Title :
Behavior of water droplets on insulator surfaces submitted to DC voltage-coalescence
Author :
Ndoumbe, J. ; Beroual, A. ; Imano, A. Moukengue
Author_Institution :
AMPERE Lab., Ecole Centrale de Lyon, Ecully, France
Abstract :
This paper aims at studying the behavior of water drops deposited on dielectric composite insulating surfaces under DC voltage stress. Experiments were conducted on the coalescence of pairs of sessile water droplets. It particularly analyzes their behavior depending on their size, conductivity and location with respect to electrodes as well as the hydrophobicity of insulator. The conditions for coalescence as well as the discharges activities were also investigated. The critical electric fields corresponding to the instability of water droplets were also determined. The results obtained show that the coalescence rate depends mainly on three parameters: the droplets location on the insulating surface, the droplets volume and the distance between droplets. Drop-drop coalescence produces larger drop which are more sensitive to electric field. Large drop easily deforms, enabling electric current to flow between both electrodes. The magnitude of the current during the coalescence process increases while droplets are approaching together.
Keywords :
dielectric materials; hydrophobicity; insulators; DC voltage stress; DC voltage-coalescence; coalescence process; coalescence rate; critical electric fields; current magnitude; dielectric composite insulating surfaces; discharges activities; drop-drop coalescence; droplet location; droplet volume; electric current; electric field; insulating surface; insulator hydrophobicity; insulator surfaces; sessile water droplets; water droplet behavior; water droplet instability; Conductivity; Electric fields; Electrodes; Insulators; Liquids; Surface treatment; Voltage measurement; DC electric field; droplet elongation; insulation materials; water droplet coalescence;
Conference_Titel :
Electrical Insulation and Dielectric Phenomena (CEIDP), 2012 Annual Report Conference on
Conference_Location :
Montreal, QC
Print_ISBN :
978-1-4673-1253-0
Electronic_ISBN :
0084-9162
DOI :
10.1109/CEIDP.2012.6378883