Control of Jet by the Coaxial Type DBD Plasma Actuator

― Change Vortex Structure of Jet by Burst Actuation ―

Abstract

  In this study, jet control using the coaxial type DBD plasma actuator (=DBD-PA). DBD-PA was driven by burst modulation to control the jet of Reynolds number 1000 ～ 10000. As a result, the phenomenon of lock-in occurred in that the vortex synchronized with the burst modulation drive frequency of the DBD-PA. By driving the DBD-PA with burst modulation, it is possible to generate the axisymmetric vortex at an arbitrary frequency by the phenomenon of lock-in of the jet. In addition, the phenomenon of lock-in arise that two axisymmetric vortices are stably paired and the streamwise vortex grows large. At lower burst modulation drive frequency where the phenomenon of lock-in occurs, separately generated are vortices due to the induced flow of DBD-PA and instability of the shear layer exerted by vortex of induced flow. At higher burst modulation drive frequency where the phenomenon of lock-in occurs, some small fine vortices are scattered.