Numerical study of electrohydrodynamic atomization considering liquid wetting and corona discharge effects

Abstract

In this paper, the behavior of the cone-jet mode of fluid by electrohydrodynamic atomization (electrospray) is numerically simulated and investigated with the effect of liquid wetting and corona discharge effects. The simulation was performed with contact angle condition to fit the Taylor cone shape by experiments. Experimental data are provided to verify and validate the numerical method, followed by additional analyses on the effects of electrical conductivity, surface tension, flow rate, and fluid viscosity on the electrospray characteristics, including spray current and jet diameter. Numerical results by simulations are in reasonable agreement with experiments and consistent with the literature. Analyses on different contact angles suggest potentially major impacts of this factor on the cone-jet mode in high voltage and low flow rate circumstances. Furthermore, the influence of corona discharge on electrospray is also investigated by both electrospray–corona simulation and experiment using a high-speed camera, yielding a significant improvement in the numerical prediction for Taylor cone formation. Numerical results indicate that liquid wetting on capillary nozzles would be a vital factor for the Taylor cone formation in numerical electrospray–corona discharge studies.