Droplet shedding characteristics on metal fibers with different wettability and inclined angles

Abstract

Critical size of droplet on metal fiber is an important parameter during the dehumidifying process, as it determines the drainage performance of metal foam heat exchangers. In the present study, the droplet shedding characteristics on metal fibers with various fiber diameters, surface wettability and inclined angles were investigated experimentally. The results show that, the critical size of droplet on metal fibers is increased by 69%-213% as the receding contact angle reduces from 132.8° to 17.2°, and it is increased by 93%-292% as the fiber diameter increases from 0.3 mm to 2.0 mm. As the inclined angle of metal fiber increases from 0° to 90°, the critical droplet size is decreased by 78%-86%. Based on the equilibrium of gravity and capillary force, a predictive correlation for the critical droplet size on metal fibers with different wettability and inclined angles was developed, and it agrees with 90% of the experimental data within a deviation of ±15%.