الفهرس 
INTRODUCTORY REMARKS
SINGLE CYLINDER FLOWOnly 14 pages are availabe for public view
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Abstract
This research aims to study the characteristics of the wake
behind twin cylinders. The cylinders were arranged in both
parallel side-by-side and staggered arrangements.
The cylinders used are of 4 mm diameter and were
mounted across a wind tunnel test section of 305 mm width,
305 mm beight and 610 mm length. The combination of the
cylinder and wind tunnel dimensions resulted in blockage ratio
of 2.67%. The main stream velocity was varied between 18 rnJs
and 20 rnJs, which are equivalent to cylinder Reynolds numbers
between 4750 and 5300. To completely understand the
characteristics of the wake behind the twin cylinders, the
cylinders were arranged in both parallel side-by-side and
staggered arrangements. The experiments for the side-by-side
arrangement were done at four cross-stream spacings; 2, 3, 4
and 6 times the cylinders diameter. For the staggered
arrangement two cross-stream spacing were chosen from 2 to
4 times the cylinder diameter, while the stream-wise spacing of
2 times and 4 times the cylinder diameter were employed at
each
The measurements of the mean velocity component in the
direction of the main stream and its turbulence intensity were
carried out by means of hot wire anemometer. The
measurements were performed at a sampling rate of 5000 Hz
and lasted for 10 seconds for each data point. Measurements
started at a distance of 5 times the cylinder diameter. Six other
measuring stations were examined at 10, 15, 20, 30, 50 and 100
times the cylinder diameter.
The results shows that the wakes of the side-by-side
cylinders tend to merge into a single wake for the cross-stream
spacing 2d and 3d at early stations equivalent to 15 and 30
times the cylinder diameter respectively and merges
completely at station equivalent to 20 and 50 times the cylinder