Dynamics of Rigid Fibers in a Planar Converging Channel

The influence of turbulence on the orientation state of a dilute suspension of stiff fibers at high Reynolds number in a planar contraction is investigated. High speed imaging and LDV techniques are used to quantify fiber orientation distribution and turbulent characteristics. A nearly homogenous, isotropic grid generated turbulent flow is introduced at the contraction inlet. Flow Reynolds number and inlet turbulent characteristics are varied in order to determine their effects on orientation distribution. The orientation anisotropy is shown to be accurately modelled by a Fokker-Planck type equation. Results show that rotational diffusion is highly influenced by inlet turbulent characteristics and decays exponentially with convergence ratio. Furthermore, the effect of turbulent energy production in the contraction is shown to be negligible. Also, the results show that the flow Reynolds number has negligible effect on the development of orientation anisotropy, and the influence of turbulence on fiber rotation is negligible for mathrm{Pe_r}> 10. It was concluded that inertia induced fiber motion played a negligible role in the experiments.

Department dc:contributor.department

Engineering

Grantor dc:publisher

Georgia Institute of Technology

Year dc:date.issued

2005

Author dc:creator

• Brown, Matthew Lee

Advisors dc:contributor.advisor

• Aidun, Cyrus K.
• Empie, Jeff

Committee members dc:contributor.committeemember

• Larry Forney
• Mostafa Ghiaasiaan
• Victor Breedveld

• Extensional flow
• Orientation diffusion model
• Paper forming
• Fiber orientation
• Planar contraction
• Turbulence

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/1853/6894

OAI identifier oai:identifier

oai:repository.gatech.edu:1853/6894