Characteristics of ionic wind in needle-to-ring corona discharge

The characteristics of ionic wind of DC corona discharge are investigated in needle-to-ring configuration. The effects of the discharge parameters including the voltage polarity, the overvoltage and the electrode gap are studied experimentally. The results show that the ionic wind has a velocity of several m/s. The ionic wind in the center increases linearly with the overvoltage due to the larger Coulomb force obtained from the electric field and the slope of velocity-overvoltage plot depends on the electrode gap. The ionic wind in the positive corona has a larger velocity in the central part while the ionic wind in negative corona distributes more homogeneously. But the voltage polarity has little influence on the conductance of the discharge channel. A theoretical description is deduced from the basic physics and can express well the correlations between the ionic wind velocity and the discharge parameters.