ECCOMAS 2024

Numerical study of the water drop behavior in a vertical electric field

  • Martynenko, Alex (Dalhousie University)
  • Naderi, Pejman (Dalhousie University)

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The effect of electric fields on the motion, deformation, and disintegration of water droplets has been studied for a long time. Scientists have been particularly interested in improving processes related to droplet behavior in electric fields, driven by the progress in industrial applications like electrowetting, electrospraying, and electrocoalescence [1]. Despite recent experimental and numerical investigations, droplet behavior in electric fields remains inadequately understood. Our study will focus on droplet behavior in vertical electric fields, shedding light on motion, deformation, and disintegration in uniform and non-uniform fields. Our analysis uses COMSOL simulation software to investigate single water droplet behavior in a vertical electric field within an air environment. We examine variables such as electric field intensity, droplet diameter, and area uniformity while considering gravity. Figure 1 illustrates the chosen configurations. Figure 1 Electric field lines. (a) uniform field, (b) non-uniform field, (c) close to the droplet. Droplet motion in a uniform electric field depends on factors like fluid viscosity, gravity, and electrostatic forces. In a non-uniform electric field, a dielectrophoretic force is additionally at play, guiding droplets toward higher electric field regions [2]. Moreover, a high-intensity electric field can ionize water molecules, causing them to scatter as ionized particles. This process, akin to water evaporation, arises from non-thermal scattering driven by electrostatic repulsion among unipolar charges.