Interference effects on the flow-induced vibrations of a circular cylinder in side-by-side and staggered arrangement

This paper presents the results of an investigation on the interference effects of a rigid circular cyclinder on the transverse vibrations of a spring-mounted circular cylinder (test cylinder) exposed to a uniform flow. All tests were at a single value of the reduced velocity, viz., 7·0. The interference effects were studied for the side-by-side arrangement and staggered arrangement. Experiments have been carried out for various relative dimensions of the test cylinder and the interfering cylinder; the tests for the staggered arrangement were conducted for several gap widths between the two. The results indicate that there is a critical combination of relative dimensions and spacing which gives rise to maximum amplitudes of vibration. A tentative explanation is offered for the observed features based on flow-visualization studies. © 1988 Academic Press Limited.