| This paper seeks to analyze and interpret the demulsification mechanism of centrifugal field and pulsed electric field for W/O emulsion from a new viewpoint by establishing a mathematical model of inherent frequency for vibrations of drops of W/O emulsion based on the imposition of forces on such droplets in combination field, and also discusses the theoretical basis for existence of optimum frequency according to dynamics theory. In other words, the motion of single droplet of W/O emulsion in centrifugal field and pulsed electric field driven should be incorporated into a forced vibration of spherical or ellipsoidal droplet stimulated by periodic field forces, the emulsion droplets in such field will vibrate and deform due to the field forces alternating at certain frequency and centrifugal field, and has a certain orientated angle, the orientated angle not only decides the relationship of centrifugal field and pulsed electric field, but also influences inherent frequency of droplets; and a resonance will occur when the frequency of alternating field is equal to the inherent frequency of the droplets; at such frequency, the interfacial film will suffer with most serious damage, so it may be considered as the optimum frequency for demulsification. The inherent frequency relates to droplet size, interfacial tension, viscosity, temperature and density. Eliminating the impacts of some other factors (e.g. interfacial charge, emulsifier), the mathematical models of frequency via some interfacial tension related factors will be produced.By through oil-water emulsion's static experiment under combination of centrifugal fields and frequency-pulse electric, investigate peak frequency when demulsification efficiency of different diameter emulsion attains the maximal value, and compare the inherent frequency of relevant diameter droplets, will find the prediction results of the optimum frequency mathematical model agree well with the experimental results.
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