This study experimentally investigates the influence of surface wettability on the frosting characteristics of three types of corrugated structures (Types A, B, and C) under controlled low-temperature conditions. The experiments were conducted in a constant-temperature bath at a cold surface temperature of –5°C, relative humidity of 90%, and ambient air temperature of 10°C. The results reveal that the variation trends of frost morphology, frost mass, and frost layer thickness are generally consistent across surfaces with different wettability. Among the tested surfaces, frost crystal formation and complete surface coverage occurred latest on the superhydrophobic surface (CA = 153.9–165.8°), next on the bare aluminum surface (75.3–83.2°), and earliest on the hydrophilic surface (5.3–7.5°). At the same frosting duration, the superhydrophobic surface exhibited a sparse and fluffy frost layer, the bare aluminum surface formed a rough and dense frost, while the hydrophilic surface developed a fine and compact frost layer. The amount of frost formation decreased in the order of hydrophilic > bare aluminum > superhydrophobic, indicating that the superhydrophobic surface provides the most significant anti-frosting effect during the initial stages of frost formation. For instance, on the Type A corrugated structure, after 15 min of frosting, the frost mass on the superhydrophobic surface was 38.78% and 68.45% lower than those on the bare aluminum and hydrophilic surfaces, respectively. After 30 min, these differences were 4.99% and 25.26%, respectively. Overall, the superhydrophobic surface exhibited the smallest frost mass and frost layer thickness, demonstrating superior anti-frosting performance compared with the other surface types.

Superhydrophobic surfaces, a new type of green material, exhibit promising application prospects in the field of anti-/de-icing. In this paper, the kinetic behavior of impinging droplets on surfaces with different temperatures (-25-16 ℃), different inclination angles (0°-60°), and different wettability (hydrophilic and superhydrophobic surfaces) is investigated through experimental comparisons. The variations of the droplet morphology, spreading factor, spreading time, and contact time are analyzed. The results show that the impinging droplets exhibit different kinetic behaviors after spreading due to the different inclination angles and wettability. The maximum spreading factor and spreading time on hydrophilic surfaces increase with the inclination angle. The variation of the spreading time on superhydrophobic surfaces follows the same trend as that on hydrophilic surfaces, while the maximum spreading factor decreases with an increase in the inclination angle, especially at T_s>-25 ℃; Compared to hydrophilic surfaces, the impinging droplets have shorter spreading times on superhydrophobic surfaces, which can reach about 10 times at T_s=-25 ℃. Increasing the wall inclination angle breaks the symmetric bounce of the droplets on the horizontal superhydrophobic surface, thereby shortening the contact time of the droplets. This suggests that increasing the inclination angle can effectively inhibit the freezing of water droplets.