The vortex structure of synthetic jet in a crossflow

Abstract

Synthetic jets are produced by periodic ejection and suction of fluid from an orifice induced by movement of a diaphragm inside a cavity, and a synthetic jet actuator is a useful tool for active flow control. The synthetic jet actuators are low operating power, zero-net-mass-flux and very compact devices which have demonstrated their capability in modifying the subsonic flow characteristics for boundary layer flow control. In the present study, a smoke flow visualization was used to reveal the characteristics of the vortical structures produced by a synthetic jet in a crossflow. A significant difference was observed in the flow field for the synthetic jet issuing into the crossflow by changing dimensionless stroke length. The deformation of the vortex ring in the boundary layer promotes at high dimensionless stroke length. The flow structure generated by the interaction between the synthetic jet and the crossflow was affected by the dimensionless stroke length.