Multiphysics modeling of corona wind generation for electrohydrodynamic (EHD) drying of thin films

Abstract

Electrohydrodynamic (EHD) drying allows drying at lower temperatures and is thus more energy efficient, and provides better product quality. EHD drying utilizes an electric field to generate an airflow, which is then applied to dry moist materials. We present a multiphysics model to simulate corona wind generation during EHD drying of thin films. The simulations are used to (1) characterize corona wind generation in terms of air flow field and magnitude, (2) simulate the electric potential distribution with varying material permittivity, and (3) explore design improvements. A generic equation was developed in the form of a power-law correlation between Reynolds and EHD numbers: $\mathrm{Re}=a\mathrm{EH}{D}^b$. It allows straightforward design of EHD dryers since the Reynolds number can be used to estimate mass and heat transfer rates. This modeling study provides valuable insight into corona wind generation and can be used for further development of EHD dryer devices.