Morphology of drop impact on a superhydrophobic surface with macro-structures

Regulagadda, Kartik; Bakshi, Shamit; Das, Sarit K.

doi:10.1063/1.4997266

Cited by 56 publications

(24 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…21 Following this work, studies focused on contact time reduction by asymmetric dynamics have been carried out, including the inclined surface, 22,23 curved surface, [24][25][26][27][28][29][30] surfaces with macro structures of different geometries, [31][32][33][34][35][36][37][38][39][40] moving surfaces, 41,42 and off-center impact. 43,44 Besides the aforementioned asymmetric approaches, symmetric bouncing by involving the droplet center to retraction with point-like structure to reduce contact time has also been proposed. Liu et al fabricated convex surfaces with a height of 0.6 mm and a radius of 2.0 mm and found that such structures can reduce the contact time by 28.5%.…”

Section: Introductionmentioning

confidence: 99%

Dynamics of droplet impacting on a cone

Luo

Chu

et al. 2021

Physics of Fluids

View full text Add to dashboard Cite

Droplet rebound dynamics on superhydrophobic surfaces has attracted much attention due to its importance in numerous technical applications, such as anti-icing and fluid transportation. It has been demonstrated that changing the macro-structure of the superhydrophobic surface could result in significant change in droplet morphology and hydrodynamics. Here we conduct both experimental and numerical studies of droplet impacting on a cone, and identify three different dynamic phases by changing the impacting conditions, i.e., the Weber number and the cone angle. The spreading and retracting dynamics are studied for each phase. Particularly, it is found that in Phase 3, where the droplet leaves the surface as a ring, the contact time is reduced by 54% compared with that of a flat surface. A theoretical model based on energy analysis is developed to get the rebound point in Phase 3, which agrees well with the simulation result. Besides, the effect of Weber number and cone angle on the contact time is explored.Finally, the phase diagram of the three phases distribution with We and cone angle is given, which can provide guidance to related applications.

show abstract

Section: Introductionmentioning

confidence: 99%

Dynamics of droplet impacting on a cone

Luo

Chu

et al. 2021

Physics of Fluids

View full text Add to dashboard Cite

show abstract

“…Hydrophobic surfaces (HS) and superhydrophobic surfaces (SHS) possess some unique and practical properties such as surface cleaning, 17 anti-fouling, anti-icing, dropwise condensation 18 and drag reduction. 19 A superhydrophobic surface (SHS) is standardly defined as a surface with an equilibrium contact angle (CA) greater than 150˚ and very low (<10°) contact angle hysteresis (CAH). 20 The CAH, defined as the difference between the advancing and receding CA, is often used as a measure of drop mobility on a surface.…”

Section: Introductionmentioning

confidence: 99%

Maximum Spreading and Rebound of a Droplet Impacting onto a Spherical Surface at Low Weber Numbers

et al. 2018

View full text Add to dashboard Cite

The spreading and rebound patterns of low-viscous droplets upon impacting spherical solid surfaces are investigated numerically. The studied cases consider a droplet impinging onto hydrophobic and superhydrophobic surfaces with various parameters varied throughout the study, and their effects on the postimpingement behavior are discussed. These parameters include impact Weber number (through varying the surface tension and impingement velocity), the size ratio of the droplet to the solid surface, and the surface contact angle. According to the findings, the maximum spreading diameter increases with the impact velocity, with an increase of the sphere diameter, with a lower surface wettability, and with a lower surface tension. Typical outcomes of the impact include (1) complete rebound, (2) splash, and (3) a final deposition stage after a series of spreading and recoiling phases. Finally, a novel, practical model is proposed, which can reasonably predict the maximum deformation of low Reynolds number impact of droplets onto hydrophobic or superhydrophobic spherical solid surfaces.

show abstract

“…The stretch of the jet in the valley is dependent on the magnitude of the tangential momentum imparted to the drop. As w decreases, the spherical segment of the drop interacting with the inclined face increases producing higher tangential momentum (Regulagadda et al 2017). Secondary droplets are formed from the jet.…”

Section: Experimental Methodsmentioning

confidence: 99%

Triggering of flow asymmetry by anisotropic deflection of lamella during the impact of a drop onto superhydrophobic surfaces

2018

Self Cite

View full text Add to dashboard Cite

Water drop impacting a superhydrophobic surface (SHS) rebounds completely with remarkable elasticity. For such an impact, the balance between the inertial and capillary forces ascertain the contact time. This is found to be fairly constant for any macroscopically flat SHS and for a given drop volume. Recently, various studies have shown that breaking the radial symmetry during the drop impact can significantly reduce the contact time below that of a flat SHS. One such study has been performed on a cylindrical SHS with a curvature comparable to the drop. The reduction in contact time has been attributed to the radially anisotropic flow imparted by the tangential component of momentum and the elliptical footprint of the drop during the crash. Here, we perform drop impact experiments on bathtub-like SHS and show that the radial anisotropy can be triggered even in the absence of both the criteria mentioned above. This is shown to be a consequence of the lamella deflection during the spreading of the drop. The reduction in contact time is quite clearly evident in this experimental regime.

show abstract

Morphology of drop impact on a superhydrophobic surface with macro-structures

Cited by 56 publications

References 29 publications

Dynamics of droplet impacting on a cone

Dynamics of droplet impacting on a cone

Maximum Spreading and Rebound of a Droplet Impacting onto a Spherical Surface at Low Weber Numbers

Triggering of flow asymmetry by anisotropic deflection of lamella during the impact of a drop onto superhydrophobic surfaces

Contact Info

Product

Resources

About