An experimental study of condensation frosting characteristics on a rotating horizontal cold plate at different rotation speeds

Frosting is a prevalent issue across various industries, negatively impacting the functionality of equipment operating at low surface temperatures. Despite extensive research that has been conducted on frosting, investigations specifically addressing frosting progress on rotating surfaces remain limited. Therefore, this study aims to experimentally investigate the characteristics of condensation frosting on a horizontal cold plate at varying rotation speeds. The results reveal that an increase in rotation speed promotes frosting, as evidenced by the notably reduced duration of the droplet condensation and growth (DCG) stage, which decreases from 786 to 162 s as the rotation speed increases from 10 to 40 r/min. Accordingly, the rotation speed adversely affects the average droplet diameter at the end of the DCG stage, although the droplet growth rate increases with the rotation speed. Specifically, the average equivalent droplet diameter at the end of the DCG stage in the edge region varies from 181.1 to 230.9 μm, while in the inner region, it varies from 50.4 to 76.9 μm as the rotation speed decreases from 40 to 10 r/min. Notably, the frost layer surface roughness exhibits greater fluctuations at lower rotation speeds. The results of this study are anticipated to help the understanding, prediction, and mitigation of frosting on rotating surfaces.