• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to project page

1997 Fiscal Year Final Research Report Summary

PATTERN FORMATION AND SYMMETRY OF FIELDS IN ELECTROHYDRODYNAMICSS IN LIQUID CRYSTALS

Research Project

Project/Area Number 08454107
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Research Field 物性一般(含基礎論)
Research InstitutionKYUHSU UNIVERSITY

Principal Investigator

KAI Shoichi  KYUSHU UNIV., DEPT.APPLIED SCIENCE,PROFESSOR, 工学部, 教授 (20112295)

Co-Investigator(Kenkyū-buntansha) HIDAKA Yoshiki  KYUSYU UNIV., DEPT.APPLIED SCIENCE,ASSIST PROF., 工学部, 助手 (70274511)
Project Period (FY) 1996 – 1997
KeywordsElectrohydrodynamics / Liquid Crystals / Homeotropic Alignment / Symmetry / Goldstone Mode / Soft-Mode Turbulence / Defect Chaos / Continuously Rotational Symmetry
Research Abstract

The electrohydrodynamic instability (EHD) in nematic liquid crystals is investgated using homeotropically aligned systems where the nematic director orients perpendicular to the electrodes. In homeotropically aligned EHD the system has a continuously rotational symmetry as well as a translational one. This symmetry leads to additional new Goldstone modes at onset of convections and dramatically changes the bifurcation properties as well as observed patterns. The obtained results in the present study are as follows.
1) In the system with additional Goldstone modes due to continuous rotational symmetry, a direct transition from nonconvective states to spatiotemporal chaos is observed.
2) The bifuration at onset occurs supercritically. The correlation time of macroscopic randam motions becomes longer inversely proportional to the deviation from the onset, that is, a critical slowing down phenomenon is observed. From this behavior the spatiotemporal chaos has been named the soft mode turbule … More nce (SMT) .
3) The stability of additional Goldstone modes can be controlled by application of magnetic field since magnetic fields induce the prefered axis and suppress the generation of the Goldstone modes. Therefore under superimposing strong magnetic fields periodic patterns are observed.
4) New type of zig-zag patterns are found out which are not predicted in currently available thcories.
5) It is clarified from these findings that driving forccs which result in SMT are induced by non-parallel orientation between the director and the wavevector of covective rolls.
6) Depending on the strength of magnetic fields there are two types of spatiotemporal chaos. The transition between them is clearly defined by looking the spatial power spectra of patterns and distribution functions of roll orientations.
7) The rolls exist either in all directions or only in the prefered directions induced by magnetic fields. Then the formet one is called SMT and the latter the defect turbulence.
Thus excess of symmetry can result in chaos and the intrinsic mechanism for direct transition to chaos from a spatially uniform state is destabilization of short-wavelength modes due to coupling with Goldstone modes of the spectrum. Based on these results, new theory will be expected in EHD. Less

  • Research Products

    (16 results)

All Other

All Publications (16 results)

  • [Publications] Yoshiki HIDAKA: "Dynamical Aspects of Spatiotemporal Chaos at the Onset of Electroconvection in Homeotropic Nematics" Journal of Physical Society of Japan. 66-11. 3329-32 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Yoshiki HIDAKA: "Soft-Mode Turbulence in Electrohydrodynamic Convection of a Homeotropically Aligned Nematic Layer" Physical Review. E56-6. R6256-59 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Yoshiki HIDAKA: "Formation and Dynamics of Convective Pattern in Homeotropic System of Nematic Liquid Crystals" Molecular Crystals and Liquid Crystals. 302. 385-390 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Yoshiki HIDAKA: "Dynamics of Eckhaus Modes in One-Dimensional Electroconvection Patterns in Nematics" Molecular Crystals and Liquid Crystals. 302. 357-362 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 甲斐 昌一: "液晶における散逸構造の物理" 高分子. 46-9. 681-4 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Shoichi KAI: "Pattern Forming Instabilities in Homeotropically Aligned LX" Journal of Physical Chemistry. 100-51. 19007-19016 (1996)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Shoichi KAI: "Complexity and Diversity(R.Nakamura ed.,)Diversity and Complexity of Patterns in Nonequilibrium Systems" Springer-Verlag, 204(9) (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Yoshiki HIDAKA: "Complexity and Diversity(R.Nakamura ed.,)Soft-Mode Turbulence in Electrohydrodynamic Convection" Springer-Verlag, 204(3) (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Shoichi KAI,Ken-ichi HAYASHI,Yoshiki HIDAKA: "Pattern Forming Instabilities in Homeotropically Aligned Liquid Crystals" J.Phys.Chem.vol.100, no.51.19007-16 (1996)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Yoshiki HIDAKA,Jong-Hoon HUH,Ken-ichi HAYASHI,Michael I.TRIBELSKY,Shoichi KAI: "Dynamical Aspects of Spatiotemporal Chaos at the Onset of Electroconvection in Homeotropic Nematics" J.Phys.Soc.Jpn.vol.66, no.11. 3329-32 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Yoshiki HIDAKA,Jong-Hoon HUH,Ken-ichi HAYASHI,Michael I.TRIBELSKY,Shoichi KAI: "Soft-Mode Turbulence in Electrohydrodynamic Convection of a Homeotropically Aligned Nematic Layr" Phys.Rev.E. vol.56, no.6. R6256-59 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Yoshiki HIDAKA,Ken-ichi HAYASHI,Shoichi KAI: "Formation and Dynamics of Convective Patterns in Homeotropic System of Nematic Liquid Crystals" Mol.Cryst.Liq.Cryst.vol.302. 385-90 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Yoshiki HIDAKA,Ken-ichi HAYASHI,Michael I.TRIBELSKY,Shoichi KAI: "Dynamics of Eckhaus Modes in One-Dimensional Electroconvection Patterns in Nematics" Mol.Cryst.Liq.Cryst.vol.302. 357-62 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Shoichi KAI: "Physics of Dissipative Structures in Liquid Crystals (in Japanese)" Polymer (Kohbunnshi). vol.46, no.9. 681-1 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Shoichi KAI: Dyversity and Cmplexity of Patterns in Nonequilibrium Systems-Pattern Formation in Electrohydrodynamic Instability-. Complexity and Diversity (R.Nakamura ed., Springer-Verlag, 99-107 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Yoshiki HIDAKA,Ken-ichi HAYASHI,Michael I.TRIBELSKY,Shoichi KAI: Soft-Mode Turbulence in Electrohydrodynamic Convection in Homeotropic System of Nematics. Complexity and Diversity (R.Nakamura ed.Springer-Veriag, 135-7 (1997)

    • Description
      「研究成果報告書概要(欧文)」より

URL: 

Published: 1999-03-16  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi