Revealing the primary role of airflow structure in electrohydrodynamic drying

Abstract

This study investigates the relative contributions of airflow structure and electrical effects in electrohydrodynamic (EHD) drying by comparing electrically and mechanically generated impinging jet flows. Both flows exhibited comparable velocity profiles, surface temperature distributions, and drying performance. The contribution of electrical effects was assessed by shielding the electric field, while maintaining comparable airflow conditions at the sample surface. The results indicate that the similar drying performance of EHD and jet flow is mainly attributed to their comparable airflow characteristics, while the direct contribution of electrical effects is limited under the investigated conditions. A comparison between non-uniform impinging jet flow and uniform channel flow further confirmed the critical role of flow non-uniformity in enhancing convective mass transfer. Finally, electrically driven impinging jet flow consumed less energy than mechanical jet flow, demonstrating potential of EHD as an energy-efficient drying technology.