jp5b02975_si_001.zip (10.56 MB)
Mode Pattern of Internal Flow in a Water Droplet on a Vibrating Hydrophobic Surface
dataset
posted on 2015-06-04, 00:00 authored by Hun Kim, Hee-Chang LimThe
objective of this study is to understand the mode pattern of
the internal flow in a water droplet placed on a hydrophobic surface
that periodically and vertically vibrates. As a result, a water droplet
on a vibrating hydrophobic surface has a typical shape that depends
on each resonance mode, and, additionally, we observed a diversified
lobe size and internal flows in the water droplet. The size of each
lobe at the resonance frequency was relatively greater than that at
the neighboring frequencies, and the internal flow of the nth order mode was also observed in the flow visualization.
In general, large symmetrical flow streams were generated along the
vertical axis in each mode, with a large circulating movement from
the bottom to the top, and then to the triple contact line along the
droplet surface. In contrast, modes 2 and 4 generated a Y-shaped flow
pattern, in which the flow moved to the node point in the lower part
of the droplet, but modes 6 and 8 had similar patterns, with only
a little difference. In addition, as a result of the PIV measurement,
while the flow velocity of mode 4 was faster than that of model 2,
those of modes 6 and 8 were almost similar.