Skip to main content
Log in

Compatibility of the generalized BMP model and the two-fluid Langevin formulations

  • Original Contribution
  • Published:
Rheologica Acta Aims and scope Submit manuscript

Abstract

The main objective of this work is to demonstrate the agreement between the two-fluid linear Langevin formulation and that described by the extended irreversible thermodynamics (EIT). The two-fluid model, originally proposed by de Gennes, has been widely analyzed by many authors in various flow situations, especially to compare predictions with experimental data of the structure factor in many complex flows. The canonical Langevin equations together with the fluctuation-dissipation theorem ensure consistent thermodynamic behavior for constitutive equations. Therefore, agreement between the EIT formulation and the two-fluid Langevin equations demonstrates the thermodynamic consistency of the EIT formulation. Extension of this analysis to include normal stresses is also considered.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

Download references

Acknowledgements

We acknowledge the financial support from project IN 100620 from DGAPA-UNAM and the scholarship CONACYT CVU 896737.

Glossary

\( \underset{\_}{\underset{\_}{B}} \)Strain tensor

\( \underset{\_}{\underset{\_}{L}} \)Rate of deformation tensor

\( \underset{\_}{\underset{\_}{D}} \)Symmetric part of the rate of strain tensor \( \underset{\_}{\underset{\_}{L}} \)

\( \underset{\_}{J} \)Mass flux

\( \nabla {\underset{\_}{J}}^s \)Is the symmetric part of the tensor \( \nabla \underset{\_}{J} \)

φ ≡ η−1 Is the fluidity (inverse of the viscosity)

\( {\varphi}_s\equiv {\eta}_s^{-1} \)Solvent fluidity

φo Fluidity at zero shear rate

φ Fluidity at high shear rates

G0 Elastic modulus

β0 Phenomenological coupling coefficient

β1 Coupling coefficient of the mass flux

β2 Phenomenological coefficient

\( {\underset{\_}{\underset{\_}{\sigma}}}_p \)Stress tensor

\( {\underset{\_}{\underset{\_}{\overset{\nabla }{\sigma}}}}_p \)Upper-convected derivative of the stress tensor

λ Relaxation time related to structure building

λmShear-dependent relaxation time

k Kinetic constant

μ Chemical potential

μNeqNon-equilibrium chemical potential

ϕ Dispersed phase concentration

\( \underset{\_}{v} \)Velocity vector

ρ Density

p Hydrostatic pressure

π Osmotic pressure

A Structural parameter

F Free energy

χ Osmotic susceptibility

ζ Friction coefficient

kb Boltzmann constant

T Temperature

Dc Cooperative diffusion coefficient

Kos Osmotic modulus

DG Diffusion coefficient of the micellar network

Θ Thermal noise

δ Denotes property fluctuation

δ(t − t) Dirac delta function

z \( =\nabla \nabla :\underset{\_}{\underset{\_}{\mathit{\mathsf{\sigma}}}} \)

\( S\left(\underset{\_}{q}\right) \)Structure factor

\( \underset{\_}{q} \)Scattering vector

\( \hat{q} \)Unit scattering vector

ω Frequency

\( \left\langle \underset{\_}{r}\ \underset{\_}{r}\right\rangle \)Configuration tensor

\( {\xi}_{ve}^2 \)Viscoelastic correlation length

\( \underset{\_}{\underset{\_}{\mathcal{I}}} \)Correlation matrix

\( {\mathcal{L}}_{ij} \)Onsager kinetic coefficients

\( {\mathcal{I}}_q \)Steady-state structure factor

N1 First normal stress difference

N2 Second normal stress difference

ψ  Normal stress coefficient

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to O. Manero.

Additional information

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Fierro, C., Bautista, F., García-Sandoval, J.P. et al. Compatibility of the generalized BMP model and the two-fluid Langevin formulations. Rheol Acta 60, 751–761 (2021). https://doi.org/10.1007/s00397-021-01290-4

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00397-021-01290-4

Keywords

Navigation