Effect of transverse airflow on the deflection of negative corona discharge on the Trichel pulse mode at atmospheric pressure

Negative corona discharge can deflect in transverse airflow in pin-to-plane electrodes at atmospheric pressure. In this paper, we investigate the mechanism of Trichel pulse discharge deflection in transverse airflow and give a further understanding of the dynamic process of the deflection through experiments and simulations. In experiments, we quantitatively record the deflection angle by processing the discharge images, and they show that a larger airflow speed will lead to a larger deflection angle. In simulations, the discharge deflection angle is calculated through a 2D fluid model. Besides, the periodic fluctuation of the deflection angle with Trichel pulses is revealed, and this phenomenon can be explained by the alternative dominant effect of airflow or ionization on the net production of positive ions in the vicinity of the tip. When the effect of airflow is dominant, more positive ions will generate away from the center of the tip, which will lead to an increase in the deflection angle. On the other hand, when the effect of ionization prevails, more positive ions will generate near the center because the electric field here is stronger, and the deflection angle will decrease. In addition, if these two effects balance, the deflection angle will reach its maximum or minimum value.