Interference effects on the flow-induced vibrations of a circular cylinder

This paper presents the results of tests on the interference effects of a single in-line, rigid body on the transverse vibrations of a spring-mounted circular cylinder (test cylinder) in a uniform flow of low turbulence intensity. Each interfering body is located downstream of the test cylinder. Experiments have been performed with circular and rectangular interfering bodies. The results show that the interference effects on the flow around the test cylinder and on its vibration amplitude depend on the relative dimensions of the test and on the magnitude of the non-dimensional uniform flow velocity. There is a critical combination of non-dimensional velocity, gap spacing and relative dimensions which gives rise to maximum amplitudes of vibration. Flow visualization studies with a stationary test cylinder have provided some explanation of the observed interference effects.