Dynamics of ferro fluid droplet impact on hydrophobic mesh surface

Abstract

Droplet impact has been of interest in various fields extending from environmental science to engineering fields and understanding droplet behavior becomes critical in exploring processes like erosion, painting, oil–water separation, and heat transfer. Droplet impact behaviour can be altered by external influences such as ultrasonic excitations, magnetic fields, thermal radiation, and similar. In the present study, impact dynamics of water-ferro particles mixed droplet over hydrophobic mesh surfaces under magnetic influence are investigated and dynamic characteristics are assessed for various ferro-particles concentrations and mesh sizes. Droplet restitution, rebound, implement, and newborn droplet properties are analysed and explored experimentally. It is demonstrated that Weber number, mesh size and ferro particle concentration in droplet fluid have significant effect on the droplet behaviour over hydrophobic mesh. Increasing Weber number (We > 12) lowers the restitution coefficient, which becomes notable for large mesh aspect ratios. Droplet contact duration on mesh surface reduces with increasing Weber number while it reduces with ferro-particle concentrations. Volume of droplet fluid penetration enhances with ferro particle concentration and Weber number. Similarly, number of fragments of penetrated fluid increases with particle concentration and Weber number demonstrating the strong magnetic influence on the mechanism of droplet fluid fragmentation.