Instability of the Near Wake behind a Circular Cylinder
Abstract
The spatial growth of a linear sinusoidal wave in the flow behind the attached eddies of a circular cylinder is investigated in order to determine the frequency in the vortex street. Two different types of dispersion relation are found depending on a Reynolds number expressed in terms of the wake halfwidth. An interesting feature in the Reynolds number range of about 3040 is a very strong dependence of the amplification rate on the frequency. Another interesting feature for the Reynolds number larger than 4050 is an existence of frequency at which the group velocity is infinitely large.
 Publication:

Journal of the Physical Society of Japan
 Pub Date:
 September 1976
 DOI:
 10.1143/JPSJ.41.1087
 Bibcode:
 1976JPSJ...41.1087N
 Keywords:

 Circular Cylinders;
 Flow Stability;
 Laminar Wakes;
 Near Wakes;
 Stream Functions (Fluids);
 Vortex Streets;
 Eigenvalues;
 Fourier Series;
 Group Velocity;
 OrrSommerfeld Equations;
 Reynolds Number;
 Sine Waves;
 Velocity Distribution;
 Wave Propagation;
 Fluid Mechanics and Heat Transfer