EXPERIMENTAL INVESTIGATION OF FLOW STRUCTURE DOWNSTREAM OF PERMEABLE CYLINDERS

Year 2018, Volume: 2 Issue: 2, 54 - 59, 15.05.2018

Bengi Şanlı Hüseyin Akıllı

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

https://izlik.org/JA64NY94RC

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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