Measurements of some features of turbulence in wall-proximity

The friction velocity, turbulence quantities, and shear stress were determined in a pipe flow to obtain corrections that could be applied to diffuser flow. Instrumentation consisted of a static pressure tube, a Pitot tube, and hot-wire anemometers. Corrections were necessary to account for heat transfer effects near the wall affecting the hot-wire measurements, and were effected in the pipe by calculation of a Log Law velocity profile and in the diffuser by taking measurements in and out of the boundary layer. The flow data were taken at six free stream velocities of 2.5-12 m/sec. It was found that in a turbulent flow a linear velocity profile is present with a boundary condition of zero velocity at the wall. The local turbulence intensity reached a maximum at the outer edge of the sublayer. Boundary flows near the wall in a pipe or over a flat plate were concluded to be similar.