Numerical simulation of electrically deformed droplets less conductive than ambient fluid

Autor:	G.S.P. Castle, Kazimierz Adamiak, Osameh Ghazian
Rok vydání:	2013
Předmět:	Physics::Fluid Dynamics Physics Viscosity Colloid and Surface Chemistry Electric field Physics::Atomic and Molecular Clusters Newtonian fluid Dielectric Mechanics Electrohydrodynamics Deformation (meteorology) Breakup Capillary number
Zdroj:	Colloids and Surfaces A: Physicochemical and Engineering Aspects. 423:27-34
ISSN:	0927-7757
DOI:	10.1016/j.colsurfa.2013.01.048
Popis:	In this paper, the 3-D deformation of an initially uncharged and spherical droplet suspended in another immiscible fluid under dc uniform electric field is numerically investigated. Both the droplet and the ambient fluids are considered as incompressible Newtonian fluids. In all the cases both fluids are slightly conductive (``leaky'' dielectrics) with the ambient phase more conductive than the droplet. Three regimes were observed for droplet deformation: (1) oblate deformation (which can be predicted from the small perturbation theory), (2) oscillatory oblate-prolate deformation and (3) breakup of the droplet. It was found that an increased electric field causes the prolate deformation to be decreased in the oscillation regime. Further increase of the electric field leads to breakup, which creates a toroidal shape. It was shown that the threshold electric field strength depends on the viscosity ratio of both fluids. The critical electric capillary number beyond which the droplet eventually breaks up in a symmetric manner has been determined.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::0e1e3e34c29f0f297f1f103ebd103dee https://doi.org/10.1016/j.colsurfa.2013.01.048 Zobrazit plný text záznamu Full Text from ScienceDirect