FORMATION OF LONGITUDINAL VORTICES ON A CONCAVE SURFACE
Xiaohua Wu* and Paul A. Durbin
Stanford University and Iowa State University
This image shows longitudinal vortices developed from passing wakes near the
pressure surface of a turbine cascade. These newly discovered vortices are neither
produced, nor sustained by the usual Gortler instability; rather, they are a consequence
of severely straining the passing wakes. The visualization was derived from a numerical
simulation, and used the vortex identification method of Jeong and Hussain. For further
details, see Wu and Durbin (2001a,b).
 J. Jeong and F. Hussain, "On the identification of a vortex", Journal of
Fluid Mechanics, 285, 69-94, 1995.
 X. Wu and P. A. Durbin, "Wake distortion in a turbine passage",
Physics of Fluids, 13, pp. S9, 2001a, special edition featuring winning entries from
the 18th Annual Picture Gallery of Fluid Motion exhibit.
 X. Wu and P. A. Durbin, "Evidence of longitudinal vortices evolved
from distorted wakes in a turbine passage", Journal of Fluid Mechanics 446, pp.