Role of droplet size variation on the effect of electric field for the separator coupling electric and swirling fields

•Investigating the role of droplet size variation in the influence of electric field on flow field.•Verifying a reduction of the viscosity of mixture due to the enlargement of droplet size on flow field.•Discussing the mechanism by which electric field affects the flow field. The utilization of a high-voltage electric field coupled with a swirl centrifugal field for separation is a promising technology. However, the precise mechanism by which the high-voltage electric field influences the flow field remains unclear. To address this, a numerical model was developed, integrating the governing equations, Population Balance Model, and Turbulence Model. The study analyzes the oil–water separation process under voltages and explore the impact of different initial particle sizes on the flow field. The numerical results reveal that the electric field amplifies the droplet size, thereby influencing the flow field. Additionally, the findings indicate that the electric field enhances the centrifugal force acting on the droplets by enlarging their size. This enhancement facilitates the migration of the droplets toward the wall. Consequently, the viscosity of the mixture decreases, resulting in reduced viscous drag on the liquid and ultimately leading to an increase in the velocity of the liquid.