Surface Dielectric Barrier Discharge And Its Application In Electric Propulsion

Plasma thruster based on surface dielectric barrier discharge is a novel electricalpropulsive device developed in recent years. It has potential application in the aerospacefield, especially in the near-space technology. This thesis focuses on the dischargecharacteristics of surface dielectric barrier discharge in low-pressure air and the electricpropulsion of this thruster.Firstly, driven by ac high voltage, the characteristics of surface dielectric barrierdischarge in low-pressure air were studied experimentally. The effects of the operatingparameters including the applied voltage, the gas pressure and the electrode configurationswere investigated. The results show that the breakdown and sustaining voltage of thesurface dielectric barrier discharge increase with the electrode distance and the gas pressure.But the electrode dimensions do not affect the breakdown characteristic. The dischargecurrent in both half periods is not symmetric. The current in the positive half cycle has apeak value being obviously larger than that in the negative period, but lasts for a shortertime. The pulsed discharge in both half cycles starts from the edge of the high-voltageelectrode and develops in two directions toward both anode and cathode. The appliedvoltage, the electrode spacing and dimension, the air pressure have some influences on thedischarge current, the charge transfer and the discharge energy.Then, the electric propulsion produced by the surface-dielectric-barrier-dischargethruster was measured under different conditions. It is shown that the propulsion increaseswith the applied voltage. At the same over-voltage, the air pressure in the tested range doesnot affect the propulsion. A narrower high-voltage electrode and a wider groundedelectrode help to improve the electric propulsion of the present plasma thruster.