jz0c00788_si_001.pdf (289.12 kB)
Contact Time of a Bouncing Nanodroplet
journal contribution
posted on 2020-03-25, 18:46 authored by Fang-Fang Xie, Shu-Hang Lv, Yan-Ru Yang, Xiao-Dong WangWe
study the bouncing dynamics of nanodroplets on superhydrophobic
surfaces. We show that there are three velocity regimes with different
scaling laws of the contact time, τ. Although τ remains
constant over a wide velocity range, as seen for macroscale bouncing,
we demonstrate that viscosity plays an essential role in nanodroplet
bouncing even for low-viscosity fluids. We propose a new scaling τ
∼ (ρμR04/γ2)1/3 = (R0/v0)We2/3Re–1/3 to characterize the viscosity
effect, which agrees well with the simulated results for water and
argon nanodroplets with various radii and hydrophobicities. We also
find pancake bouncing of nanodroplets, which is responsible for an
abruptly reduced τ in a high-velocity regime.