The mechanics of an organized wave in turbulent shear flow

Some preliminary results on the behavior of controlled wave disturbances introduced artificially into turbulent channel flow are reported. Weak lpanewave disturbances are introduced by vibrating ribbons near each wall. The amplitude and relative phase of the streamwise component of the induced wave is educed from a hot wire signal, allowing the wave speed and attenuation characteristics and the wave shape to be traced downstream. The normal component and wave Reynolds stress have been inferred from these data. It appears that OrrSommerfield theories attempted to data are inadequate for description of these waves.