A multi-scale description of orientation in simple shear flows of confined rod suspensions

Pérez, Marta Gil; Scheuer, Adrien; Abisset-Chavanne, Emmanuelle; Chinesta, Francisco; Keunings, Roland

doi:10.1016/j.jnnfm.2016.01.011

Cited by 27 publications

(12 citation statements)

References 31 publications

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“…5, bottom). In other words, and as concluded in our previous work [Perez, Scheuer, Abisset-Chavanne et al (2016); Scheuer, Abisset-Chavanne, ], the main challenge with traditional macroscopic models involving moments of the orientation pdf lies more with representation capabilities in highly confined conditions than with a suitable description of the induced orientation kinematics. On the other hand, the data-driven approach reproduces quite well the predictions provided by the expensive microscopic simulations.…”

Section: Data-driven Simulationmentioning

confidence: 91%

“…The gap walls now prevent the particle from rotating freely and some trajectory, passing outside the flow domain are thus forbidden. We have shown in previous work [Perez, Scheuer, Abisset-Chavanne et al (2016); Scheuer, Abisset-Chavanne, ] that in that case, the fibre kinematics can be written as Jeffery's equation augmented with an additional term that prevents the fibre from leaving the flow domain, p =ṗ J +ṗ C ,…”

Section: Confined Dilute Suspensions Of Rods Immersed In a Simple Shementioning

confidence: 99%

“…These kinematics, derived under the assumptions of a Stokes flow, lay the foundation for nearly all models used today. Extending Jeffery's theory to account for various internal or external effects, including Brownian effects [Chinesta (2013)], bending phenomena [Abisset-Chavanne, Férec, Ausias et al (2015)], particle inertia [Scheuer, Grégoire, Abisset-Chavanne et al (2018)], electrical forces [Perez, Abisset-Chavanne, Barinsiski et al (2015)], wall effects [Perez, Scheuer, Abisset-Chavanne et al (2016); Scheuer, Abisset-Chavanne, ] is readily achievable using a dumbbell representation of a rod [Bird, Curtiss, Armstrong et al (1987); Binetruy, Chinesta and Keunings (2015)]. Despite the richness of the possible descriptions at the microscopic scale, the computational effort to efficiently track millions of particles (as in scenarios of industrial interest) is in general unaffordable.…”

Section: Introductionmentioning

confidence: 99%

“…In Section 3, this methodology is first illustrated in the well-known case of dilute fibre suspensions, where it can be compared against macroscopic closurebased models. Its relevance is then shown in the case of confined fibre suspensions, for which closures proved to be inadequate [Perez, Scheuer, Abisset-Chavanne et al (2016); Scheuer, Abisset-Chavanne, ]. Finally, we apply this framework in a more complex case involving semi-concentrated suspensions of electrically-charged rods, for which no reliable macroscopic model is available.…”

Section: Introductionmentioning

confidence: 99%

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Data-Driven Upscaling of Orientation Kinematics in Suspensions of Rigid Fibres

Scheuer¹,

Ammar²,

Abisset-Chavanne³

et al. 2018

CMES

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Describing the orientation state of the particles is often critical in fibre suspension applications. Macroscopic descriptors, the so-called second-order orientation tensor (or moment) leading the way, are often preferred due to their low computational cost. Closure problems however arise when evolution equations for the moments are derived from the orientation distribution functions and the impact of the chosen closure is often unpredictable. In this work, our aim is to provide macroscopic simulations of orientation that are cheap, accurate and closure-free. To this end, we propose an innovative data-based approach to the upscaling of orientation kinematics in the context of fibre suspensions. Since the physics at the microscopic scale can be modelled reasonably enough, the idea is to conduct accurate offline direct numerical simulations at that scale and to extract the corresponding macroscopic descriptors in order to build a database of scenarios. During the online stage, the macroscopic descriptors can then be updated quickly by combining adequately the items from the database instead of relying on an imprecise macroscopic model. This methodology is presented in the well-known case of dilute fibre suspensions (where it can be compared against closure-based macroscopic models) and in the case of suspensions of confined or electrically-charged fibres, for which state-of-the-art closures proved to be inadequate or simply do not exist.

