Abstract
Investigations in the present paper have been made theoretically on a breakdown and a development of the Karman vortex street in both positively and negatively buoyant wakes. Unsteady numerical solutions are obtained by means of time-dependent numerical analysis. To verify the validity. of the results of numerical analysis, results of flow visualization were compared with numerical solutions. The following results were obtained.
1. The natural convection from the cylinder has a remarkable influence on the Karman vortex street.
2. In the positively buoyant wake above a heated horizontal cylinder, the Karman vortex street breaks down.
3. In the negatively buoyant wake, the Karman vortex street develops.
