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#### Polymer Process Partitioning: Extruding Plastic Pipe

(2016-09-14)

When plastic pipe is solidified, it proceeds through a long cooling chamber. Inside this chamber, inside the hollow extrudate, the plastic is molten, and this inner surface solidifies last. Sag, the flow due to the ...

#### Startup Steady Shear Flow from the Oldroyd 8-Constant Framework

(2019-01)

One good way to explore fluid microstructure, experimentally, is to suddenly subject the fluid to a large steady shearing deformation, and to then observe the evolving stress response. If the steady shear rate is high ...

#### Padé Approximant for Normal Stress Differences in Large-Amplitude Oscillatory Shear Flow

(2017-11)

Analytical solutions for the normal stress differences in large-amplitude oscillatory shear flow (LAOS), for continuum or molecular models, normally take the form of the first few terms of a series expansion in the shear ...

#### Order in Oscillatory Shear Flow

(2018-12)

We examine the second order orientation tensor for the simplest molecular model relevant to a polymeric liquid in large-amplitude oscillatory shear flow (LAOS), the rigid dumbbell suspension. For this we use an approximate ...

#### Power Series for Shear Stress of Polymeric Liquid in Large-Amplitude Oscillatory Shear Flow

(2018-04)

xact solutions for shear stress in a polymeric liquid subjected to large-amplitude oscillatory shear flow (LAOS) contain many Bessel functions. For the simplest of these, for instance, the corotational Maxwell fluid, in ...

#### Exact Analytical Solution for Large-Amplitude Oscillatory Shear Flow

(2015-03-16)

When polymeric liquids undergo large-amplitude shearing oscillations, the shear stress responds as a Fourier series, the higher harmonics of which are caused by fluid nonlinearity. Previous work on large-amplitude oscillatory ...

#### Elastomers in Large-Amplitude Oscillatory Uniaxial Extension Revisited

(2017-07)

In this work, we subject elastomers to a fixed pre-stretch in uniaxial extension, ε p , upon which a large-amplitude, ε 0 , oscillatory uniaxial extensional (LAOE) deformation is superposed. We find that if both ε p and ε ...

#### Polymer Processing Partitioning Approach: Extruding Plastic Pipe

(2016-01)

The proposed thesis research aims at deepening our understanding of the flow of polymer melts through eccentric plastic pipe extrusion dies. Specifically, the proposed thesis research will explore how viscoelasticity affects ...

#### Bubble Growth From First Principles

(2016-07-05)

We consider the simplest relevant problem in the foaming of molten plastics, the growth of a single bubble in a sea of highly viscous Newtonian fluid, and without interference from other bubbles. This simplest problem has ...

#### Series Expansion for Shear Stress in Large-Amplitude Oscillatory Shear Flow From Oldroyd 8-Constant Framework

(2018-06)

When polymeric liquids undergo large-amplitude oscillatory shear flow (LAOS), the shear stress responds as a Fourier series, the higher harmonics of which are caused by the fluid nonlinearity, and the first harmonic of ...