Influencing Factors of Flow Field of Ionic Wind Induced by Corona Discharge in a Multi-Needle-to-Net Electrode Structure Under Direct-Current Voltage

Fangcheng Lv,Ping Wang,Jianghai Geng,Haoou Ruan,Jingxuan Song

doi:10.1109/access.2019.2938420

Fangcheng Lv, Ping Wang + Show 3 more

Open Access

https://doi.org/10.1109/access.2019.2938420

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Abstract

The morphologies and velocity of ionic wind induced by direct-current (DC) corona discharge were experimentally measured. DC voltage was applied to short air gaps of high-voltage electrode-needle electrode and grounding electrode-net electrode to generate coronas, so as to allow the generation of ionic wind induced by corona discharge. The purpose of the study is to optimise the multi-needle-to-net electrode structure to improve the velocity of the ionic wind and keep it in a relatively stable state. For this purpose, the influences of various parameters on the velocity of the ionic wind were explored. The research results showed that the side length of meshes and the distribution mode of needles significantly affected the velocity of the ionic wind. The maximum velocity of the ionic wind, when the side length of meshes was 0.85 mm was 3 and 1.28 times those when the side lengths of the meshes were 2 and 0.425 mm, respectively. This indicated that there was an optimal side length that can maximise the velocity of the ionic wind. Increasing the number of needles and optimising the distribution mode of needles can effectively improve the velocity, that is, the improvement of the number and distribution uniformity of needles was conducive to increase the velocity of the ionic wind. Increasing the voltage amplitude can increase the velocity of the ionic wind, however, it was possible that noise was significant and in this case, the corresponding voltage cannot be considered as the working voltage of the ionic wind generator.

Highlights

Ionic wind induced by corona discharge is generated according to the following process: in a stable high-voltage electric field, while applying a high voltage between two electrodes with greatly different curvatures, air near the electrode with the larger curvature is ionised to generate an electron avalanche if the applied voltage reaches the corona inception voltage; the electrons and positive ions move to two opposite electrodes under the effect of the electric field force so as to drive the motion of air molecules, forming the ionic wind [1]–[4]
In 1986, Sigmond proposed a theoretical model for the voltage and current of a needle-to-plate corona discharge system, which provides a theoretical basis for subsequent research on the ionic wind [8]
We studied the motion of the positive and negative ions and the ionic wind movement trend under positive voltage

Summary

INTRODUCTION

Ionic wind induced by corona discharge is generated according to the following process: in a stable high-voltage electric field, while applying a high voltage between two electrodes with greatly different curvatures, air near the electrode with the larger curvature is ionised to generate an electron avalanche if the applied voltage reaches the corona inception voltage; the electrons and positive ions move to two opposite electrodes under the effect of the electric field force so as to drive the motion of air molecules, forming the ionic wind [1]–[4]. Moreau and Touchard [12] and Huang [13] found that the positive DC power supply was more suitable for the ionic wind system, and analyzed the voltage polarity and gap spacing, and discovered that in the same case, the velocity and efficiency of ionic wind generated by the needle-net structure were higher than that of the needle-ring structure. On this basis, the optimized arrangement of mesh size and electrode spacing could obtain the optimal solution of the experiment. The results were expected to provide a basis for optimisation and design of the ionic wind generator in industrial production

GENERATION OF THE IONIC WIND

MOVEMENT OF IONS UNDER POSITIVE DC VOLTAGE

CONCLUSION