Particle migration in channel flow of an elastoviscoplastic fluid

Niazi Ardekani, Mehdi, 1990- (author): KTH,Teknisk mekanik,Linné Flow Center, FLOW

Tammisola, Outi, Associate professor (author): KTH,Linné Flow Center, FLOW,Teknisk mekanik

(creator_code:org_t)

Elsevier B.V. 2020
2020
English.
In: Journal of Non-Newtonian Fluid Mechanics. - : Elsevier B.V.. - 0377-0257 .- 1873-2631. ; 284

Related links:: https://doi.org/10.1...; show more...; https://doi.org/10.1...; https://urn.kb.se/re...; https://doi.org/10.1...; show less...

Abstract Subject headings

We study the dynamics of a neutrally buoyant rigid sphere carried by an elastoviscoplastic fluid in a pressure-driven channel flow numerically. The yielding to flow is marked by the yield stress which splits the flow into two main regions: the core unyielded region and two sheared yielded regions close to the walls. The particles which are initially in the plug region are observed to translate with the same velocity as the plug without any rotation/migration. Keeping the Reynolds number fixed, we study the effect of elasticity (Weissenberg number) and plasticity (Bingham number) of the fluid on the particle migration inside the sheared regions. In the viscoelastic limit, in the range of studied parameters (low elasticity), inertia is dominant and the particle finds its equilibrium position between the centreline and the wall. The same happens in the viscoplastic limit, yet the yield surface plays the role of centreline. However, the combination of elasticity and plasticity of the suspending fluid (elastoviscoplasticity) trigger particle-focusing: in the elastoviscoplastic flow, for a certain range of Weissenberg numbers (≈0.5), isolated particles migrate all the way to the centreline by entering into the core plug region. This behaviour suggests a particle-focusing process for inertial regimes which was not previously found in a viscoelastic or viscoplastic carrying fluid.

TEKNIK OCH TEKNOLOGIER -- Maskinteknik -- Strömningsmekanik och akustik (hsv//swe)
ENGINEERING AND TECHNOLOGY -- Mechanical Engineering -- Fluid Mechanics and Acoustics (hsv//eng)

By the author/editor: Chaparian, Emad; Niazi Ardekani, ...; Brandt, Luca; Tammisola, Outi, ...

About the subject

ENGINEERING AND TECHNOLOGY: ENGINEERING AND ...; and Mechanical Engin ...; and Fluid Mechanics ...

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