Skip to main content
Log in

Stokes flow in a mixer with changing geometry

  • Published:
Journal of Engineering Mathematics Aims and scope Submit manuscript

Abstract

A slow-flow mixing device that mimics a natural mixing technique is described. Analytical, numerical and experimental results are presented for the `translating, rotating mixer', which illustrate its mixing effectiveness. In large part, this effectiveness is due to the fact that its geometry changes with time, a feature rare in mathematically tractable slow-flow mixing models. The mixer consists of a large circular cylinder filled with fluid, which is stirred by a circular cylindrical `rod' that moves around in the fluid. The stirring rod may also rotate about its axis. The velocity field is calculated explicitly for the mixer, and its mixing action is simulated numerically. Through a complex-variable formulation of the problem, the energy input required for various mixing protocols may readily be determined, and in turn suggestions for efficient mixing using the device are offered. To validate the analytical and numerical results, tracer-advection experiments are performed, using a simple experimental rig and a variety of mixing protocols, providing encouraging agreement with numerical simulation.

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

  1. V.V. Meleshko, O.S. Galaktionov, G.W.M. Peters and H.E.H. Meijer, Three-dimensional mixing in Stokes flow: the partitioned pipe mixer problem revisited. Eur. J. Mech. B/Fluids 18 (1999) 783–792.

    Google Scholar 

  2. C.R. Thomas, Problems of shear in biotechnology. In: M.A. Winkler (ed.), Chemical Engineering Problems in Biotechnology. Critical Reports on Applied Chemistry (1990) Vol. 29, pp. 23–93.

  3. H. Aref, Stirring by chaotic advection. J. Fluid Mech. 143 (1984) 1–21.

    Google Scholar 

  4. J.M._Ottino, The kinematics of mixing: stretching, chaos, and transport. Cambridge Texts in Applied Mathematics. Cambridge University Press (1989) 364 pp.

  5. S.C. Jana, M. Tjanjadi and J.M. Ottino, Chaotic mixing of viscous fluids by periodic changes in geometry: baffled cavity flow. AIChE J. 40 (1994) 1769–1781.

    Google Scholar 

  6. V.V. Meleshko and H. Aref, A blinking rotlet model for chaotic advection. Phys. Fluids 8 (1996) 3215–3217. (Errata in Phys. Fluids 10 (1998) 1543.)

    Google Scholar 

  7. H. Aref and S. Balachandar, Chaotic advection in a Stokes flow. Phys. Fluids 29 (1986) 3515–3521.

    Google Scholar 

  8. H. Aref and S.W. Jones, Enhanced separation of diffusing particles by chaotic advection. Phys. Fluids A 1 (1989) 470–474.

    Google Scholar 

  9. T. Atobe and M. Funakoshi, Chaotic motion of fluid particles due to the alternate rotations of two eccentric cylinders. J. Phys. Soc. Japan 63 (1994) 1738–1753.

    Google Scholar 

  10. T. Atobe, M. Funakoshi and S. Inoue, Orbital instability and chaos in the Stokes flow between two eccentric cylinders. Fluid Dyn. Res. 16 (1995) 115–129.

    Google Scholar 

  11. B.Y. Ballal and R.S. Rivlin, Flow of a Newtonian fluid between eccentric rotating cylinders: inertial effects. Arch. Rat. Mech. Anal. 62 (1976) 237–294.

    Google Scholar 

  12. J. Chaiken, R. Chevray, M. Tabor and Q.M. Tan, Experimental study of Lagrangian turbulence in a Stokes flow. Proc. R. Soc. Lond. A 408 (1986) 165–174.

    Google Scholar 

  13. J. Chaiken, C.K. Chu, M. Tabor and Q.M. Tan, Lagrangian turbulence and spatial complexity in a Stokes flow. Phys. Fluids 30 (1987) 687–694.

    Google Scholar 

  14. G.B. Jeffery, The rotation of two circular cylinders in a viscous fluid. Proc. R. Soc. Lond. A101 (1922) 169–174.

    Google Scholar 

  15. J.Y. Kazakia and R.S. Rivlin, Flow of a Newtonian fluid between eccentric rotating cylinders and related problems. Stud. Appl. Math. 58 (1978) 209–247.

    Google Scholar 

  16. W.E. Langlois, Slow viscous flow. New York: MacMillan (1964) 229 pp.

    Google Scholar 

  17. C. Pozrikidis, Little book of streamlines. Academic Press (1999) 148 pp.

  18. G.H. Wannier, A contribution to the hydrodynamics of lubrication. Q. Appl. Math. 8 (1950) 1–32.

    Google Scholar 

  19. A.T. Chwang and T.Y.-T. Wu, Hydromechanics of low-Reynolds-number flow. Part 2. Singularity method for Stokes flows. J. Fluid Mech. 67 (1975) 787–815.

