Experimental Investigation of the Effects of Superhydrophobic Surfaces on Anti-Icing at Different Air Velocities and Humidity Conditions

Abstract

This study experimentally investigated the anti-icing performance of superhydrophobic coatings under varying flow and humidity conditions. Aluminum tubes cooled by refrigerant circulation were subjected to airflow at relative humidity levels of 45 %, 65 %, and 75 %, and Reynolds numbers between 5000 and 15000. Hydrophobic aluminum base and three types of coatings were tested: Ultra Ever Dry (UED), and UED enhanced with 0.50 wt% graphene (UEDG50) and 0.50 wt % hemp powder (UEDKT50). Results: showed that UEDKT50 exhibited the lowest icing temperature at-5.70 degrees C under 45 % humidity and 5000 Reynolds number, representing approximately 349 % greater icing resistance than the aluminum base. This surface also had the highest roughness value (6.33 mu m), about 8.5 times greater than the base surface, enhancing Cassie-Baxter air pocket formation and reducing ice adhesion. Friction tests revealed that UEDKT50 had the lowest friction coefficient (1.13), compared to UEDG50 (1.15) and UED (1.22), indicating better surface adhesion and wear resistance. Overall, the findings demonstrate that superhydrophobic surfaces significantly improve icing resistance, and this enhancement is strongly influenced by surface roughness and mechanical stability.