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Section: Data-driven Simulationmentioning

confidence: 91%

Section: Confined Dilute Suspensions Of Rods Immersed In a Simple Shementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Data-Driven Upscaling of Orientation Kinematics in Suspensions of Rigid Fibres

Scheuer¹,

Ammar²,

Abisset-Chavanne³

et al. 2018

CMES

View full text Add to dashboard Cite

show abstract

“…Such a modeling framework allows recovering the Jeffery equation for a prolate spheroid with infinite aspect ratio [2] , as shown below. This rationale has been extended to study rigid [3] and deformable [4] clusters composed of rods, to address confinement effects [5,6] , to include higher-order gradients [7] , to consider viscoelastic surrounding fluids [8] , or to account for rods inertia [9] . Moreover, in [3] the authors proved that the Jeffery equation for general ellipsoids is recovered by using a rigid tri-dumbbell analog.…”

Section: Introductionmentioning

confidence: 99%

Viscous drag and rod orientation kinematics in an orthotropic fluid

Pierre

Chinesta

2019

Journal of Non-Newtonian Fluid Mechanics

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a b s t r a c tA model is proposed, where the evolution of the orientation of each fiber is coupled to the orientations of the surrounding fibers in the flow of a fiber-filled fluid and includes the effects of the fiber volume fraction and aspect ratio. This is performed by accounting for the effective behavior of the fiber-filled fluid, which is anisotropic although the fibers are embedded in an isotropic Newtonian fluid. The rotation of a fiber in these conditions is predicted by a dumbbell model, which allows an extension of Jeffery's equation to anisotropic cases. This involves the numerical evaluation of the drag force applied on a sphere in an orthotropic incompressible fluid, which is evaluated by finite element simulations. A simple fit is proposed for the practical use of the coupled model, which is applied finally to the orientation kinematics of a population of fibers in a simple shear flow, and the results are compared with the ones given by the standard uncoupled approach.

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Influence of flow–fiber coupling during mold-filling on the stress field in short-fiber reinforced composites

et al. 2023

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The anisotropic elastic properties of injection molded composites are fundamentally coupled to the flow of the fiber suspension during mold-filling. Regarding the modeling of mold-filling processes, both a decoupled and a flow–fiber coupled approach are possible. In the latter, the fiber-induced viscous anisotropy is considered in the computation of the flow field. This in turn influences the evolution of the fiber orientation compared to the decoupled case. This study investigates how flow–fiber coupling in mold-filling simulation affects the stress field in the solid composite under load based on the final elastic properties after fluid–solid transition. Furthermore, the effects of Newtonian and non-Newtonian polymer matrix behavior are investigated and compared. The entire process is modeled micromechanically unified based on mean-field homogenization, both for the fiber suspension and for the solid composite. Different numerical stabilization methods of the mold-filling simulation are discussed in detail. Short glass fibers with a typical aspect ratio of 20 and a volume fraction of 20% are considered, embedded in polypropylene matrix material. The results show that the flow–fiber coupling has a large effect on the fiber orientation tensor in the range of over ± 30% with respect to the decoupled simulation. As a consequence, the flow–fiber coupling affects the stress field in the solid composite under load in the range of over ± 10%. In addition, the predictions based on a non-Newtonian modeling of the matrix fluid differ significantly from the Newtonian setup and thus the necessity to consider the shear-thinning behavior is justified in a quantifiable manner.

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A multi-scale description of orientation in simple shear flows of confined rod suspensions

Cited by 27 publications

References 31 publications

Data-Driven Upscaling of Orientation Kinematics in Suspensions of Rigid Fibres

Data-Driven Upscaling of Orientation Kinematics in Suspensions of Rigid Fibres

Viscous drag and rod orientation kinematics in an orthotropic fluid

Influence of flow–fiber coupling during mold-filling on the stress field in short-fiber reinforced composites

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