Oct 2022
Zoom link: https://kaust.zoom.us/j/93470060850
ID: 93470060850
The shape of a droplet at impact onto a liquid pool may greatly influence the dynamics of the cavity formation and splashing. Although droplet impact onto a liquid pool has been investigated for relatively small droplets, behaviors greatly change when the droplet is large enough that significant oscillation, deformation occurs. We experimentally investigate large droplet impact (1 to 6 cm dia.) onto a deep pool of water. Droplet release height is selected to cover a larger range of Weber numbers from 102 to 105. The droplets oscillate significantly when diameters are larger than the capillary length. The shape and dynamics of the cavity formed by the large droplets are significantly affected by the deformation of the droplet at impact. In general, three different shapes of the impacting droplets occur: prolate, oblate and circular. We show that, for a fixed liquid volume and a fixed Weber number of an impacting droplet, prolate shaped droplets produce the maximum cavity depth whereas an oblate shaped droplet results in a minimum cavity depth. The ratio of cavity width to maximum cavity depth (cavity aspect ratio) is a function of the horizontal diameter of the droplet at impact. For extremely large droplets the increased horizontal diameter results in a reduced impact energy flux leading to reduced cavity depth.
Sandip is a postdoctoral fellow at Splash Lab in the mechanical engineering department at KAUST since January 2022, working with Prof. Tadd T. Truscott. In 2021, he obtained his PhD from the department of aerospace engineering, Indian Institute of Technology Bombay (IIT Bombay). His research interests are in the domain of aerospace propulsion, fluid dynamics, liquid atomization, sprays and spray-acoustic interaction.