S. Krishnamoorthy and J. S. Marshall
The University of Iowa
This photograph shows a slice of the boundary-layer fluid shed by a
cylinder (yellow) as wraps around a columnar vortex (red). The cylinder is traversed
toward the columnar vortex from left to right. The image is obtained using laser-induced
fluorescence with the yellow dye (Rhodamine chloride 590) released into the cylinder
boundary layer from small holes along the leading edge of the cylinder and the red dye
(Sulfurhodamine 640) released at the top of the vortex and carried downward by the vortex
axial flow. Light illumination is provided by a vertical sheet from the green line of a
continuous argon ion laser with wavelength in the range 457-514 nm. The sketch on the
right gives an interpretation of the loop-like structure of the secondary vorticity field
ejected from the cylinder boundary layer.
Krishnamoorthy, S., Gossler, A.A. and Marshall, J.S., "Normal vortex interaction
with a circular cylinder," AIAA Journal, Vol. 37, No. 1, 1999, pp. 50-57.
Gossler, A.A. and Marshall, J.S., "Simulation of normal vortex-cylinder
interaction in a viscous fluid," Journal of Fluid Mechanics, Vol. 431, 2001,