Effects of Reynolds number and corner radius on twodimensional flow around hexdecagonal cylinders
Abstract
The viscous crossflow over hexadecagonal cylinders with varying corner radii was investigated for Reynolds numbers from 0.11.5 x 10 to the 6th and Mach numbers less than 0.2. Variations of static lift, drag, and total force coefficients and Strouhal number with variation in Reynolds number, corner radius, and windcylinder orientation were considered, as well as the variation of surface static pressure coefficients with angular position around the cylinders at selected values of Reynolds number, corner radius, and windcylinder orientation. It was found that hexadecagonal cylinders with corner radii as small as 17.5 percent of the radius of the inscribed circular cylinder have total force coefficients equal to or less than those of a circular cylinder over wide ranges of Reynolds numbers. Total force coefficients as much as 13.7 percent below the drag coefficient of a circular cylinder at the same Reynolds number were observed. In addition, supercritical static lift coefficients as large as 0.28 and Strouhal numbers between 0.25 and 0.30 were found. No distinct shedding frequency was observed at Reynolds numbers below 300,000 for cylinders with intermediate corner radii, while shedding started at a Reynolds number of 800,000, varying with corner radius and model orientation, and continued with increasing Reynolds number.
 Publication:

16th Fluid and Plasma Dynamics Conference
 Pub Date:
 July 1983
 Bibcode:
 1983fpdy.conf.....J
 Keywords:

 Aerodynamic Forces;
 Cross Flow;
 Cylindrical Bodies;
 Reynolds Number;
 Two Dimensional Flow;
 Viscous Flow;
 Flow Distribution;
 Fluid Dynamics;
 Pressure Distribution;
 Strouhal Number;
 Wind Tunnel Tests;
 Fluid Mechanics and Heat Transfer