The variations of breakup and non-breakup regions for ferrofluid microdroplets in T-junctions with a proposed correlation

Document Type : Article

Authors

1 Center of Excellence in Energy Conversion (CEEC), Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran. P.O.B: 11155-9567

2 Energy Management Group, Energy and Environment Research Center, Niroo Research Institute, Tehran, Iran. P.O.B: 1466-5517

Abstract

Lots of attention has been paid to microfluidic and nanofluidic instruments in recent decades. One of the interesting instruments in this field that has attracted scientists is T-junctions. This paper reports an empirical study on the variation of breakup and non-breakup regions for ferrofluid microdroplets in symmetrical T-junctions under an asymmetrical magnetic field in the center of the junction. The asymmetrical magnetic field was generated using a permanent magnet on the right side of the T-junction. During the tests, ferrofluid microdroplets with different lengths and various velocities were entered into the T-junction and were influenced by an asymmetrical magnetic field. Results show that the increment in the magnetic flux density causes a higher possibility of non-breakup for ferrofluid microdroplets. Therefore, the breakup and non-breakup region in the diagram of non-dimensional length versus Ca number shifts upward. On the other hand, it was observed that the increment in Ca number is a key factor in breaking the microdroplets in the T-junction. Finally, a correlation was proposed to predict the breakup and non-breakup region due to different amounts of magnetic flux density and Ca number.

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Articles in Press, Accepted Manuscript
Available Online from 31 July 2024
  • Receive Date: 20 November 2020
  • Revise Date: 30 December 2023
  • Accept Date: 31 July 2024