69th Annual Meeting of the APS Division of Fluid Dynamics (November 20, 2016 — November 22, 2016)

V0042: Internal convection of an evaporating droplet of aqueous solution in the presence of two neighbouring droplets

Authors

• Tapan Kumar Pradhan, Department of Mechanical Engineering, Indian Institute of Technology Kanpur. Kanpur, UP-208016, India
• Pradipta Kumar Panigrahi, Department of Mechanical Engineering, Indian Institute of Technology Kanpur. Kanpur, UP-208016, India

DOI: https://doi.org/10.1103/APS.DFD.2016.GFM.V0042

Effect of neighbouring droplets on the internal convection of an evaporating droplet of aqueous NaCl solution is presented.  Confocal microscope is used to study the flow pattern. Evaporation from a droplet of aqueous solution induces natural convection inside the droplet. Evaporation from the droplet surface creates concentration gradient inside the droplet leading to buoyancy driven Rayleigh convection. A single droplet of aqueous solution shows symmetric flow pattern. In the presence of neighbouring droplets, the symmetric flow pattern becomes asymmetric. Neighbouring droplets significantly affect  the  evaporative flux distribution on the droplet surface . Hence, the flow pattern inside the droplet is influenced by the neighbouring droplets.