Corona discharge effect on charge and energy transfer in dielectric barrier discharge

To study characteristics of corona discharge effect on dielectric barrier discharge (DBD) with small curvature radius electrodes, two sets of comparative experiments were conducted on plate-plate with multi-needle-plate electrode structures and plate-plate with microcavity-plate electrode structures. At first, V-Q Lissajous figures were employed to analyze the air-gap voltage and charge transport in the first part of the experiment, and the result showed that the transferred charge of the multi-needle-plate electrode structure was about 1.5 times that of the plate-plate structure under the same power consumption. The second part of the experiment verified the above result, that is, the corona discharge effect on the microcavity produced a greater amount of transferred charge. Then, a reduced electric field was adopted to analyze the variation of average electron energy and the difference in molecular vibration temperature, and the corona discharge effect of the needle electrode on transfer of charge and energy are discussed. It was revealed that, in the non-uniform electric field of DBD, the local reduced electric field of the electrode tip with small radius of curvature was up to 750 Td, but the reduced electric fields in most of the air gaps were far lower than those of the plate-plate structure. Therefore, the average electron energy around the electrode tip was about 13 eV, which facilitates the collision and ionization of the electrons in air and the production of a large amount of charge. However, in this case, the temperature of molecular vibration was lower, and the excited particles generated in the discharge process were less than those generated by the plate-plate structure.