Application of the Stanton Tube to the Measurements of Wall Shear Stress on a Flat Plate with Polymer Ejection
DAVID W TAYLOR NAVAL SHIP RESEARCH AND DEVELOPMENT CENTER BETHESDA MD
Pagination or Media Count:
An experimental investigation was made to determine the effects on drag of injecting aqueous solutions of polyethylene oxide Polyox WSR-301 into the turbulent boundary layer of a flat plate. The local mean wall shear stress was measured with a Stanton tube located in the laminar sublayer. Diffusion of the polymer in the boundary layer was also investigated by analysis of fluid samples withdrawn from the flat plate surface. In addition, a related but independent experimental turbulent pipe flow study was undertaken to determine any changes in Stanton tube sensitivity caused by the viscoelasticity of the polymer solutions. The wall friction on the plate was determined with and without polymer injection and the results compared well with available shear data. The measured wall shear stresses showed reductions of up to 50 percent with polymer injection and decreased with increasing mean wall polymer concentration.
- Fluid Mechanics