2D Numerical Simulation of the Electrospraying Process of a Viscoelastic Liquid in an Ambient, Highly Viscous Liquid

The aim of this numerical work is to understand the electrospray process of a conducting, viscoelastic liquid inside an ambient dielectric, highly viscous liquid. We use the Oldroyd-B model (which is solved with the help of Log conformation approach) to capture the dynamics of the viscoelastic liquid. The interface between the viscoelastic liquid and the surrounding highly viscous liquid is captured using the volume-of-fluid (VoF) method. The bulk charge conservation equation is solved for the movement of free charge in the viscoelastic liquid under an electric field. The numerical results depict high-volume charge density at the tip of the initial interfacial profile which leads to the formation of a thin viscoelastic jet. This jet finally undergoes Rayleigh plateau instability due to which small droplets detach under the dripping mode. The electric charge remains trapped inside the droplets as these detach from the jet. Higher magnitude of the \(\tau_{p,xx}\) stress component appears on the jet interface near the orifice while such values for the \(\tau_{p,yy}\) component appear in the thin, stretched jet. This technique can be used to generate an emulsion of uniformly sized, charged droplets of a viscoelastic fluid inside an ambient viscous liquid.