Migration of a viscoelastic drop in a ratchet microchannel

Nema, Anant Kumar and Tripathi, Manoj Kumar and Sahu, Kirti Chandra (2022) Migration of a viscoelastic drop in a ratchet microchannel. Journal of Non-Newtonian Fluid Mechanics, 307. pp. 1-12. ISSN 0377-0257

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Abstract

We numerically investigate the deformation and migration of a viscoelastic droplet in a ratchet microchannel, a phenomenon that occurs in many practical applications and involves rich physics due to the associated complex geometry and non-Newtonian nature of the fluid. The numerical method required to handle viscoelastic fluid is also extremely challenging, especially when the Weissenberg number, a dimensionless relaxation time related to the viscoelastic fluids, is high. In the present study, we incorporate a log-conformation stabilization method that overcomes this numerical problem and examine the shape transition dynamics of a viscoelastic droplet for a wide range of parameters, including the wavelength and type of the ratchet, Weissenberg number, and Reynolds number. The droplet dynamics in a ratchet microchannel is compared to that in a straight channel. The presence of the ratchet section causes a distinct stress distribution in the viscoelastic droplet, which significantly influences the residence period, the shape of the droplet in the microchannel, and shape recovery dynamics when flowing out of the channel. © 2022 Elsevier B.V.

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IITH Creators:

IITH Creators	ORCiD
Sahu, Kirti Chandra	http://orcid.org/0000-0002-7357-1141

Item Type:

Article

Additional Information:

M. K. T. thanks the Department of Science and Technology, Government of India , for the financial support under the grant no. DST/INSPIRE/04/2015/000449 . K. C. S. thanks Science & Engineering Research Board, India for their financial support (Grant number: CRG/2020/000507 ).

Uncontrolled Keywords:

Droplet deformation; Log-conformation method; Numerical simulation; Ratchet microchannel; Viscoelastic fluid

Subjects:

Chemical Engineering

Divisions:

Department of Chemical Engineering

Depositing User:

. LibTrainee 2021

Date Deposited:

14 Oct 2022 11:43

Last Modified:

14 Oct 2022 11:43