Universal behaviour in coalescence of polymeric droplets

ORAL

Abstract

One of the most common and frequent rheological phenomena observed in nature is the coalescence of droplets. It encompasses the importance of phenomena like raindrops formation in clouds, printing techniques, and even multiphase flows. The process of merging of two droplets towards forming a single daughter drop is known to exhibit formation of liquid bridge. The dynamics of bridge growth for fluids exhibiting characteristic relaxation time scales like polymer solutions is yet to be probed. In polymeric solutions the interplay between surface-forces along with the inertial, viscous, and elastic forces propel this phenomenon. By the balance of the pertinent forces in the phenomenon, we unveil a universal temporal evolution of the neck radius, R, as R/(νoλ)0.5 ~ (t/λ)0.36 Oh-0.36(c/c*)-0.432. Our findings are substantiated by a theoretical model using linear Phan-Thein-Tanner constitutive equation.

*Ministry of Education, Govt. of India; DST-SERB Grant no. EMR/2017/003025

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Publication: S. C. Varma, A. Saha, S. Mukherjee, A. Bandopadhyay, A. Kumar, and S. Chakraborty, "Universality in coalescence of polymeric fluids," Soft Matter (2020).

Presenters

  • Sarath Vegesina

    • Department of mechanical engineering, Indian Institute of Science

Authors

  • Sarath Vegesina

    • Department of mechanical engineering, Indian Institute of Science

  • Aniruddha Saha

    • Department of Mechanical Engineering, Indian Institute of Technology, Kharagpur, 721302, India
    • Department of mechanical engineering, Indian Institute of Technology Kharagpur

  • Siddhartha Mukherjee

    • Department of mechanical engineering, Indian Institute of Technology Kharagpur

  • Aditya Bandopadhyay

    • Department of mechanical engineering, Indian Institute of Technology Kharagpur

  • Aloke Kumar

    • Department of Mechanical Engineering, Indian Institute of Science, Bangalore, 560012, India
    • Department of Mechanical Engineering, Indian Institute of Science, India
    • Department of Mechanical Engineering, Indian Institute of Science, Bengaluru, India
    • Department of mechanical engineering, Indian Institute of Science

  • Suman Chakraborty

    • Department of mechanical engineering, Indian Institute of Technology Kharagpur