Laser Velocimeter Measurement of Reynolds Stress and Turbulence in Dilute Polymer Solutions
Measurements of Reynolds stress and axial and transverse turbulence intensities have been made in turbulent pipe flow of a dilute solution of high molecular weight polymer and compared to measurements made with pure water. A laser velocimeter capable of measuring these turbulence parameters has been developed and utilized.
Axial turbulence intensities are consistent in behavior and magnitude with previous polymer results and the measurements of transverse intensity and Reynolds stress are similarly well behaved and self consistent. Sublayer thickening in drag reducing polymer solution is observed, in consonance with earlier work. New results include demonstration that the turbulent shearing stress is reduced in the turbulent core by an amount proportional to the observed decrease in pressure gradient at the wall, and dramatically reduced near the wall to a thickness of several times that of the viscous sublayer in agreement with observed velocity profiles. Radial turbulence intensities are comparable with water in the turbulent core, but exhibit similar dramatic suppression near the wall region. Possible implications of these measurements toward the phenomenon of turbulent drag reduction are briefly discussed.
Logan, Samuel E., "Measurement of Reynolds Stress and Turbulence in Dilute Polymer Solution by Laser Velocimeter" (1973). Symposia on Turbulence in Liquids. 105.
3rd Biennial Symposium on Turbulence in Liquids (1973: Sep., Rolla, MO)
Chemical and Biochemical Engineering
Article - Conference proceedings
Turbulence in Viscoelastic Fluids
© 1973 University of Missouri--Rolla, All rights reserved.