FINITE ELEMENT APPROXIMATION OF KINETIC DILUTE POLYMER MODELS WITH MICROSCOPIC CUT-OFF

We construct a Galerkin finite element method for the numerical approximation of weak solutions to a coupled microscopic-macroscopic bead-spring model that arises from the kinetic theory of dilute solutions of polymeric liquids with noninteracting polymer chains. The model consists of the unsteady i...

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Main Authors: Barrett, J, Sueli, E
Format: Journal article
Language:English
Published: 2011
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author Barrett, J
Sueli, E
author_facet Barrett, J
Sueli, E
author_sort Barrett, J
collection OXFORD
description We construct a Galerkin finite element method for the numerical approximation of weak solutions to a coupled microscopic-macroscopic bead-spring model that arises from the kinetic theory of dilute solutions of polymeric liquids with noninteracting polymer chains. The model consists of the unsteady incompressible Navier-Stokes equations in a bounded domain Ω ⊂ ℝ d, d = 2 or 3, for the velocity and the pressure of the fluid, with an elastic extra-stress tensor as right-hand side in the momentum equation. The extra-stress tensor stems from the random movement of the polymer chains and is defined through the associated probability density function that satisfies a Fokker-Planck type parabolic equation, crucial features of which are the presence of a centre-of-mass diffusion term and a cut-off function β L(̇):= min(̇,L) in the drag and convective terms, where L ≫ 1. We focus on finitely-extensible nonlinear elastic, FENE-type, dumbbell models. We perform a rigorous passage to the limit as the spatial and temporal discretization parameters tend to zero, and show that a (sub)sequence of these finite element approximations converges to a weak solution of this coupled Navier-Stokes-Fokker-Planck system. The passage to the limit is performed under minimal regularity assumptions on the data. Our arguments therefore also provide a new proof of global existence of weak solutions to Fokker-Planck-Navier-Stokes systems with centre-of-mass diffusion and microscopic cut-off. The convergence proof rests on several auxiliary technical results including the stability, in the Maxwellian-weighted H 1 norm, of the orthogonal projector in the Maxwellian-weighted L 2 inner product onto finite element spaces consisting of continuous piecewise linear functions. We establish optimal-order quasi-interpolation error bounds in the Maxwellian-weighted L 2 and H 1 norms, and prove a new elliptic regularity result in the Maxwellian-weighted H 2 norm. © EDP Sciences, SMAI, 2010.
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spelling oxford-uuid:5033cf47-5ffe-44af-a052-bbe3bfa5b1c52022-03-26T16:12:09ZFINITE ELEMENT APPROXIMATION OF KINETIC DILUTE POLYMER MODELS WITH MICROSCOPIC CUT-OFFJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:5033cf47-5ffe-44af-a052-bbe3bfa5b1c5EnglishSymplectic Elements at Oxford2011Barrett, JSueli, EWe construct a Galerkin finite element method for the numerical approximation of weak solutions to a coupled microscopic-macroscopic bead-spring model that arises from the kinetic theory of dilute solutions of polymeric liquids with noninteracting polymer chains. The model consists of the unsteady incompressible Navier-Stokes equations in a bounded domain Ω ⊂ ℝ d, d = 2 or 3, for the velocity and the pressure of the fluid, with an elastic extra-stress tensor as right-hand side in the momentum equation. The extra-stress tensor stems from the random movement of the polymer chains and is defined through the associated probability density function that satisfies a Fokker-Planck type parabolic equation, crucial features of which are the presence of a centre-of-mass diffusion term and a cut-off function β L(̇):= min(̇,L) in the drag and convective terms, where L ≫ 1. We focus on finitely-extensible nonlinear elastic, FENE-type, dumbbell models. We perform a rigorous passage to the limit as the spatial and temporal discretization parameters tend to zero, and show that a (sub)sequence of these finite element approximations converges to a weak solution of this coupled Navier-Stokes-Fokker-Planck system. The passage to the limit is performed under minimal regularity assumptions on the data. Our arguments therefore also provide a new proof of global existence of weak solutions to Fokker-Planck-Navier-Stokes systems with centre-of-mass diffusion and microscopic cut-off. The convergence proof rests on several auxiliary technical results including the stability, in the Maxwellian-weighted H 1 norm, of the orthogonal projector in the Maxwellian-weighted L 2 inner product onto finite element spaces consisting of continuous piecewise linear functions. We establish optimal-order quasi-interpolation error bounds in the Maxwellian-weighted L 2 and H 1 norms, and prove a new elliptic regularity result in the Maxwellian-weighted H 2 norm. © EDP Sciences, SMAI, 2010.
spellingShingle Barrett, J
Sueli, E
FINITE ELEMENT APPROXIMATION OF KINETIC DILUTE POLYMER MODELS WITH MICROSCOPIC CUT-OFF
title FINITE ELEMENT APPROXIMATION OF KINETIC DILUTE POLYMER MODELS WITH MICROSCOPIC CUT-OFF
title_full FINITE ELEMENT APPROXIMATION OF KINETIC DILUTE POLYMER MODELS WITH MICROSCOPIC CUT-OFF
title_fullStr FINITE ELEMENT APPROXIMATION OF KINETIC DILUTE POLYMER MODELS WITH MICROSCOPIC CUT-OFF
title_full_unstemmed FINITE ELEMENT APPROXIMATION OF KINETIC DILUTE POLYMER MODELS WITH MICROSCOPIC CUT-OFF
title_short FINITE ELEMENT APPROXIMATION OF KINETIC DILUTE POLYMER MODELS WITH MICROSCOPIC CUT-OFF
title_sort finite element approximation of kinetic dilute polymer models with microscopic cut off
work_keys_str_mv AT barrettj finiteelementapproximationofkineticdilutepolymermodelswithmicroscopiccutoff
AT suelie finiteelementapproximationofkineticdilutepolymermodelswithmicroscopiccutoff