconnections of the vortices are further intersected by the rib vortices that are branched out of the elongated vortex ring during axis switching. The counter-rotating vortex pair observed in the far field is essentially evolving from the hanging vortex pair in the near field.

中文翻译：

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等离子合成射流在横流中产生的三维涡结构

在本研究中，进行锁相断层扫描粒子图像测速测量，以获得由等离子体合成射流与外部横流相互作用产生的复杂三维涡流系统。研究了三种孔口配置（圆形、横向槽和纵向槽）。对于圆形孔口情况，涡流系统由围绕喷头的起​​始涡环、位于喷气体两侧的悬挂涡对、桥接悬挂涡对两条腿的几个剪切层涡组成，以及由低速二级射流引起的发夹涡。对于狭缝孔口的情况，也存在上述涡流系统；尽管如此，在轴切换期间，从细长的涡环中分出的肋状涡流进一步与涡流的互连相交。在远场观察到的反向旋转涡对基本上是从近场中的悬垂涡对演化而来的。