Numerical Investigation on Isolated Moving Charged Droplet Evaporation in Electrostatic Field with Highly Volatile R134a

Abstract

Fundamental investigations of the charged droplet evaporation are helpful in enhancing the cooling capability and advancing the electrostatic spray model, whereas the corresponding data with the highly volatile R134a under electric field is very scarce. In this work, an improved evaporation model accounting for the effects of the corona wind, Coulombic fission and electric force under the electric field was developed and validated to evaluate the importance of the electric field on the moving charged R134a droplet evaporation for the first time. Results demonstrated that the electrostatic field can improve the charged droplet evaporation by means of the heat and mass transfer enhancement by the corona wind and counteracting the drag force from air. The droplet lifetime was shortened by 20.8% (from 105.6 ms to 83.6 ms) when the applied voltage increased from 0 kV to 10 kV. Exponential decay in the charged droplet lifetime when the applied voltage increased was observed.