Abstract:
A water drop impacting a superhydrophobic surface (SHS) rebounds completely with remarkable
elasticity. For a given drop size, the time of contact on a flat SHS remains constant. However, recent
studies show that the contact time can be reduced further by triggering an asymmetry in the hydrodynamics of impact. This can be achieved in different ways; an example being the impact on a cylindrical
SHS with a curvature comparable to the drop. Here, the anisotropic flow generated from the tangential momentum and elliptical footprint of the drop before the crash leads to the formation of lobes.
In the present work, we perform drop impact experiments on a bathtub-like SHS and show that the
radial anisotropy can be triggered even in the absence of both the tangential momentum and noncircular footprint. This is shown to be a consequence of lamella deflection during the drop spreading.
The reduction in contact time is quite clearly evident in this experimental regime. Published by AIP
Publishing.
