Title :
Experimental and computational studies of water drops falling through model oil with surfactant and subjected to an electric field
Author :
Ervik, Asmund ; Helleso, Svein Magne ; Munkejord, Svend Tollak ; Muller, Benjamin
Author_Institution :
Dept. of Energy & Process Eng., Norwegian Univ. of Sci. & Technol., Trondheim, Norway
fDate :
June 29 2014-July 3 2014
Abstract :
The behaviour of a single sub-millimetre-size water drop falling through a viscous oil while subjected to an electric field is of fundamental importance to industrial applications such as crude oil electrocoalescers. Detailed studies, both experimental and computational, have been performed previously, but an often challenging issue has been the characterization of the fluids. As numerous authors have noted, it is very difficult to have a perfectly clean water-oil system even for very pure model oils, and the presence of trace chemicals may significantly alter the interface behaviour. In this work, we consider a well-characterized water-oil system where controlled amounts of a surface active agent (Span 80) have been added to the oil. This addition dominates any trace contaminants in the oil, such that the interface behaviour can also be well-characterized. We present the results of experiments and corresponding two-phase-flow simulations of a falling water drop covered in surfactant and subjected to a monopolar square voltage pulse. The results are compared and good agreement is found for surfactant concentrations below the critical micelle concentration.
Keywords :
computational fluid dynamics; drops; electrohydrodynamics; oils; surfactants; two-phase flow; water; H2O; chemical tracing; computational studies; critical micelle concentration; crude oil electrocoalescers; electric field; industrial applications; monopolar square voltage pulse; surface active agent; surfactant concentrations; two-phase-flow simulations; viscous oil; water drop falling; water-oil system; Computational modeling; Electrodes; Equations; Gold; Manganese; Mathematical model; Video recording;
Conference_Titel :
Dielectric Liquids (ICDL), 2014 IEEE 18th International Conference on
Conference_Location :
Bled
DOI :
10.1109/ICDL.2014.6893172