Abstract

An experimental study, based on streak photograph determination of instantaneous velocities, was directed at determining the structure of turbulence within the boundary layer and core regions of circular pipes. The measurements lend support to the ejection phenomenon as the mechanism controlling drag reduction.

A correlation factor, defined as the ratio of the observed number of positive instantaneous radial velocities, to the observed number of negative instantaneous radial velocities, suggests acceleration in the radial direction as the elements of fluid move through the sublayer. The correlation factor also provides information about the thickening of the boundary layer for drag reducers relative to the Newtonian case.

Radial turbulent intensity data for 0.01% aqueous solutions of Separan AP-30 were found to be markedly lower, at all radial positions, than the intensities for Newtonian fluids. The lowering of the radial intensities being ordered according to the amount of drag reduction.

Meeting Name

3rd Biennial Symposium on Turbulence in Liquids (1973: Sep., Rolla, MO)

Department(s)

Chemical and Biochemical Engineering

Comments

The financial support of NRC and the Dow Chemical Co. who donated the polymer are greatful ly acknowledged.

Document Type

Article - Conference proceedings

Presentation Type

Contributed Paper

Session

Turbulence in Viscoelastic Fluids

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 1973 University of Missouri--Rolla, All rights reserved.

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