This thesis presents the results of a series of experiments conducted in an open flume to determine the effect of blockage on the drag coefficient of a circular cylinder in a free surface flow.
The range of parameters covered is
d/D: 2, 4, 6, 8, 10
w/D: 4, 6, 8, 9, 12, 16, 18, 24.
Re: 7.1 X 103 - 6.4 X 104
Fd: .192 - .806
Fd: .421 - 1.964
A strong correlation has been found in the plots of CD vs FD, and the form of these plots partly related to the changes in the surface structure of the wake. Except for small W/D ratios, the drag coefficient is found to be less than that which would be expected for two dimensional flow at the same Reynolds number.
Blockage corrections due to Woods (1961) and Haskell (1963) have been applied to the experimental data and found to collapse the range considerably. Both corrections give a very similar result.