Pulsation characteristics of corona discharge in electrohydrodynamic process using ionic liquid

In this study, the pulse phenomenon is found in the electrohydrodynamic (EHD) process using an ionic liquid, which is similar to other liquids, but there are significant differences in pulse characteristics. The frequency, waveform, charge, and images of the pulse in the EHD process with the ionic liquid are studied experimentally. The results show that the pulse process is divided into two stages: a low-frequency pulse stage and a high-frequency pulse stage. We propose that the pulse is caused by the air corona discharge and the frequency is influenced by the anchoring radius of liquid oscillation in the electric field. The different anchoring radii of the two stages are the main reason for the obvious difference in the frequency. The main difference between the ionic liquid and other solutions is the conductivity and the surface tension coefficient, which is the cause of corona discharge rather than electrospray.