| Uniformly sheared turbulent flow with a turbulence Reynolds number Relambda in the range from 80 to 100 has been generated in a water tunnel and its instantaneous structure has been examined using flow visualization, laser Doppler velocimetry and particle image velocimetry. The flow was found to consist of regions with nearly uniform velocity, which were separated by relatively strong shear layers containing large vortices. The concentration of vortices and the probability distribution functions of their directions of rotation, strengths, sizes and shapes in three characteristic planes of the flow have been determined. These results, as well as hydrogen bubble visualisations and high-speed scans of injected dye patterns, support the hypothesis that horseshoe-shaped vortices are prevalent in this flow. |
