Shock tube study of the drag coefficient of a sphere in a nonstationary flow
Abstract
A review of previous attempts to study the drag coefficient of a sphere in a nonstationary flow, experimentally, is given. A detailed account of the present study is presented. A shock tube facility was used for inducing relatively high acceleration in small spheres laid on the shock tube floor. The spheres acceleration resulted from the drag force imposed by the postshock wave flow. Using double exposure holography, the spheres trajectory could be constructed accurately. Based upon such trajectories, the spheres drag coefficient was evaluated for a relatively wide range of Reynolds number (6000  101,000). It was found that the obtained values for the sphere drag coefficient were significantly larger than those obtained in a similar steady flow case.
 Publication:

Proceedings of the Royal Society of London Series A
 Pub Date:
 August 1993
 DOI:
 10.1098/rspa.1993.0102
 Bibcode:
 1993RSPSA.442..231I
 Keywords:

 Acceleration (Physics);
 Drag Coefficients;
 Gas Flow;
 Shock Tubes;
 Spheres;
 Unsteady Flow;
 Equations Of Motion;
 Mach Number;
 Reynolds Number;
 Steady Flow;
 Fluid Mechanics and Heat Transfer