## Search

Now showing items 1-10 of 19

#### Degradation in Cone-Plate Rheometry

(2018-07)

We analyze quantitatively the oxidative degradation of a sample in a cone-plate rheometer, as oxygen diffuses inward, radially, from the free boundary. We examine rheometer error mitigation by means of nitrogen blanketing, ...

#### Polymer Orientation Contributions in Large-Amplitude Oscillatory Shear Flow

(2017-01)

Previously, we used a dilute suspension of rigid dumbbells as a model for the dynamics for polymeric liquids in large-amplitude oscillatory shear (LAOS) flow. We then use dumbbell orientation to explain fluid elasticity. ...

#### Review of Nonlinear Oscillatory Shear Flow Notations and Presentations: Polymeric Liquids

(2018-12)

We review notations for, along with ways of presenting, the shear stress responses to large-amplitude oscillatory shear flow (LAOS). We find that the Fourier loss and storage viscosities to be the simplest primal notations ...

#### Orientation Distribution Function Pattern for Rigid Dumbell Suspensions In Any Simply Shear Flow

(2018-09)

For rigid dumbbells suspended in a Newtonian solvent, the viscoelastic response depends exclusively on the dynamics of dumbbell orientation. The orientation distribution function ψ (θ ,φ ,t) represents the probability of ...

#### Exact Coefficients for Rigid Dumbbell Suspensions for Steady Shear Flow Material Function Expansions

(2008-07)

From kinetic molecular theory, we can attribute the elasticity of polymeric liquids to macromolecular orientation. For a suspension of rigid dumbbells, subject to a particular flow field, we must first solve the diffusion ...

#### 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 ...

#### Power Series for Normal Stress Differences of Polymeric Liquids in Large-Amplitude Oscillator Shear Flow

(2018-04)

Exact solutions for normal stress differences in polymeric liquids subjected to largeamplitude oscillatory shear flow (LAOS) contain many Bessel functions, each appearing in infinite sums. For the simplest relevant model ...

#### Degradation in Parallel-Disk Rheometry

(2018-08)

We analyze quantitatively the oxidative degradation of a sample in a parallel-disk rheometer, as oxygen diffuses inward, radially, from the free boundary. We examine rheometer error mitigation by means of nitrogen blanketing, ...

#### Macromolecular Tumbling and Wobbling in Large-Amplitude Oscillatory Shear Flow

(2018-11)

For a suspension of rigid dumbbells, in any simple shear flow, we recently solved for the diffusion equation for the orientation distribution function by a power series expansion in the shear rate magnitude. In this paper, ...

#### 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 ...