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
A differential pressure extensional rheometer on a chip with fully developed elongational flow
Heon Lee,Susan J. Muller +1 more
TL;DR: In this article, the first normal stress difference in a fluid element flowing along the channel centerline reaches its steady-state value early in the converging region, so that the time-averaged normal stress differences is approximately equal to the spatially averaged normal stress along a converging section.
Journal ArticleDOI
Rate constitutive theories for ordered thermoviscoelastic fluids: polymers
TL;DR: In this paper, the authors developed rate constitutive theories for compressible and incompressible ordered thermoviscoelastic fluids in Eulerian description, where the convected time derivative of the Cauchy stress tensor and the heat vector were derived for a desired order.
Journal ArticleDOI
Analytical solution for dynamic pressurization of viscoelastic fluids
TL;DR: In this paper, the authors analyzed the flow of simplified Phan-Thien-Tanner model fluid between parallel plates for the case where the upper plate moves at constant velocity, and two forms of the stress coefficient, linear and exponential, are used in the constitutive equation.
Journal ArticleDOI
Pattern selection in the Be´nard problem for a viscoelastic fluid
Michael Renardy,Yuriko Renardy +1 more
TL;DR: In this article, the authors discuss pattern selection in the Benard problem for a viscoelastic fluid and find that the rolls are the only bifurcating solution which can be stable.
Journal ArticleDOI
The confined flow of polyethylene melts past a cylinder in a planar channel
William H. Hartt,Donald G. Baird +1 more
TL;DR: In this article, the authors compared the results of numerical simulation of confined flow past a cylinder to birefringence data for two polymer melts, and showed that the PTT model does not correctly predict the rheological behavior of LDPE as a function of shear history because the time scale of structural recovery is much longer than the relaxation time associated with viscoelasticity.
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.