Elongational Perturbations on Nematic Liquid Crystal Polymers Under a Weak Shear

Abstract

The two-dimensional Smoluchowski equation is employed to study the effect of elongational perturbations on nematic liquid crystal polymers under a weak shear. We use the multiscale asymptotic analysis to show that 1 when the elongational perturbation is small relative to the weak shear, the orientational probability density function pdf tumbles periodically only in an intermediate range of polymer concentration; outside this intermediate range i.e., for very small and very large polymer concentration the orientational pdf converges to a steady state and there is no tumbling. 2 When the elongational perturbation is about 20% of the shear rate or larger, the intermediate range of tumbling disappears and the orientational pdf always converges to a steady state regardless of the polymer concentration. Our theoretical predictions are consistent with various earlier results based on the Leslie Ericksen theory C. V. Chaubal and L. G. Leal, J. Non-Newtonian Fluid Mech. 82, 22 1999 or analogous 3D numerical simulations M. G. Forest, R. Zhou, and Q. Wang, Phys. Rev. Lett. 93, 088301 2004 ; M. G. Forest, Q. Wang, R. Zhou, and E. Choate, J. Non-Newtonian Fluid Mech. 118, 17 2004].

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2007
Accession Number
ADA488435

Entities

People

  • Hong Zhou
  • Hongyun Wang

Organizations

  • Naval Postgraduate School

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Aspect Ratio
  • Crystals
  • Equations
  • Flow Fields
  • Kinetic Theory
  • Liquid Crystal Polymers
  • Liquid Crystals
  • Macromolecules
  • Mathematics
  • Molecules
  • Perturbations
  • Phase Transformations
  • Polymers
  • Probability
  • Steady State
  • Three Dimensional
  • Two Dimensional

Readers

  • Fluid Dynamics.
  • Polymer Science and Technology
  • Quantum spin resonance or Electron Paramagnetic Resonance spectroscopy.