A hybrid approach for corona discharge in needle electrode configuration: in a large-scale space

Needle electrodes are widely used as the discharge electrode in charged particle-generating apparatus to study discharge characteristics due to their high efficiency. However, for the charged particle distribution of needle electrode corona discharge in a large-scale space (tens or even hundreds of centimeters), there is still a lack of an effective numerical simulation method. To solve this problem, a hybrid approach based on the combination of a hydrodynamic fluid model and an ion flow transport equation (ion drift model, based on the Kaptzov hypothesis) is put forward in this paper. The principle and implementation of the proposed method is introduced in detail. Further, the good consistency of the numerical simulation and a series of experiments under various applied voltages with two type sphere (radius 25 cm) apparatus, by comparing the charged particle density and discharge current, has demonstrated the accuracy and feasibility of the hybrid approach. This research provides an approach for the further study of corona discharge in a large-scale space, and implies the precise control potential in the application of low-temperature plasma, such as plasma material treatment, water treatments, gas disposal and so on. (paper)