The structure of turbulent motions was measured in a region surrounding the
blade tips of a Rushton turbine mixer. The tip vortices responsible for mi
cromixing were created in this region, as was the radial jet that drives th
e large-scale circulation responsible for macromixing. Measurements of inst
antaneous velocity fields in axial- radial planes showed large cycle-to-cyc
le variability relative to the mean. The average measurements of the azimut
hal vorticity and the Reynolds stresses in the radial-axial plane showed th
e growth and motion of the tip vortices as they drift away from the blades.
Radial and axial spatial derivatives were measured to assess various metho
ds of computing the turbulent viscous dissipation. The small scales were si
gnificantly anisotropic at the Reynolds numbers studied.