Particle migration in channel flow of an elastoviscoplastic fluid

Sökning: L773:0377 0257 > Particle migration ...

QC 20200929
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
Elastoviscoplastic fluid
Particle migration
Viscoelastic fluid
Yield-stress fluid
Channel flow
Elasticity
Non Newtonian flow
Plasticity
Reynolds number
Viscoelasticity
Yield stress
Buoyant rigid sphere
Elasto-viscoplastic
Elasto-viscoplasticity
Equilibrium positions
Inertial regimes
Trigger particles
Weissenberg number
Wall flow

Niazi Ardekani, Mehdi,1990-KTH,Teknisk mekanik,Linné Flow Center, FLOW(Swepub:kth)u14fhowv (författare)
Brandt, LucaKTH,Linné Flow Center, FLOW,Teknisk mekanik(Swepub:kth)u15iawoo (författare)
Tammisola, Outi,Associate professorKTH,Linné Flow Center, FLOW,Teknisk mekanik(Swepub:kth)u11gdc9f (författare)
KTHLinné Flow Center, FLOW (creator_code:org_t)

Ingår i:Journal of Non-Newtonian Fluid Mechanics: Elsevier B.V.2840377-02571873-2631

Av författaren/redakt...: Chaparian, Emad; Niazi Ardekani, ...; Brandt, Luca; Tammisola, Outi, ...

Om ämnet

TEKNIK OCH TEKNOLOGIER: TEKNIK OCH TEKNO ...; och Maskinteknik; och Strömningsmekani ...

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.