| The Leaky Dielectric Model (LDM), was extended to large droplet distortions (Extended LDM, ELDM). The droplet deformation and breakup of pairs of several fluids was studied experimentally. Comparison of the experimental results, and previously published data with the predictions of the LDM and ELDM showed: (1) Deformation parallel to the field direction: The LDM did not predict the qualitative trend of the data. The ELDM not only predicted the data qualitatively but for 9 out of 13 systems studied, it also predicted the data quantitatively when the experimental uncertainties in its input parameters were taken into account. For the remaining 4 systems, the ELDM could be reconciled with the experimental data by considering the possible change of the interfacial tension with the electric field. (2) Deformation perpendicular to the field direction: For one out of 4 systems studied the ELDM agreed quantitatively with the experimental data. For the other 3 systems the ELDM overestimated the observed aspect ratios. For those systems, either the viscosity of the matrix was much smaller than that of the droplet (a limitation of the ELDM) or the value of total charge relaxation time was relatively large (a conflict with one of the assumptions of the ELDM).; In high electric fields, the ELDM predicts either continuous droplet deformation or deformation hysteresis depending on the ratio of the droplet and matrix conductivities, permittivities and viscosities. For droplets deforming parallel to an electric field, if the droplet conductivity is at least 21.7 times larger than that of the matrix, only deformation hysteresis should occur. For droplets deforming perpendicular to the electric field, if the matrix conductivity is at least 1.67 times larger than that of the droplet, only continuous deformation should occur. |
