Effect of pressure on the performance of plasma synthetic jet actuator

The effects of the ambient air pressure level on the performance of plasma synthetic jet actuator have been investigated through electrical and optical diagnostics. Pressures from 1 atm down to 0.1 atm were tested with a 10 Hz excitation. The discharge measurement demonstrates that there is a voltage range to make the actuator work reliably. Higher pressure level needs a higher breakdown voltage, and a higher discharge current and energy deposition are produced. But when the actuator works with the maximum breakdown voltage, the fraction of the initial capacitor energy delivered to the arc is almost invariable. This preliminary study also confirms the effectiveness of the plasma synthetic jet at low pressure. Indeed, the maximum velocities of the precursor shock and the plasma jet induced by the actuator with maximum breakdown voltage are independent of the ambient pressure level; reach about 530 and 460 m/s respectively. The mass flux of the plasma jet increases with ambient pressure increasing, but the strength of the precursor shock presents a local maximum at 0.6 atm.