Flow control around a pitching oscillation circular cylinder using a dielectric barrier discharge plasma actuator

This paper discusses flow control around a stationary and pitching oscillation circular cylinder using a dielectric barrier discharge plasma actuator (PA). The pressure on the cylinder surface was measured to determine the lift and drag forces on the cylinder, and the differences between these values were investigated with and without the PA actuations. The results indicated that the time-averaged lift force increased by up to 140% for the 180 degrees rotating cylinder. Additionally, the effect of the PA on the lift-hysteresis curve of the pitching cylinder were evaluated based on the temporal variation in the surface pressure. Moreover, to investigate the effect of the PA on the flow field, smoke wire and LED-PIV methods were used to visualize the flow around the cylinder. The results showed that PA promotes the mixing between the freestream and separated flow which makes the separated shear layer thicker for both stationary and a pitching oscillating cylinder. For the pitching oscillating cylinder, the flow fields modified by PA actuation are different depending on the direction of the rotation of the cylinder. These results indicate that PA enhances the circulation of the flow around the cylinder.