DAVID W TAYLOR NAVAL SHIP RESEARCH AND DEVELOPMENT CENTER BETHESDA MD DEPT OF HYDROMECHANICS
In certain Reynolds number regimes vortices are shed periodically from a smooth circular cylinder which moves normal to its axis through a viscous fluid. This alternate shedding of vortices induces a fluctuating lift force, in a direction perpendicular to its motion. A small fluctuating drag force is also induced in the direction of motion with a frequency of twice the vortex shedding frequency. For an elastic cylinder or an elastically mounted cylinder, if the frequency at which the vortices are shed is approximately equal to the free frequency of vibration of the cylinder, resonance can occur and the amplitude of vibration of the cylinder may become quite large. This phenomenon is responsible for the serious vibration problems of towed cables, submarine perioscopes, and other strut appendages subject to these unsteady hydrodynamic forces. The present work was undertaken to repeat and extend some of the measurements made in former investigations, to collect the data on magnetic tape, and to analyze the results of a high-speed computer.