ESDU 79026 gives curves obtained by correlating experimental data drawn from a wide range of sources in the literature. The graphs give the drag in uniform two-dimensional flow of regular polygonal sections with from four (square-section) to 20 sides@ single- and double-wedge sections@ elliptical sections and a 12 sided elliptical section. The effect of corner rounding between the extremes of sharp-edged to the inscribed circle is considered. Factors are included to correct the data for turbulence (and a table gives values of the appropriate turbulence parameters in a wide range of conditions both atmospheric or in internal flow)@ the effect of aspect ratio@ and the effect of shear flow and taper. A method of calculating the centre of pressure and hence the overturning moment is also given. For the elliptical section@ data are included for the situation when the section is not aligned with the flow. A comprehensive worked example illustrates the application of the data to a multi-sided pylon supporting a power cable.
ESDU 79026 A-1980 history
1980ESDU 79026 A-1980 Mean fluid forces and moments on cylindrical structures: polygonal sections with rounded corners including elliptical shapes.