EXPERIMENTAL INVESTIGATION OF FLOW STRUCTURE DOWNSTREAM OF PERMEABLE CYLINDERS

Year 2018, , 54 - 59, 15.05.2018

Bengi Şanlı Hüseyin Akıllı

https://doi.org/10.31127/tuje.349532

Abstract

Flow
structure downstream of permeable cylinders was investigated using high-image
density Particle Image Velocimetry technique in deep water. The free stream
velocity is U_∞= 156 mm/s, which corresponds to the Reynolds number
of Re=6250 based on the cylinder diameter D=37.5 mm. To reveal the effect of
the porosity, four different porosities (β= 0.4, 0.5, 0.6 and 0.7) were used.
This study showed that the usage of permeable cylinder decreases the occurrence
of large-scale vortical structures downstream of the bluff body. As the
porosity increases, turbulent kinetic energy, Reynolds shear stress and
intensity of turbulences decrease as a sign of attenuated fluctuations in the
wake region. For the permeable cylinders having the porosity higher than 0.6,
the flow behaves as there is no object in flow. 

Keywords

PIV, vortex shedding, permeable cylinder, Deep Water

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