Flow characteristics of a rectangular jet with DBD plasma actuators at nozzle exit

Abstract

The objective of this study is to establish an active flow control method for a 2:1 rectangular jet using a dielectric barrier discharge plasma actuator (DBD-PA) installed at the exit of a nozzle. These additional devices are able to change the velocity distribution of a jet stream by adding an induced flow to the airflow ejected from a rectangular nozzle. These DBD-PA were placed on the short and long sides, and on the four corners of the nozzle exit. The rectangular nozzle had a height of 30 mm and a width of 60 mm. The Reynolds number of the jet was 9,000. The flow field was measured by particle image velocimetry (PIV). The flow field was visualized by tracer injection method. The DBD-PA has an influence on the formation of the large-scale vortical structure in the share layers of the rectangular jet. For the jet with DBD-PA on the long sides of the nozzle, the length of potential core increases more than that with DBD-PA on the short sides and the four corners of the nozzle. The spread of a rectangular jet in the x-z cross-section is significantly affected by the DBD-PA installed at the short sides and the four corners of the nozzle.