We propose a simple and systematic description of the most used viscoelastic models by using a non-equilibrium thermodynamic approach, generally referred to as the internal variables theory. The main idea is to elevate the conformation tensor C describing the geometrical configuration of the macromolecules to the status of independent variable. It is shown that the sole knowledge of the Helmholtz free energy— whose explicit expression is provided by the kinetic theory—allows to derive the expressions of the polymeric stress tensor and the time evolution equation of the internal variable C, which represents the main ingredients of the rheological models. As illustrations, the Hookean, FENE-P Giesekus, and Bird’s encapsulated dumbbell models are discussed. For completeness, the results are compared with these provided by extended irreversible thermodynamics.

A mesoscopic thermodynamical description of rheological models

PALUMBO, Annunziata;
2012-01-01

Abstract

We propose a simple and systematic description of the most used viscoelastic models by using a non-equilibrium thermodynamic approach, generally referred to as the internal variables theory. The main idea is to elevate the conformation tensor C describing the geometrical configuration of the macromolecules to the status of independent variable. It is shown that the sole knowledge of the Helmholtz free energy— whose explicit expression is provided by the kinetic theory—allows to derive the expressions of the polymeric stress tensor and the time evolution equation of the internal variable C, which represents the main ingredients of the rheological models. As illustrations, the Hookean, FENE-P Giesekus, and Bird’s encapsulated dumbbell models are discussed. For completeness, the results are compared with these provided by extended irreversible thermodynamics.
2012
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11570/2436032
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 0
  • ???jsp.display-item.citation.isi??? 0
social impact