| 초록 |
In this study, electrical charging phenomenon of a conducting droplet in dielectric fluid on the electrode surface has been studied. At the moment a conducting droplet touches the surface of the electrode, its free charge is discharged into the electrode and the droplet is charged with opposite charges, resulting repulsion due to Coulombic force. The droplet on opposite electrode also has the similar phenomenon. This process repeats itself. Accordingly, the electric charge on the droplet can be determined from the force balance between the Coulombic force and the drag force at the steady state. The effects of electric field, the bulk viscosity, and the droplet size in this phenomenon were investigated. The high speed CCD camera was used for observations of the velocity of the droplet. The drag force of a droplet is governed by Hadarmard-Rybczynski solution. It is shown that the more electrical charging occurs with larger drop size, higher electric field. It is also shown that the charge acquired from the electrode increases with the bulk viscosity when the viscosity is not very high. However, it is observed that this trend may be reversed in the case of very viscous bulk viscosity. |
