Theoretical scaling law for predicting evaporation rate from meniscus

•Measurement of evaporation rates of water in various gaps limited by diffusion.•Clarifying dependence of the quantities on perimeters and curvatures of menisci.•Deriving scaling law to relate evaporation rates to interface shapes of menisci.•Confirmation of maximum evaporation rates predicted by the scaling law. Previous studies have shown that diffusion-limited evaporation in the confined spaces such as tubes and gaps between parallel plates strongly depends on geometrical gap configurations. However, there is no study discussing the dependence of evaporation quantity on perimeter and curvature of the meniscus. In addition, there is no theoretical approach to predicting evaporation rates from menisci which have various interface shapes. In this study, evaporation rates in various geometrical gap configurations made of glass were experimentally measured and the dependence of evaporation quantity on perimeter and curvature of the meniscus was discussed. As the result, the different evaporation tendencies were found regarding the relation between capillary length and the characteristic length of gap configuration defined as an inner radius of a tube or a half of gap distance between parallel plates. Moreover, we derived the scaling law to relate evaporation rates to various interface shapes of menisci. The maximum evaporation rates predicted by this scaling law were consistent with the experimental data obtained in this study.