A New Numerical Multiphase Flow Model of Water Droplets Dielectrophoretic-Induced Air Dehumidification

Abstract

Humidity control plays a vital role in maintaining healthy indoor environments and enhancing the performance of industrial processes. Conventional dehumidification systems, which predominantly rely on vapor compression cycles, are highly energy-intensive due to the requirement of cooling air well below its dew point. This research presents an alternative, energy-efficient approach to air dehumidification based on electric field-induced condensation. A comprehensive numerical investigation is conducted to analyze the interaction between humid airflow and electrically charged water droplets within a duct subjected to a high-gradient electric field, to assess the contribution of electrostatic forces—particularly dielectrophoretic effects—to enhanced vapor condensation. A hybrid Eulerian–Lagrangian framework is implemented on OpenFOAM® version 9. A dedicated electro-condensation model is developed to simulate the growth of electro-sprayed droplets, incorporating the Rayleigh charge limit and dielectrophoretic condensation dynamics. The electrospray process is represented as a cone-jet stabilized by surface tension, aerodynamic drag, electrostatic forces, and gravity. Experimental validation conducted in the author’s laboratory demonstrates strong agreement with simulation results. The numerical study is extended to evaluate downstream dehumidification performance using cyclone separators. The combination of electro-condensation with centrifugal separation is shown to improve condensate collection and flow regulation. In addition to the numerical analyses, an analytical model is formulated to investigate droplet growth under the influence of an electric field and the dielectrophoresis phenomenon. This research presents a novel and scalable methodology for electric field-assisted air dehumidification, contributing to the advancement of energy-efficient humidity control technologies for residential and industrial applications.