液滴撞击超疏水单狭缝表面的实验研究OA

Existing studies of droplet impact dynamics on superhydrophobic surfaces have predominantly focused on conventional substrates lacking macroscopic geometric features,while comparatively limited attention has been given to non-conventional surfaces with macro-structures that are common in practical engineering.In this study,we experimentally investigate the impact dynamics of droplets on superhydrophobic surfaces featuring a single macroscopic slot.We systematically examine the effects of the dimensionless slot width(the ratio of the actual slot width to the initial droplet diameter,0.09-0.54)and the Weber number(4.03-36.59)on droplet spreading,retraction,penetration,and fragmentation.Four characteristic regimes are observed—complete rebound,rebound with partial penetration,fragmentation with partial penetration,and full penetration—and their corresponding parameter maps are constructed.The maximum spreading diameter decreases progressively as the slot width increases.By accounting for both the slot width and liquid penetration height,a modified theoretical model is developed to predict the maximum spreading coefficient as a function of the Weber number,achieving great agreement with experimental measurements.Moreover,partial liquid penetration during impact reduces the effective mass involved in spreading and retraction,leading to a significant reduction in the droplet-surface contact time.