简介:The wakes of wall mounted circular cylinders of very low
aspect ratio have been investigated in a wind tunnel. Besides
planar PIV, also high resolution tomographic PIV was used
to capture the flow phenomena downstream简介:The wakes of wall mounted circular cylinders of very low
aspect ratio have been investigated in a wind tunnel. Besides
planar PIV, also high resolution tomographic PIV was used
to capture the flow phenomena downstream of the cylinder.
By changing the velocity U¥ and the cylinder height h at a
constant aspect ratio L = h=D, a wide database of different
flow conditions was obtained. The resulting relative height of
the boundary layer thickness d was 0:6 h=d 2:5, while the
Reynolds number based on the length l between leading edge
and cylinder centre Rel was 57;000 Rel 188; 000. A pair of
counter-rotating vortices was found in the wake of the cylinder.
The rotation sense is such, that in the center of the wake a
positive vertical velocity component results. Also horseshoe
vortices were found next to these trailing vortices. The relative
height of the incoming boundary layer has a large impact on the
development, strength and dissipation of the vortex system.详细>