Propagative Structures and Localization in the Convection of a Liquid Crystal

  • A. Joets
  • R. Ribotta
Part of the Springer Series in Synergetics book series (SSSYN, volume 41)


Fluids driven to convection under an external forcing can exhibit above some threshold a well-defined ordered spatial structure. Usually the obtained state is stationary. The Rayleigh-Bénard rolls in a small rectangular box, or the Taylor-Couette vortices are classical examples of isotropic systems. Convection in a nematic liquid crystal, under either an electric field or a thermal gradient, provides a particularly interesting example of an anisotropic system. With respect to the former, this system possesses an intrinsic preferred direction which imposes a unique direction for the wavevector of the basic roll structure over the whole plane of the layer [l]. Then the experiments can be performed in very extended layers where the boundary effects can be neglected. We present here experimental results which show that, inside some other range in frequency, the basic structure at threshold is no longer stationary and homogeneous in space, but appears as localised domains of traveling waves. We analyse the fluid motion in the propagating pattern and we suggest some elements for an interpretation of the travelling wave and for the localisation. Our results show some similarity with those found in the Rayleigh-Bénard convection of binary mixtures [2,3]. However, our observations indicate clearly that the localization inside small domains is not due to finite size effects induced by solid lateral boundaries.


Nematic Liquid Crystal Molecular Orientation Normal Roll Convective Roll Anisotropic System 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    A. Joets, R. Ribotta: in Cellular Structures in Instabilities ed. by J. E. Wesfreid and S. Zaleski, Lecture Notes in Physics (Springer 1984)Google Scholar
  2. A. Joets, R. Ribotta: J. Physique 47, 595 (1986)CrossRefGoogle Scholar
  3. 2.
    R. Walden, P. Kolodner, A. Passner, C.M. Surko: Phys.Rev.Lett. 55, 496 (1985)CrossRefADSGoogle Scholar
  4. E. Moses, V. Steinberg: Phys.Rev. A 34. 693 (1986)CrossRefADSGoogle Scholar
  5. 3.
    E. Moses, J. Fineberg, V. Steinberg: Phys. Rev. A 35, 2757 (1987)CrossRefADSGoogle Scholar
  6. R. Heinrichs, G. Ahlers, D. S. Cannell: Phys. Rev. A 35, 2761 (1987)ADSGoogle Scholar
  7. 4.
    E.F. Carr: Mol. Cryst. Liq. Cryst. 7, 253 (1969)CrossRefGoogle Scholar
  8. W. Helfrich: J. Chem. Phys. 51. 4092 (1969)CrossRefADSGoogle Scholar
  9. Orsay Liquid Crystal Group: Phys. Rev. Lett. 25. 1640 (1970)CrossRefADSGoogle Scholar
  10. 5.
    P.A. Penz: Phys. Rev. Lett. 24, 1405 (1970)CrossRefADSGoogle Scholar
  11. 6.
    W. Zimmermann, L. Kramer: Phys. Rev. Lett. 55, 402 (1985)CrossRefADSGoogle Scholar
  12. 7.
    N.V. Madhusudana, V.A. Raghunathan, K.R. Sumathy: Pramana J.of Physics 28, L311 (1987)CrossRefADSGoogle Scholar
  13. 8.
    P. Atten, R. Moreau: J. de Mecanique, 11, 470 (1972)Google Scholar
  14. 9.
    P.G. de Gennes: C. R. Acad. Sci. 280B. 9 (1975)Google Scholar
  15. E. Guyon, P. Pieranski: C. R. Acad. Sci. 280B. 187 (1975)Google Scholar
  16. 10.
    M.C. Cross: Phys. Rev. Lett. 57, 2935 (1986)CrossRefADSGoogle Scholar
  17. 11.
    A.C. Newell: in Pattern Formation and Pattern Recognition. H. Haken ed. (Spinger.Berlin 1979), and also in Solitons in Condensed Matter Physics.Google Scholar
  18. A.R. Bishop, T. Schneider ed. Springer Series in Solid State Science (Springer 1978)Google Scholar
  19. 12.
    H.R. Brand, P.S. Lomdahl, A.C. Newell: Physica 23D, 345 (1986)ADSGoogle Scholar
  20. A.C. Newell: these proceedingsGoogle Scholar
  21. 13.
    C.S. Bretherton, E.A. Spiegel: Phys. Lett. 96, 152 (1983)CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1988

Authors and Affiliations

  • A. Joets
    • 1
  • R. Ribotta
    • 1
  1. 1.Laboratoire de Physique des SolidesUniversité de Paris SudOrsay CedexFrance

Personalised recommendations