Numerical investigation of non-uniform frost formation mechanisms on cold circular surfaces

Abstract

Frost on curved surfaces impairs equipment operation. This study presents an enhanced model to better understand frost formation mechanisms on low-temperature curved surfaces. The model incorporates local flow characteristics of wet air and frost formation dynamics to more accurately simulate frost evolution on low-temperature curved surfaces, such as circular surfaces. Compared with existing studies, this work emphasizes local data validation, demonstrating higher accuracy and reliability in predicting localized frost formation. Model validation results show good agreement between numerical calculations and experimental data, with average errors in frost thickness and density within 6.0% and 8.1%, respectively. Analysis reveals that frost formation non-uniformity is primarily influenced by the coupling of wet air flow characteristics and internal heat transfer in the frost layer. On the windward side, frost grows rapidly due to direct airflow impact, leading to higher local thickness and density. In contrast, the leeward side is significantly influenced by vortex effects, where airflow velocity variations directly affect frost distribution and growth patterns. This non-uniformity becomes more pronounced at low-velocity conditions. Additionally, heat transfer in the frost layer is primarily governed by conduction, though convective heat exchange near the surface also plays a significant role. Heat transfer characteristics not only affect frost temperature distribution but also regulate its growth rate and structural evolution. This study explores the coupled heat and mass transfer mechanisms in frost formation, offering theoretical support for more accurate frost evolution predictions.