Studies of the Nonlinear Dynamics of Fluid Systems.

Abstract

Under ONR support we carried out an experimental study of the generalized hydrodynamic behavior of cellular patterns far from onset. We showed the basic qualitative effectiveness of the phase dynamics approach in modeling this behavior for both ordered and turbulent flows in the Taylor-Couette system. Although the experiments involved a specific system, the phase equations that describe them are determined by the pattern symmetries, so the results should generalize to other systems. In addition we performed a series of experiments on flows in the Taylor-Dean system, the flow between independently rotating concentric cylinders with a partially filled gap. By adjusting the rotation speeds of the two cylinders it is possible to tune the velocity profile across the gap over a wide range, and hence produce a large variety of flow patterns. We studied in detail several novel patterns and their evolution upon increasing the relevant control parameter. Finally, in a different area entirely, we studied two distinct liquid crystal systems. The first was a liquid crystal layer subjected to a noisy control parameter, which resulted in a state diagram in which the statistical probability density characteristics served as the distinguishing feature of the different states. The second was a study of phase winding in a thin layer of a liquid crystal subjected to rotationally induced shear. The outcome of this project is a better understanding of highly nonequilibrium ordered and turbulent patterns in both simple and complex fluid systems, and of the ability of phase dynamics to model long-wavelength low-frequency behaviors in some cases.

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1995
Accession Number
ADA299567

Entities

People

  • C. D. Andereck

Organizations

  • Ohio State University

Tags

Communities of Interest

  • Advanced Electronics
  • Biomedical
  • C4I
  • Weapons Technologies

DTIC Thesaurus Topics

  • Boundary Layer
  • Brushless Dc Motors
  • Cellular Structures
  • Chemistry
  • Computational Fluid Dynamics
  • Computational Science
  • Flow Visualization
  • Fluid Dynamics
  • Fluid Flow
  • Fungi
  • Hydrodynamics
  • Physics Laboratories
  • Refractive Index
  • Standing Waves
  • Three Dimensional
  • Turbulent Mixing
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Fluid Dynamics.
  • Materials Science and Engineering.
  • Neural Network Machine Learning.