Viscoelastic Pipe Flow is Linearly Unstable

Viscoelastic effects on drop deformation in a converging pipe flow

his paper reports finite-element simulations of drop deformation in converging flows in an xisymmetric conical geometry. The moving interface is captured using a diffuse-interface model nd accurate interfacial resolution is ensured by adaptive refinement of the grid. We have explored he effects of viscoelasticity on drop deformation when either the drop or the matrix is a Giesekus uid. Contrary...

Modeling of viscoelastic turbulent flow in channel and pipe

Effect of Elasticity Parameter on Viscoelastic Fluid in Pipe Flow Using Extended Pom-Pom Model

In this study prediction of the steady-state flow of branched polymer melts in pipe geometry with finite volume method is presented. Our analysis in this study revealed that;for normal-stress tqq , the XPP model can predict this tensor unlike the other viscoelastic models such as PTT or Gieskus which can not predict tqq...

On Poisson’s Ratio in Linearly Viscoelastic Solids

Poisson’s ratio in viscoelastic solids is in general a time dependent (in the time domain) or a complex frequency dependent quantity (in the frequency domain). We show that the viscoelastic Poisson’s ratio has a different time dependence depending on the test modality chosen; interrelations are developed between Poisson’s ratios in creep and relaxation. The difference, for a moderate degree of ...

Oscillating flow of a viscoelastic fluid in a pipe with the fractional Maxwell model

The unidirectional oscillating flow of a viscoelastic fluid with the fractional Maxwell model is studied. The flow is produced by a periodic pressure gradient in an infinite straight pipe. Exact solutions are obtained in the time and frequency domains by using Fourier transform. The fractional Maxwell model exhibits resonance phenomena similar to that of the Maxwell model. However, the number o...