Spurt phenomena of the Johnson-Segalman fluid and related models

Kolkka, Robert W.; Malkus, David S.; Hansen, M. G.; Ierley, Glenn

doi:10.1016/0377-0257(88)85059-6

Cited by 118 publications

(53 citation statements)

References 19 publications

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“…In the last section we briefly discuss extensions of some of our results to models with several relaxation times and to time dependent shearings. Results related to those of section 2 have been obtained by Kolkka et al [7], [8]. We thank Professor B. Plohr who kindly brought these works to our attention (cf.…”

Section: U(x T) -(0 V Y(xt)) 'mentioning

confidence: 55%

Global existence and one-dimensional nonlinear stability of shearing motions of viscoelastic fluids of Oldroyd type

Guillopé¹,

Saut²

1990

ESAIM: M2AN

148

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Section: U(x T) -(0 V Y(xt)) 'mentioning

confidence: 55%

Global existence and one-dimensional nonlinear stability of shearing motions of viscoelastic fluids of Oldroyd type

Guillopé¹,

Saut²

1990

ESAIM: M2AN

148

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“…They concluded that the high shear rate layer propagates as far as possible into the capillary once the wall shear rate reaches the point where the shear stress is at its maximum. The question of how the high shear rate layer develops was examined in detail by Kolkka et al (1988) and by Malkus et al (1990) using the Johnson-Segalman constitutive equation modified by the addition of a small Newtonian viscosity. Marrucci and Grizzuty (1985) and Morrison and Larson (1992) have proposed that anomalous stress relaxation curves at large strains could be explained by strain inhomogeneities, and Morrison and Larson speculated that this phenomenon could be related to flow curve hysteresis.…”

Section: Rheological Explanations Of Oscillatory Flowmentioning

confidence: 99%

Role of slip and fracture in the oscillating flow of HDPE in a capillary

Hatzikiriakos

Dealy

1992

Journal of Rheology

196

123

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Certain polymers exhibit two distinct branches in their capillary flow curves (wall shear stress versus apparent wall shear rate). This gives rise to oscillatory flow in constant-piston-speed rheometers and to flow curve hysteresis in controlled-pressure rheometers. These curious phenomena have attracted considerable interest over a period of many years, but their basic mechanisms are still the subject of debate. Building on previous work we have developed a model that predicts all the essential features of the curves of pressure and flow rate versus time in the oscillatory flow regime. Fluid compressibility and the second branch of the flow curve are necessary features of the model, but fluid elasticity is found not to be an essential element. While our macroscopic measurements do not prove it conclusively, our data lead us to believe that on the high-flow-rate branch of the flow curve there is slip along a cylindrical fracture surface near the wall. The jump to the high-flow branch occurs when this fracture occurs, at an upper critical value of the shear stress, while the jump back to the low-flow branch occurs when adhesion is established at the fracture surface at a lower critical shear stress.

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“…Doi±Edwards theory predicts that stress passes through a maximum and then decreases with a further increase in the shear rate, which leads to mechanical instability in steady shearing [27]. Modification of the Doi±Edwards theory [28] and other theories, such as Johnson-Segalman and Giesekus models [16] predict a local stress minimum following the maximum.…”

Section: Introductionmentioning

confidence: 99%

Slipping fluids: a unified transient network model

Joshi

Lele

Mashelkar

2000

Journal of Non-Newtonian Fluid Mechanics

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Wall slip in polymer solutions and melts play an important role in fluid flow, heat transfer and mass transfer near solid boundaries. Several different physical mechanisms have been suggested for wall slip in entangled systems. We look at the wall slip phenomenon from the point of view of a transient network model, which is suitable for describing both, entangled solutions and melts. We propose a model, which brings about unification of different mechanisms for slip. We assume that the surface is of very high energy and the dynamics of chain entanglement and disentanglement at the wall is different from those in the bulk. We show that severe disentanglement in the annular wall region of one radius of gyration thickness can give rise to non-monotonic flow curve locally in that region. By proposing suitable functions for the chain dynamics so as to capture the right physics, we show that the model can predict all features of wall slip, such as flow enhancement, diameter-dependent flow curves, discontinuous increase in flow rate at a critical stress, hysteresis in flow curves, the possibility of pressure oscillations in extrusion and a second critical wall shear stress at which another jump in flow rate can occur. #

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Spurt phenomena of the Johnson-Segalman fluid and related models

Cited by 118 publications

References 19 publications

Global existence and one-dimensional nonlinear stability of shearing motions of viscoelastic fluids of Oldroyd type

Global existence and one-dimensional nonlinear stability of shearing motions of viscoelastic fluids of Oldroyd type

Role of slip and fracture in the oscillating flow of HDPE in a capillary

Slipping fluids: a unified transient network model

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