TY - JOUR
T1 - Impact Dynamics of Binary Off-Center Unequal-Sized Droplets Colliding on a Superhydrophobic Surface
AU - Li , Meixuan
AU - Wu , Jie
AU - Zhang , Tongwei
JO - Advances in Applied Mathematics and Mechanics
VL - 5
SP - 1223
EP - 1251
PY - 2024
DA - 2024/07
SN - 16
DO - http://doi.org/10.4208/aamm.OA-2023-0289
UR - https://global-sci.org/intro/article_detail/aamm/23292.html
KW - Droplet impact, droplet size, eccentric angle, superhydrophobic surface.
AB - <p style="text-align: justify;">We present a numerical study that investigates the collision between a falling
droplet and a sessile droplet on a superhydrophobic surface with various impact velocities, size ratios, and eccentric angles. After impact, the two droplets may merge
into a bigger droplet. We use the OpenFOAM volume of the fluid method to monitor
the droplet geometry, analyze the dynamic characteristics of the impact, determine the
contact time of the merged droplet on the surface, and locate the contact line of the
merged droplet. When a large droplet impacts a small droplet, increasing the eccentric angle decreases both the maximum spreading distance and the contact time for all
impact velocities. Additionally, it reduces the number of broken small droplets that
splash following fragmentation at high impact velocity. Droplets of equal size produce impacts that are nearly the same as those of a large droplet impacting a small
droplet. The only difference occurs at the moment of droplet fragmentation. When a
small droplet impacts a large droplet, increasing the eccentric angle by less than $10^{\circ}$ shortens the maximum spreading distance while only slightly increasing the contact
time. In addition, droplet fragmentation is significantly reduced. The results provide
insight into potential applications of droplet-solid interactions, which are valuable for
engineering applications such as anti-icing and self-cleaning.</p>