67th Annual Meeting of the APS Division of Fluid Dynamics (November 23, 2014 — November 25, 2014)

V0042: Radial jetting during the impact of compound drops

Authors

• Jia Ming Zhang, Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
• Er Qiang Li, Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
• Sigurdur T. Thoroddsen, Division of Physical Sciences and Engineering and Clean Combustion Research Centre, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia

DOI: https://doi.org/10.1103/APS.DFD.2014.GFM.V0042

Here we report radial jetting behavior during the impact of compound droplet onto a dry solid surface. The size and number of the inner droplets was precisely controlled by a microfluidic device. With the help of high-speed video imaging from both side view and bottom view, intricate and regular horizontal jetting patterns were recorded.  The radial jets are formed due to the interaction between the inner droplets and the outer liquid film, and the jet velocity is much higher than the drop impact velocity. The number of inner droplets and their position within the outer droplet were shown to be very important parameters which governed the generation and pattern of the jets. Other parameters such as droplet impact velocity, inner/outer liquid viscosity, density and interfacial tension have also been varied and used to analyze the jetting dynamics.