2025/04/24 by Diptendu Sen, Mohammadhossein Firouznia, Sen, Diptendu +5
Engineering · #Aerosol Filtration and Electrostatic Precipitation #Electrohydrodynamics and Fluid Dynamics #FOS: Physical sciences #Fluid Dynamics (physics.flu-dyn) #Power Transformer Diagnostics and Insulation
paper · pdf · doi:10.48550/arxiv.2504.17257
openalex publication_date 2025/04/24 · openalex created_date 2025/10/18 · openalex updated_date 2026/07/28
An isolated charge-neutral drop suspended in an unbounded medium does not migrate in a uniform DC electric field. A nearby wall breaks the symmetry and causes the drop to drift towards or away from the boundary, depending on the electric properties of the fluids and the wall. In the case of an electrically insulating wall and an electric field applied tangentially to the wall, the interaction of the drop with its electrostatic image gives rise to repulsion by the wall. However, the electrohydrodynamic flow causes either repulsion for a drop with R/P<1, where R and P are the drop-to-medium ratios of conductivity and permittivity, respectively, or attraction for R/P>1. We experimentally measure droplet trajectories and quantify the wall-induced electrohydrodynamic lift in the case R/P<1. Numerical simulations using the boundary integral method agree well with the experiment and also explore the R/P>1 case. The results show that the lateral migration of a drop in a uniform electric field applied parallel to an insulating wall is dominated by the long-range flow due to the image stresslet.