Frosting suppression via edge structure optimization: a comparative analysis of five geometric types

Frost accumulation at surface edges presents a significant challenge to thermal management systems; however, the quantitative impact of edge geometry on condensation frosting remains poorly understood. This study experimentally investigates the condensation and frosting behaviors of five edge geometries: right-angled, acute-angled, obtuse-angled, chamfered, and rounded edges. An edge-effect coefficient (α) is firstly introduced to quantify the influence of geometry on droplet growth dynamics. The results demonstrate that chamfered and rounded edges suppress edge-enhanced condensation by spatially redistributing vapor flux, reducing frost layer thickness on horizontal surfaces by 15.80% and 14.41%, respectively, compared to conventional right-angled edges. The underlying mechanism involves the creation of customized edge regions that compete for water vapor, effectively mitigating the vapor concentration gradient caused by geometric discontinuities. These findings provide fundamental insights into edge-affected phase change phenomena and offer a geometric strategy for passive frost suppression in heat pumps and refrigeration systems.