Skip to main content
Log in

Approximate solutions for drag coefficient of bubbles moving in shear-thinning elastic fluids

  • Short Communications
  • Published:
Rheologica Acta Aims and scope Submit manuscript

Abstract

The drag coefficient for bubbles with mobile or immobile interface rising in shear-thinning elastic fluids described by an Ellis or a Carreau model is discussed. Approximate solutions based on linearization of the equations of motion are presented for the highly elastic region of flow. These solutions are in reasonably good agreement with the theoretical predictions based on variational principles and with published experimental data.

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.

Abbreviations

C D :

Drag coefficient

E * :

Differential operator [E * 2 = 2/∂ξ2 + (sinθ/ξ 2)∂/∂θ(1/sinθ ⋅ ∂/∂θ)]

El :

Ellis number\([ = \eta _0 U_\infty /\sqrt 2 R\tau _{1/2} ]\)

F D :

Drag force

K :

Consistency index in the power-law model for non-Newtonian fluid

n :

Flow behaviour index in the Carreau and power-law models

P :

Dimensionless pressure [=(p − p 0)/η0 (U /R)]

p :

Pressure

R :

Bubble radius

Re 0 :

Reynolds number [= 2R U ϱ/η0]

Re′ :

Reynolds number defined for the power-law fluid [= (2R)n U 2−n ϱ/K]

r :

Spherical coordinate

t :

Time

U :

Terminal velocity of a bubble

u :

Velocity

Wi :

Weissenberg number

α :

Ellis model parameter

Δ :

Rate of deformation

η :

Apparent viscosity

η 0 :

Zero shear rate viscosity

η :

Infinite shear rate viscosity

θ :

Spherical coordinate

λ :

Parameter in the Carreau model

λ * :

Dimensionless time [=λ/(U /R)]

ξ :

Dimensionless length [=r/R]

Π :

Second invariant of rate of deformation tensors

Π * :

Dimensionless second invariant of rate of deformation tensors [=Π/(U /R)2]

Π τ :

Second invariant of stress tensors

Π *τ :

Dimensionless second invariant of second invariant of stress tensor [=Π τ 20 (U /R)2]

ϱ :

Fluid density

τ :

Shear stress

τ * :

Dimensionless shear stress [=τ/η 0 (U /R)]

τ 1/2 :

Ellis model parameter

τ 2/*1 :

Dimensionless Ellis model parameter [=τ 1/2/η 0(U /R)]

ψ :

Stream function

ψ * :

Dimensionless stream function [=ψ/U R 2]

References

  1. Chhabra RP, Uhlherr PHT, Boger DV (1980) J Non-Newtonian Fluid Mech 6:187

    Google Scholar 

  2. Crochet MJ (1982) In: Gallagher RH, Norrie DH, Oden JT, Zienkiewicz OC (eds), Finite Elements in Fluids, vol 4. John Wiley & Sons, New York

    Google Scholar 

  3. Leslie FM (1961) Quart J Mech Appl Math 14:36

    Google Scholar 

  4. Caswell B, Schwarz WH (1962) J Fluid Mech 13:417

    Google Scholar 

  5. Giesekus H (1963) Rheol Acta 3:59

    Google Scholar 

  6. Ultman JS, Denn MM (1971) Chem Eng J 2:81

    Google Scholar 

  7. Mena B, Caswell B (1974) Chem Eng J 8:125

    Google Scholar 

  8. Leal LG (1979) J Non-Newtonian Fluid Mech 5:33

    Google Scholar 

  9. Tiefenbruck G, Leal LG (1982) J Non-Newtonian Fluid Mech 10:115

    Google Scholar 

  10. Wagner MG, Slattery JC (1971) Amer Inst Chem Eng J 17:1198

    Google Scholar 

  11. Moo-Young M, Hirose T (1972) Can J Chem Eng 50:128

    Google Scholar 

  12. Shirotsuka T, Kawase Y (1974) Chem Eng (Japan) 38:797

    Google Scholar 

  13. Tiefenbruck GF, Leal LG (1980) J Non-Newtonian Fluid Mech 7:257

    Google Scholar 

  14. Chhabra RP, Uhlherr PHT (1980) Rheol Acta 19:187

    Google Scholar 

  15. Chhabra RP, Uhlherr PHT (1980) Can J Chem Eng 58:124

    Google Scholar 

  16. Chhabra RP, Tiu C, Uhlherr PHT (1981) Rheol Acta 20:346

    Google Scholar 

  17. Chhabra RP, Tiu C, Uhlherr PHT (1981) Can J Chem Eng 59:771

    Google Scholar 

  18. Hirose T, Moo-Young M (1969) Can J Chem Eng 67:265

    Google Scholar 

  19. Acharya A, Mashelkar RA, Ulbrecht J (1976) Rheol Acta 15:454

    Google Scholar 

  20. Kawase Y, Ulbrecht JJ (1981) Chem Eng Commun 8:213

    Google Scholar 

  21. Mohan V, Venkateswarlu D (1976) Int J Multiphase Flow 2:571

    Google Scholar 

  22. Mohan V, Raghuraman J (1976) Can J Chem Eng 54:228

    Google Scholar 

  23. Bird RB (1965) Can J Chem Eng 43:161

    Google Scholar 

  24. Boger DV (1977) Nature 265:126

    Google Scholar 

  25. Hopke SW, Slattery JC (1970) Amer Inst Chem Eng J 16:224

    Google Scholar 

  26. Wasserman ML, Slattery JC (1964) Amer Inst Chem Eng J 10:383

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Kawase, Y., Moo-Young, M. Approximate solutions for drag coefficient of bubbles moving in shear-thinning elastic fluids. Rheol Acta 24, 202–206 (1985). https://doi.org/10.1007/BF01333248

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF01333248

Key words

Navigation