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A new constitutive equation derived from network theory
Nhan Phan Thien,Roger I. Tanner +1 more
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In this paper, a constitutive equation is derived from a Lodge-Yamamoto type of network theory for polymeric fluids, where the network junctions are not assumed to move strictly as points of the continuum but allowed a certain "effective slip".Abstract:
A constitutive equation is derived from a Lodge—Yamamoto type of network theory for polymeric fluids. The network junctions are not assumed to move strictly as points of the continuum but allowed a certain “effective slip”. The rates of creation and destruction of junctions are assumed to depend on the instantaneous elastic energy of the network, or equivalently, the average extension of the network strand, in a simple manner. Agreement between model predictions and the I.U.P.A.C. data on L.D.P.E. is good.read more
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Theoretical study of the flow in a fluid damper containing high viscosity silicone oil: Effects of shear-thinning and viscoelasticity
TL;DR: In this article, the authors used the Carreau-Yasuda (CY) and Phan-Thien and Tanner (PTT) constitutive equations to simulate the flow inside a fluid damper where a piston reciprocates sinusoidally inside an outer casing containing high-viscosity silicone oil, at various excitation frequencies.
Journal ArticleDOI
On the predictive/fitting capabilities of the advanced differential constitutive equations for branched LDPE melts
TL;DR: In this paper, predictive/fitting capabilities of the XPP, PTT-XPP and modified Leonov constitutive equations are compared in both steady as well as transient shear and uniaxial elongational flows using two, highly branched LDPE materials (Escorene LD165BW1 and Bralen RB0323).
Journal ArticleDOI
Computational analysis of techniques to determine extensional viscosity from entrance flows
TL;DR: In this paper, a re-examination of entrance flows using numerical simulations is presented, which shows that entrance pressure drops do depend on the steady extensional viscosity, provided the extension rate in the entrance flow is large enough.
Journal ArticleDOI
Fully three-dimensional, time-dependent numerical simulations of Newtonian and viscoelastic swirling flows in a confined cylinder ☆: Part I. Method and steady flows
TL;DR: In this paper, a fully 3D numerical method using an implicit finite volume formulation is developed in the cylindrical coordinate system to simulate the vortex breakdown in terms of Reynolds number (Re) and the height to radius ratio (H/R), as well as the time, observed in experimental visualisations are exactly reproduced for Newtonian flows.
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Leading contribution: multiaxial elongations of polyisobutylene and the predictions of several network theories
A. Demarmels,J. Meissner +1 more
TL;DR: Theories de reseaux; comparaison entre les predictions theoriques and les resultats experimentaux as discussed by the authors ; comparaisons entre the predictions theorique and les results experimentaux
References
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Journal ArticleDOI
The Visco-elastic Properties of Network Structure I. General Formalism
TL;DR: In this article, the authors derived the stress-strain-time (S − S − T )relation at each instance of macroscopic observations by using the statistical mechanical considerations of equilibrium states.
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Constitutive equations from molecular network theories for polymer solutions
TL;DR: In this article, constitutive equations based on the network models of Yamamoto, Lodge, and Kaye are re-derived in a common notation involving the use of base vectors embedded in the deforming macroscopic continuum.
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Anisotropic Fluid Theory: A Different Approach to the Dumbbell Theory of Dilute Polymer Solutions
R. J. Gordon,W. R. Schowalter +1 more
TL;DR: In this paper, the authors used the continuum theory of anisotropic fluids, as developed by Ericksen and others, to formulate an expression for the time derivative of the end-to-end vector of a linear macromolecule when used in conjunction with the equation describing the distribution function for a dilute solution of dumbbell elements.