Turbulence quantities and Reynolds stress in pipe flow of polymer solutions measured by two channel laser Doppler anemometry

Detailed measurement in turbulent liquid pipe flows with and without polymer additives are described. The measurements were carried out with laser Doppler anemometry (LDA). Laser Doppler anemometry, it is pointed out, does not have the disadvantages of probe type sensor errors, but requires the application of refractive index matching in order to permit near wall measurements of mean velocities and turbulence properties in pipe flows. A test section is described which was built to permit LDA measurements in the near wall region of a pipe flow by using an oil as fluid having the same refractive index as the glass of which the pipe is made. Detailed mean velocity and turbulence measurements in water are reported for various Reynolds numbers. Data are given for two Reynolds numbers composing the Newtonian flow data with those obtained in polymer flows. The data are discussed in detail and are compared with solutions of the Reynolds equations.