WATER DROPLET DEFORMATION AT ALTERNATING ELECTRIC FIELD ACTION: EXPERIMENT AND NUMERICAL SIMULATION

Abstract

The behavior of water droplets in liquid electrical insulation, specifically transformer oil, is essential in the context of electrical losses and strength. Experimental studies on water droplet deformation in an AC electric field have been previously conducted, and this paper expands on those experiments using various oils and advanced equipment with higher spatiotemporal resolution. In the paper, electrical recording of the acting voltage and optical recording of the behavior of droplets under its action are simultaneously carried out. Of the main results, the following can be noted: The drop periodically lengthens and shortens in the process of deformation, but even at the moments when the voltage passes through zero, it does not acquire a spherical shape. Additionally, there is a phase delay between deformation and voltage. Moreover, with increasing voltage, after a certain value, anomalous deformation of the droplets is observed. The given process was numerically simulated using Comsol Multiphysics. A two-dimensional axisymmetric model was used, and the equations of electrostatics and hydrodynamics were solved. The geometric deformation of the droplet was described using the arbitrary Lagrangian-Eulerian approach. The experiment and model showed excellent agreement, validating the study's outcomes.