The Experts below are selected from a list of 36 Experts worldwide ranked by ideXlab platform
Julien Ferec - One of the best experts on this subject based on the ideXlab platform.
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fiber suspension in 2d Nonhomogeneous Flow the effects of Flow fiber coupling for newtonian and power law suspending fluids
Journal of Rheology, 2019Co-Authors: Dihya Mezi, G Ausias, Suresh G Advani, Julien FerecAbstract:A numerical study is presented for fiber suspension Flows through a parallel plate channel and a planar 4:1 contraction. Besides examining a Newtonian suspending fluid, a non-Newtonian matrix exhibiting a pseudoplastic behavior and describing a power-law model is also investigated. Furthermore, instead of using orientation tensors for the macroscopic constitutive modeling, the proposed approach addresses the macroscopic scale by describing the fiber orientation state with the probability distribution function (PDF). It enables us to eliminate the error introduced due to the closure approximation when using orientation tensor description as our numerical scheme solves the PDF in both the spatial and configurational spaces. This allows us to correctly implement expressions for both the fiber extra stress, especially for the suspending matrix displaying a pseudoplastic behavior, and the fiber orientation state, describing the configuration. Hence, these two constitutive relations for suspensions are used to perform simulations in which Flow and fiber orientation are fully coupled. Results are presented in planar geometries involving channel and 4:1 contraction Flows. It is found that the coupling effect flattens the velocity profile for both suspending fluids but has a small impact on the fiber orientation distributions at the geometry outlets. However, in the corner region where a vortex is observed, its magnitude increases with the coupling and this enhancement is more pronounced for the Newtonian suspending fluid. The Newtonian viscosity model is replaced with the Carreau model and results are compared to a bi-viscosity model. It gives qualitatively correct results if no rapid fiber orientation change occurs along the streamlines.A numerical study is presented for fiber suspension Flows through a parallel plate channel and a planar 4:1 contraction. Besides examining a Newtonian suspending fluid, a non-Newtonian matrix exhibiting a pseudoplastic behavior and describing a power-law model is also investigated. Furthermore, instead of using orientation tensors for the macroscopic constitutive modeling, the proposed approach addresses the macroscopic scale by describing the fiber orientation state with the probability distribution function (PDF). It enables us to eliminate the error introduced due to the closure approximation when using orientation tensor description as our numerical scheme solves the PDF in both the spatial and configurational spaces. This allows us to correctly implement expressions for both the fiber extra stress, especially for the suspending matrix displaying a pseudoplastic behavior, and the fiber orientation state, describing the configuration. Hence, these two constitutive relations for suspensions are used to ...
Hyoung Jin Choi - One of the best experts on this subject based on the ideXlab platform.
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The concentration equation of polymer solution in Nonhomogeneous Flow field
Journal of Molecular Liquids, 1994Co-Authors: Robert M. Crone, Myung S Jhon, Hyoung Jin ChoiAbstract:Abstract We have derived formally exact equations for the concentration of polymer in an externally imposed field using a time-dependent projection operator formalism. Two different bases are chosen as projectors; the initial state basis (equilibrium) at t=0 and the final state basis (steady state) at t→∞. The initial state basis is natural for studying transient behavior at short time and the final state basis is good for long time asymptotic behavior. Several methods have been suggested to obtain overall time dependences of the concentration, such as an interpolation model for the approximate initial and final state formulae. The general framework will be useful in studying the macroscopic characteristics of polymer solutions exposed to arbitrary Flow fields in confined geometries using the molecular inputs. A simple illustration of polymer migration caused by the Flow geometry and hydrodynamic interactions is provided. Calculation of the steady state probability function of polymer chains is also given.
Dihya Mezi - One of the best experts on this subject based on the ideXlab platform.
