Numerical Simulation of Charged Droplets Dynamics in an Electrohydrodynamic Spraying with Primary Break-up

The size and the axial/radial velocity distributions of electrically controlled droplets generated from Taylor cone operating in the stable cone-jet regime are simulated by numerical modeling of electrosprays. To achieve these goals, a numerical code in FORTRAN is developed. Electrospray droplet dynamics considered the diluted two-phase flow and used Lagrangian method for tracking of a single drop and in the simulation the effect of still air around drops is taking to account in one direction. Also, a new model is used to determine the primary breakup process of jet to calculate the initial droplet diameter and breakup space. A model is formulated as function of liquid flow rate, needle-to-counter electrode distance, applied voltage, and electrical conductivity and surface tension of the liquid in a DC electric field is presented with a 2D electrohydrodynamic model. The droplet size reduction can be explained by evaporation and/or Coulomb explosion. Results show that moving downstream, the average velocity of droplets decreases monotonically. This paper reports a numerical study of the effects of an externally applied electric field on the dynamics of drop formation from a vertical metal capillary. The fluid issuing out of the capillary is a viscous liquid, the surrounding ambient fluid is air, and the electric field is generated by establishing a potential difference between the capillary and a horizontal, electrode placed downstream of the capillary outlet. The Primary jet Break-up and droplet transport and evaporation of electrohydrodynamic sprays is investigated by modeling of droplet size and velocity distribution in spray cones and a series of drop migrations under the influence of an electric field were carried out and the results are in good agreement with other theoretical and experimental studies.