    Google Scholar 

  20. R.A. Frazer, On the motion of circular cylinders in a viscous fluid. Phil. Trans. R. Soc. Lond. A 225 (1926) 93–130.

    Google Scholar 

  21. T.W. Secomb and A.W. El-Kareh, A model for motion and sedimentation of cylindrical red-cell aggregates during slow blood flow in narrow horizontal tubes. J. Biomech. Eng. 116 (1994) 243–249.

    Google Scholar 

  22. A.C. Stevenson, Complex potentials in two-dimensional elasticity. Proc. R. Soc. Lond. A184 (1945) 129–179.

    Google Scholar 

  23. G.B. Jeffery, Plane stress and plane strain in bipolar coordinates. Phil. Trans. R. Soc. Lond. A221 (1921) 265–293.

    Google Scholar 

  24. L.M. Milne-Thomson, Plane elastic systems. Berlin: Springer–Verlag (1968) 211 pp.

    Google Scholar 

  25. D.J. Jeffrey and Y. Onishi, The slow motion of a cylinder next to a plane wall. Q. Jl. Mech. Appl. Math. 34 (1981) 129–137.

    Google Scholar 

  26. J.F. Trahan and R.G. Hussey, The Stokes drag on a horizontal cylinder falling toward a horizontal plane. Phys. Fluids 28 (1985) 2961–2969.

    Google Scholar 

  27. L.M. Milne-Thomson, Theoretical hydrodynamics. New York: Macmillan and Co. (1968).

    Google Scholar 

  28. H. Hasimoto and O. Sano, Stokeslets and eddies in creeping flow. Ann. Rev. Fluid Mech. 12 (1980) 335–363.

    Google Scholar 

  29. H.A. Lorentz, Eene algemeene stelling omtrent de beweging eener vloeistof met wrijving en eenige daaruit afgeleide gevolgen. Zittingsverslag van de Koninklijke Akademie van Wetenschappen te Amsterdam 5 (1896) 168–175. Translated into English by H.K. Kuiken, A general theorem on the motion of a fluid with friction and a few results derived from it. J. Eng. Math. 30 (1996) 19–24.

    Google Scholar 

  30. J.R. Blake, A note on the image system for a stokeslet in a no-slip boundary. Proc. Camb. Phil. Soc. 70 (1971) 303–310.

    Google Scholar 

  31. J.R. Blake and A.T. Chwang, Fundamental singularities of viscous flow. Part I: the image systems in the vicinity of a stationary no-slip boundary. J. Eng. Math. 8 (1974) 23–29.

    Google Scholar 

  32. J.R. Blake and S.R. Otto, Ciliary propulsion, chaotic filtration and a ‘blinking’ stokeslet. J. Eng. Math. 30 (1996) 151–168.

    Google Scholar 

  33. N. Liron and J.R. Blake, Existence of viscous eddies near boundaries. J. Fluid Mech. 107 (1981) 109–129. 34. K.B. Ranger, Eddies in two dimensional Stokes flow. Int. J. Engng Sci. 18 (1980) 181–190. 35. A. Avudainayagam and B. Jothiram, No-slip images of certain line singularities in a circular cylinder. Int. J. Engng Sci. 25 (1987) 1193–1205. 36. J.M. Dorrepaal, M.E. O'Neill and K.B. Ranger, Two-dimensional Stokes flows with cylinders and line singularities. Mathematika 31 (1984) 65–75. 37. A. Avudainayagam and B. Jothiram, A circle theorem for plane Stokes flows. Q. Jl. Mech. Appl. Math. 41 (1988) 383–393. 38. S.K. Sen, Circle theorems for steady Stokes flow. J. Appl. Math. Phys. (ZAMP) 40 (1989) 139–146. 39. J.H. Michell, The inversion of plane stress. Proc. Lond. Math. Soc. 34 (1901) 134–142. 40. C. Pozrikidis, Introduction to theoretical and computational fluid dynamics. Oxford: Oxford University Press (1997) 876 pp. 41. D.J. Acheson, Elementary fluid dynamics. Oxford Applied Mathematics and Computing Science Series. Oxford: The Clarendon Press (1990) 397 pp. 42. M. Charles and J. Wilson, Fermentor design. In: B.K. Lydersen, N.A. D'Elia and K.L. Nelson (eds.), Bioprocess Engineering: Systems, Equipment and Facilities. John Wiley and Sons (1994), pp. 5–67. 43. M.A. Winkler, Problems in fermenter design and operation. In: M.A. Winkler (ed.), Chemical Engineering Problems in Biotechnology. Critical Reports on Applied Chemistry (1990) Vol. 29, pp. 215–350.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Finn, M.D., Cox, S.M. Stokes flow in a mixer with changing geometry. Journal of Engineering Mathematics 41, 75–99 (2001). https://doi.org/10.1023/A:1011840630170

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1023/A:1011840630170

Navigation