Surface Hydrodynamic Modes on Concentrated Polymer Solutions and Gels

1989 ◽  
Vol 177 ◽  
Author(s):  
J. L. Harden ◽  
P. A. Pincus ◽  
H. Pleiner
Keyword(s):  
Surface Tension ◽  
Strong Coupling ◽  
Polymer Solutions ◽  
Fluid Model ◽  
Polymer Concentration ◽  
Polymer Gels ◽  
Hydrodynamic Modes ◽  
Surface Modes ◽  
Two Fluid Model ◽  
Two Fluid

ABSTRACTWe present a coupled two-fluid model for hydrodynamic surface modes on concentrated polymer solutions and swollen polymer gels. This model is used to investigate such surface modes in the limit of strong coupling. We discuss the form of the modes as a function of polymer concentration and the effects of chain diffusion and surface tension on the nature of these modes.

A two-fluid model for surface modes on concentrated polymer solutions and gels

Langmuir ◽  
1989 ◽  
Vol 5 (6) ◽  
pp. 1436-1438 ◽  
Author(s):  
J. L. Harden ◽  
H. Pleiner ◽  
P. A. Pincus
Keyword(s):  
Polymer Solutions ◽  
Fluid Model ◽  
Surface Modes ◽  
Two Fluid Model ◽  
Two Fluid

scholarly journals Shear Banding in 4:1 Planar Contraction

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 417 ◽  
Author(s):  
Soroush Hooshyar ◽  
Natalie Germann
Keyword(s):  
Fluid Model ◽  
Shear Banding ◽  
Polymer Concentration ◽  
Shear Bands ◽  
Mass Conservation ◽  
Industrial Applications ◽  
Flow Recirculation ◽  
Two Fluid Model ◽  
Planar Contraction ◽  
Two Fluid

We study shear banding in a planar 4:1 contraction flow using our recently developed two-fluid model for semidilute entangled polymer solutions derived from the generalized bracket approach of nonequilibrium thermodynamics. In our model, the differential velocity between the constituents of the solution allows for coupling between the viscoelastic stress and the polymer concentration. Stress-induced migration is assumed to be the triggering mechanism of shear banding. To solve the benchmark problem, we used the OpenFOAM software package with the viscoelastic solver RheoTool v.2.0. The convection terms are discretized using the high-resolution scheme CUBISTA, and the governing equations are solved using the SIMPLEC algorithm. To enter into the shear banding regime, the uniform velocity at the inlet was gradually increased. The velocity increases after the contraction due to the mass conservation; therefore, shear banding is first observed at the downstream. While the velocity profile in the upstream channel is still parabolic, the corresponding profile changes to plug-like after the contraction. In agreement with experimental data, we found that shear banding competes with flow recirculation. Finally, the profile of the polymer concentration shows a peak in the shear banding regime, which is closer to the center of the channel for larger inlet velocities. Nevertheless, the increase in the polymer concentration in the region of flow recirculation was significantly larger for the inlet velocities studied in this work. With our two-fluid finite-volume solver, localized shear bands in industrial applications can be simulated.

scholarly journals Natural modes of the two-fluid model of two-phase flow

2021 ◽  
Vol 33 (3) ◽  
pp. 033324
Author(s):  
Alejandro Clausse ◽  
Martín López de Bertodano
Keyword(s):  
Two Phase Flow ◽  
Fluid Model ◽  
Phase Flow ◽  
Two Phase ◽  
Natural Modes ◽  
Two Fluid Model ◽  
Two Fluid

Self-consistent hydrodynamic two-fluid model of vortex plasma

2021 ◽  
Vol 33 (3) ◽  
pp. 037116
Author(s):  
Victor L. Mironov
Keyword(s):  
Fluid Model ◽  
Self Consistent ◽  
Two Fluid Model ◽  
Two Fluid

scholarly journals Mathematical study on two-fluid model for flow of K–L fluid in a stenosed artery with porous wall

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
R. Ponalagusamy ◽  
Ramakrishna Manchi
Keyword(s):  
Theoretical Study ◽  
Fluid Model ◽  
Porous Wall ◽  
Governing Equations ◽  
Rate Of Increase ◽  
Special Cases ◽  
Stenosed Artery ◽  
Flow Through ◽  
Two Fluid Model ◽  
Two Fluid

AbstractThe present communication presents a theoretical study of blood flow through a stenotic artery with a porous wall comprising Brinkman and Darcy layers. The governing equations describing the flow subjected to the boundary conditions have been solved analytically under the low Reynolds number and mild stenosis assumptions. Some special cases of the problem are also presented mathematically. The significant effects of the rheology of blood and porous wall of the artery on physiological flow quantities have been investigated. The results reveal that the wall shear stress at the stenotic throat increases dramatically for the thinner porous wall (i.e. smaller values of the Brinkman and Darcy regions) and the rate of increase is found to be 18.46% while it decreases for the thicker porous wall (i.e. higher values of the Brinkman and Darcy regions) and the rate of decrease is found to be 10.21%. Further, the streamline pattern in the stenotic region has been plotted and discussed.

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