An investigation of the near-wake flow structure of a cylinder with guiding plates

An investigation of the near-wake flow structure of a cylinder with guiding plates

Ekinci, Fırat (Adana Science and Technology University)
Fırat, Erhan (Munzur University)
Ozkan, G.M. (TU Delft Fluid Mechanics; Çukurova University)
Akıllı, Hüseyin (Çukurova University)

2018

In this study, the flow behind a circular cylinder with a pair of outer identical guiding plates was investigated using particle image velocimetry (PIV) for various angular positions of the plates (i.e. α=±70°, ±100°, and ±130°). The gaps between these plates and cylinder are equal and are 0.3D. Experiments were carried out at a subcritical Reynolds (Re=ρ·U_∞·D/μ) number of 7500, based on the cylinder diameter (D) and the flow velocity (U_∞). The features of the near-wake with and without the guiding plates were interpreted in terms of patterns of time-averaged vorticity and streamlines, time-averaged and fluctuating velocity components. The spectral analysis was also carried out to determine the time-dependent variation of the transverse velocity at given locations in the near-wake. Two-dimensional computations of flow around circular cylinders with and without guiding plates have also been performed to predict the timeaveraged and root-mean-square of force coefficients of the various models. It was seen that the guiding plates at an appropriate angular position can lead to substantial attenuation, or retardation, of the process of large-scale vortex formation in the near-wake, thus can lead to vortex-induced vibration (VIV) suppression without any increase in drag.

http://resolver.tudelft.nl/uuid:4f4c7ca5-c8dc-400e-955b-faf754d4b96e

https://doi.org/10.1051/epjconf/201818002024

2101-6275

EPJ Web of Conferences, 180

EFM17 - Experimental Fluid Mechanics 2017, 2017-11-21 → 2017-11-24, Mikulov, Czech Republic

Institutional Repository

journal article

© 2018 Fırat Ekinci, Erhan Fırat, G.M. Ozkan, Hüseyin Akıllı