Effect on near-wall region flow by an array of dielectric barrierdischarge plasma actuators

In order to reveal the flow state dependence of the control effect by alternating current surface dielectric barrier discharge (AC-SDBD) plasma actuation, an array of eight AC-SDBD plasma actuators was designed, and the influence on the flow in the near-wall region was investigated for the mainstream velocity ranging from 20 m/s to 80 m/s. The experimental results show that the array of AC-SDBD plasma actuators can significantly increase the velocity in the near-wall region initially, which eventually drops a bit before finally stabilizes. After the flow reaches a new stable state, the influence range of the plasma actuation can extent as far as 170 mm downstream of the actuators and 10 mm in the wall-normal direction, respectively. Moreover, the velocity distribution near the wall under the plasma actuation depends on the streamwise and wall-normal locations. When the mainstream velocity is small, the plasma actuation increases the near-wall velocity after stabilization, but when the mainstream velocity is above a certain value, the near-wall velocity after the plasma actuation is lower than the corresponding no actuated case.