A TURBULENT MIXING LENGTH FORMULATION FOR NON-NEWTONIAN POWER LAW FLUIDS

The velocity profiles for non-Newtonian power law fluids are investigated and the friction factor is determined for pipe flow at high Reynolds numbers. The total shear stress is equated to the sum of the laminar power law stress and the turbulent stress, the latter based on the Prandtl mixing length. The analysis uses Van Driests' model for variation of the mixing length near the wall to yield a continuous velocity and shear stress distribution for incompressible turbulent flow. The shear stress equation is solved in terms of generalized parameters to yield velocity profiles near the wall as a function of the non-Newtonian fluid index, N. Pipe flow is investigated by integrating the flow equation over the pipe radius, and the friction factor is determined. It is found that the theory agrees will with the results of previous analysis and experiment, while anomalous experimental results are matched using the proper values of power law index and mixing length parameter.

• Corporate Authors:

  American Institute of Aeronautics and Astronautics

  1290 Avenue of the Americas
  New York, NY  United States  10019
• Authors:
  • Hecht, A M
• Publication Date: 1972-1

Media Info

• Features: References;
• Pagination: p. 21-26
• Serial:
  • Journal of Hydronautics
  • Volume: 6
  • Issue Number: 1
  • Publisher: American Institute of Aeronautics and Astronautics

Subject/Index Terms

• TRT Terms: Boundary layer; Drag; Nonnewtonian flow; Pipe flow; Turbulence; Turbulent boundary layer; Velocity
• Old TRIS Terms: Drag reduction; Velocity profiles
• Subject Areas: Design; Marine Transportation;

Filing Info

• Accession Number: 00032136
• Record Type: Publication
• Source Agency: American Institute of Aeronautics and Astronautics
• Files: TRIS
• Created Date: Apr 21 1972 12:00AM