バースト駆動を用いたプラズマアクチュエータによるオフセット噴流の制御

抄録

An experimental study is performed on a two–dimensional offset jet with a dielectric barrier discharge plasma actuator (PA) as a flow control device that introduces a periodic disturbance to the system. The offset jet is produced by a flow of air emitted from the end of a long parallel channel, and the plasma actuator is installed on the lower wall of the jet exit, and is operated using burst-modulated or continuous waveforms. The Reynolds number based on the mean velocity and the hydraulic diameter of the inlet channel is 2.0 × 10³, and the flow at the channel exit is laminar. The offset ratio H/h (H: step height, h: channel height) is 1.0.The results show that the reattachment length is reduced and the Nusselt number in the recirculation region increases with the induced flow due to the PA. These effects are remarkable at a burst frequency of 100 Hz, which matches the acceptance frequency of the dividing shear layer. At a duty ratio of D = 50%, due to the existence of a periodic large vortex structure, the reduction of the reattachment length is similar and the Nusselt number is higher compared to those obtained for continuous operation (D = 100%).