The enhanced aerosol deposition by bipolar corona discharge arrays

The corona discharges provide an efficient way to induce precipitation or eliminate fog by increasing ion density in the open air. In this paper, one bipolar corona discharge array (positive and negative high voltage coupled simultaneously) which can generate high densities of positive and negative ions is developed. The comparison between bipolar corona discharge array and unipolar corona discharge array (positive or negative coupled only) indicates that bipolar corona discharge array can generate ~3 times higher ion density than unipolar corona discharge array. More charged aerosols are produced through collisions between ions and aerosols. The collision rate between aerosols is increased substantially by the attractive forces between positively and negatively charged aerosols. The deposition of aerosols induced by bipolar discharges is 25.7% higher than that of unipolar discharges at the humidity super-saturation condition. Therefore, the bipolar corona discharge system is a new option for the large scale ion sources used for artificial weather modification.