Journal ArticleDOI
A new constitutive equation derived from network theory
Nhan Phan Thien,Roger I. Tanner +1 more
Reads0
Chats0
TLDR
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
Citations
More filters
Journal ArticleDOI
Beads-on-string formation during filament pinch-off: Dynamics with the PTT model for non-affine motion
TL;DR: In this article, it was shown that the simulation of an elongating filament modeled by the Phan-Thien/Tanner (PTT) equation with the Gordon-Schowalter (GS) convected derivative, which allows nonaffine motion of polymer molecules in the continuum, results in the formation of the beads-on-string structure.
Journal ArticleDOI
Hyperbolic contraction measuring systems for extensional flow
TL;DR: In this paper, an experimental method for extensional measurements on medium viscosity fluids in contraction flow is evaluated through numerical simulations and experimental measurements, and the measured pressure drops are observed to exhibit the same trends as predicted in the numerical simulations, offering close correlation and tight predictive windows for experimental data capture.
Journal ArticleDOI
Melt exit flow modelling and experimental validation for fused filament fabrication: From Newtonian to non-Newtonian effects
TL;DR: In this paper , polypropylene (PP) FFF flow is simulated at a reference FFF temperature of 473 K with ANSYS Polyflow by inputting Phan-Thien-Tanner (PTT) viscoelastic parameters that have been previously validated, based on both rheological and conventional extrusion slit die swell measurements.
Journal ArticleDOI
A numerical stabilization framework for viscoelastic fluid flow using the finite volume method on general unstructured meshes
TL;DR: Investigating the entry‐flow problem of the 4:1 contraction benchmark, it is demonstrated that the numerical methods are robust over a wide range of Weissenberg numbers and significantly alleviate the high Weissenberg number problem.
Journal ArticleDOI
Computational modeling of impinging viscoelastic droplets
TL;DR: In this paper, a numerical study on the impingement and spreading of an isothermal viscoelastic droplet on a solid surface is presented, where the time-dependent incompressible Navier-Stokes equations are used to describe the fluid flow in the liquid droplet, whereas the viscoelingity in the moving droplet is described by the Giesekus constitutive equation.
References
More filters
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.
Journal ArticleDOI
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.
Journal ArticleDOI
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.