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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
Citations
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Squeezing Flows of Vaginal Gel Formulations Relevant to Microbicide Drug Delivery
Sarah L. Kieweg,David F. Katz +1 more
TL;DR: This study determined the best squeezing flow models and summary parameters for six test gels of two compositions, cellulose and polyacrylic acid (PAA) and found that for some gels it was preferable to deduce model input parameters directly from squeezing flow experiments, and indicated that yield stresses may be a strong determinant of squeezing flow mechanics.
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Divergent flow in contractions
Manuel A. Alves,Robert J. Poole +1 more
TL;DR: In this article, the authors reported the results of a systematic numerical investigation, using the upper-convected Maxwell model, of viscoelastic flow through smooth planar contractions of various contraction ratios with particular emphasis placed on the divergent flow regime.
Journal ArticleDOI
Yielding the yield stress analysis: A thorough comparison of recently proposed elasto-visco-plastic (EVP) fluid models
TL;DR: In this paper, the authors examine and compare five constitutive models, which have been recently proposed to describe the behavior of elasto-visco-plastic fluids, in simple rheometric flows, i.e. simple-shear, uniaxial elongation and large amplitude oscillatory tests and in the complex flow generated by a falling spherical particle.
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Cone-and-plate flow of the Oldroyd-B fluid is unstable
TL;DR: In this article, it was shown that the creeping cone-and-plate flow of an Oldroyd-B fluid is unstable with respect to an infinitesimal disturbance.
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Impact of the constitutive equation and singularity on the calculation of stick-slip flow: The modified upper-convected maxwell model (MUCM)
TL;DR: In this paper, a modified upper-convected Maxwell (MUCM) model is proposed which partially alleviates this difficulty and yields stress fields that reduce to the a symptotic expressions for a Newtonian fluid near singularities at non-deformable boundaries.
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.
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.