Passive control of circular cylinder wake in shallow flow


GÖZMEN B., AKILLI H. , ŞAHİN B.

MEASUREMENT, cilt.46, ss.1125-1136, 2013 (SCI İndekslerine Giren Dergi) identifier identifier

Özet

The control of vortex shedding of a circular cylinder in shallow water using a splitter plate located in the downstream of the circular cylinder was studied by employing particle image velocimetry (PIV) technique. Experiments were carried out in a water channel having a test section of 8000 mm x 1000 mm x 750 mm dimensions at a Reynolds number of 6250. The length of the splitter plate (L) was varied within the range of 0.5 <= L/D <= 2 with an increment of 0.5. The plate was submerged into water at different height ratios (h(p)/h(w)) such as 0.25, 0.5, 0.75 and 1.0. Mean velocity vector field, corresponding vorticity contours, streamline topologies and turbulent quantities were calculated using 300 instantaneous velocity vector field measured by PIV. As the ratio of h(p)/h(w) increases, the effect of the splitter plate on the suppression of the vortex shedding increases. Flow characteristics and examination of spectra indicate that Karman vortex shedding is attenuated pronouncedly for the cases of L/D >= 1 and h(p)/h(w) >= 0.75. The transverse Reynolds normal stress is more effective on the attenuation of turbulent kinetic energy than the streamwise Reynolds normal stress. The value of peak transverse Reynolds normal stress is reduced to 90% of that of the bare cylinder at most. (c) 2012 Elsevier Ltd. All rights reserved.