Discharge characteristic of multiple needles to plate dielectric barrier discharge in gas-liquid mixture

In order to further understand the mechanism and characteristics of dielectric barrier discharge (DBD) in gas-liquid mixture, the electrical and optical characteristics of DBD in gas-liquid mixture with multiple needles to plate electrode structure were measured. The changing trends of electrical parameters and intensities of the main particles with the applied voltage were studied. Moreover, the equivalent electrical model for DBD in gas-liquid mixture was established according to experimental results, and it was used to analyze the experimental results. Results show that the discharge characteristics of DBD in gas-liquid mixture are similar to those in pure gas, but the impact of liquid resistance on the discharge should be taken into account. Its discharge current is in resistance-capacitance type, whose phase angle leads that of voltage less than 90°. A large number of N₂, O, OH, and other high-active particles are produced in gas phase of the discharge, and the discharge power, transmission charge, electron density and the main discharge parameters increase with the increasing of applied voltage but the gas capacitance decreases with the increasing of applied voltage. When the applied voltage is 20.5 kV, their values are 78 W, 1 060 nC, 1.87×10¹¹ cm^-3,and 8.07 pF, respectively. The gas discharge can be equivalent to a voltage-controlled current source (VCCS), resistance and variable capacitance, and the liquid can be equivalent to a variable resistor, whose value is calculated to be 825 Ω before discharge.