posted on 2015-09-15, 00:00authored byViktor Grishaev, Carlo
Saverio Iorio, Frank Dubois, A. Amirfazli
The
aim of this work is to understand the changes in the observed
phenomena during particle-laden drop impact. The impact of millimeter-size
drops was investigated onto hydrophilic (glass) and hydrophobic (polycarbonate)
substrates. The drops were dispersions of water and spherical and
nearly iso-dense hydrophobic particles with diameters of 200 and 500
μm. The impact was studied by side and bottom view images in
the range 150 ≤ We ≤ 750 and 7100 ≤ Re ≤ 16400. The particles suppressed the appearance
of singular jetting and drop partial rebound but promoted splashing,
receding breakup, and rupture. The drops with 200 μm particles
spread in two phases: fast and slow, caused by inertial and capillary
forces, respectively. Also, the increase in volume fraction of 200
μm particle led to a linear decrease in the maximum spreading
factor caused by the inertia force on both hydrophilic and hydrophobic
substrates. The explanation of this reduction was argued to be the
result of energy dissipation through frictional losses between particles
and the substrate.