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fiber suspension in 2d Nonhomogeneous Flow the effects of Flow fiber coupling for newtonian and power law suspending fluids
Journal of Rheology, 2019Co-Authors: Dihya Mezi, G Ausias, Suresh G Advani, Julien FerecAbstract:A numerical study is presented for fiber suspension Flows through a parallel plate channel and a planar 4:1 contraction. Besides examining a Newtonian suspending fluid, a non-Newtonian matrix exhibiting a pseudoplastic behavior and describing a power-law model is also investigated. Furthermore, instead of using orientation tensors for the macroscopic constitutive modeling, the proposed approach addresses the macroscopic scale by describing the fiber orientation state with the probability distribution function (PDF). It enables us to eliminate the error introduced due to the closure approximation when using orientation tensor description as our numerical scheme solves the PDF in both the spatial and configurational spaces. This allows us to correctly implement expressions for both the fiber extra stress, especially for the suspending matrix displaying a pseudoplastic behavior, and the fiber orientation state, describing the configuration. Hence, these two constitutive relations for suspensions are used to perform simulations in which Flow and fiber orientation are fully coupled. Results are presented in planar geometries involving channel and 4:1 contraction Flows. It is found that the coupling effect flattens the velocity profile for both suspending fluids but has a small impact on the fiber orientation distributions at the geometry outlets. However, in the corner region where a vortex is observed, its magnitude increases with the coupling and this enhancement is more pronounced for the Newtonian suspending fluid. The Newtonian viscosity model is replaced with the Carreau model and results are compared to a bi-viscosity model. It gives qualitatively correct results if no rapid fiber orientation change occurs along the streamlines.A numerical study is presented for fiber suspension Flows through a parallel plate channel and a planar 4:1 contraction. Besides examining a Newtonian suspending fluid, a non-Newtonian matrix exhibiting a pseudoplastic behavior and describing a power-law model is also investigated. Furthermore, instead of using orientation tensors for the macroscopic constitutive modeling, the proposed approach addresses the macroscopic scale by describing the fiber orientation state with the probability distribution function (PDF). It enables us to eliminate the error introduced due to the closure approximation when using orientation tensor description as our numerical scheme solves the PDF in both the spatial and configurational spaces. This allows us to correctly implement expressions for both the fiber extra stress, especially for the suspending matrix displaying a pseudoplastic behavior, and the fiber orientation state, describing the configuration. Hence, these two constitutive relations for suspensions are used to ...
Robert M. Crone - One of the best experts on this subject based on the ideXlab platform.
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The concentration equation of polymer solution in Nonhomogeneous Flow field
Journal of Molecular Liquids, 1994Co-Authors: Robert M. Crone, Myung S Jhon, Hyoung Jin ChoiAbstract:Abstract We have derived formally exact equations for the concentration of polymer in an externally imposed field using a time-dependent projection operator formalism. Two different bases are chosen as projectors; the initial state basis (equilibrium) at t=0 and the final state basis (steady state) at t→∞. The initial state basis is natural for studying transient behavior at short time and the final state basis is good for long time asymptotic behavior. Several methods have been suggested to obtain overall time dependences of the concentration, such as an interpolation model for the approximate initial and final state formulae. The general framework will be useful in studying the macroscopic characteristics of polymer solutions exposed to arbitrary Flow fields in confined geometries using the molecular inputs. A simple illustration of polymer migration caused by the Flow geometry and hydrodynamic interactions is provided. Calculation of the steady state probability function of polymer chains is also given.
G Ausias - One of the best experts on this subject based on the ideXlab platform.
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fiber suspension in 2d Nonhomogeneous Flow the effects of Flow fiber coupling for newtonian and power law suspending fluids
Journal of Rheology, 2019Co-Authors: Dihya Mezi, G Ausias, Suresh G Advani, Julien FerecAbstract:A numerical study is presented for fiber suspension Flows through a parallel plate channel and a planar 4:1 contraction. Besides examining a Newtonian suspending fluid, a non-Newtonian matrix exhibiting a pseudoplastic behavior and describing a power-law model is also investigated. Furthermore, instead of using orientation tensors for the macroscopic constitutive modeling, the proposed approach addresses the macroscopic scale by describing the fiber orientation state with the probability distribution function (PDF). It enables us to eliminate the error introduced due to the closure approximation when using orientation tensor description as our numerical scheme solves the PDF in both the spatial and configurational spaces. This allows us to correctly implement expressions for both the fiber extra stress, especially for the suspending matrix displaying a pseudoplastic behavior, and the fiber orientation state, describing the configuration. Hence, these two constitutive relations for suspensions are used to perform simulations in which Flow and fiber orientation are fully coupled. Results are presented in planar geometries involving channel and 4:1 contraction Flows. It is found that the coupling effect flattens the velocity profile for both suspending fluids but has a small impact on the fiber orientation distributions at the geometry outlets. However, in the corner region where a vortex is observed, its magnitude increases with the coupling and this enhancement is more pronounced for the Newtonian suspending fluid. The Newtonian viscosity model is replaced with the Carreau model and results are compared to a bi-viscosity model. It gives qualitatively correct results if no rapid fiber orientation change occurs along the streamlines.A numerical study is presented for fiber suspension Flows through a parallel plate channel and a planar 4:1 contraction. Besides examining a Newtonian suspending fluid, a non-Newtonian matrix exhibiting a pseudoplastic behavior and describing a power-law model is also investigated. Furthermore, instead of using orientation tensors for the macroscopic constitutive modeling, the proposed approach addresses the macroscopic scale by describing the fiber orientation state with the probability distribution function (PDF). It enables us to eliminate the error introduced due to the closure approximation when using orientation tensor description as our numerical scheme solves the PDF in both the spatial and configurational spaces. This allows us to correctly implement expressions for both the fiber extra stress, especially for the suspending matrix displaying a pseudoplastic behavior, and the fiber orientation state, describing the configuration. Hence, these two constitutive relations for suspensions are used to ...