TURBULENT CHARACTERISTICS OF DRAG-REDUCING FLOWS

Recently much interest in turbulent flows of dilute polymer solutions has developed in connection with the B.A. Toms' phenomenon. This phenomenon, i.e., the reduction of frictional losses relative to pure solvent, has begun to attract in particular the attention of civil engineers concerned with the hydraulic transport of solids and dredge spoil for considerable distances over land. Turbulence measurements went made in water and in a polyethylene oxide aqueous solution, using hot-film anemometry. Mean velocities, turbulence intensities, energy spectra and energy-dissipation rates were measured in a turbulent smooth-pipe flow. Mean flow structure showed that the mean velocity follows P.S. Virk's interactive-layer profile, and that the wall shear velocity is the proper velocity scale for polymer flows. Using J.L. Lumley's concept of an effective viscosity, the polymer spectra were cast into universal form and compared with Newtonian spectra. Results coincide reasonably well with the universal equilibrium theory. The major effect of the polymer additive appears to be an increase of the dissipative scales of the turbulence without significantly altering the basic structure of the flow, except near the wall.

• Corporate Authors:

  International Association for Hydraulic Research

  Room 61, Box 177
  Delft,   Netherlands 
• Authors:
  • Alonso, C V
  • Klaus, W H
  • Wylie, K F
• Publication Date: 1976

Media Info

• Features: References;
• Pagination: p. 103-113
• Serial:
  • Journal of Hydraulic Research
  • Volume: 14
  • Issue Number: 2
  • Publisher: International Association for Hydraulic Research

Subject/Index Terms

• TRT Terms: Additives; Drag; Flow; Polymers; Shear stress; Turbulence; Velocity; Walls
• Candidate Terms: Turbulent flow
• Old TRIS Terms: Drag reduction; Polymer additives; Velocity profiles; Wall shear stress
• Subject Areas: Design; Marine Transportation;

Filing Info

• Accession Number: 00144306
• Record Type: Publication
• Source Agency: Engineering Index
• Files: TRIS
• Created Date: Jan 16 1977 12:00AM