Flow visualisation studies in a square duct of internal dimensions 44.5 x 44.5 mm are reported. The flow marker is a stream of opaque white dye, released from a downstream facing stationary tube, and it is photographed through the plexiglass wall of the duct. The point of dye release can be traversed in a direction perpendicular to the duct wall and three locations are investigated, two in the core of the flow and one in the near- wall region. By using Is exposure times photographs are obtained of a dye dispersion cone and the cone angle is measured and related to the turbulence properties of the flow. Using water as the solvent various concentrations of the highly effective drag reducing polymer Polyox WSR-301 are explored and relationships obtained between cone angle and injection location, Reynolds number and drag reduction. The importance of turbulence suppression in the near-wall region of the flow is demonstrated to be closely linked with the drag reduction mechanism.
Sellin, R. H. J., "Flow Visualization Studies on Drag-Reducing Turbulent Flows" (1973). Symposia on Turbulence in Liquids. 103.
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.