Effects of relative humidity on contact electrification in granular system

Abstract

During grain transportation, particles become electrified through frequent contact with each other and surfaces, leading to charged particle agglomeration, which can threaten granular exploration. Humidity is a key factor influencing charge levels in granular systems, yet the mechanisms behind this effect, especially in size-distributed systems, are not well understood. This study presents numerical simulations based on the Mosaic charging model and experimental results to analyze humidity's impact on charging. Our findings indicate that relative humidity affects the charge magnitude but not its polarity, with peak charge occurring at relative humidity levels between 20 % and 40 %.