On the maximum amplitude for a freely vibrating cylinder in cross-flow

Abstract: The response of a freely oscillating circular cylinder (“free vibration”) in cross-flow has been studied experimentally using controlled magnetic eddy current to provide variable damping. In general, the nondimensional response amplitude, A*, and dominant frequency, ω*, depend on the Reynolds number, Re, and the nondimensional mass, m*, damping, b*, and elasticity, k*, of the system. The main objective of this study is to characterize the maximum amplitude that is achieved for a given system as cross-flow velocity is varied. We find that this maximum amplitude, , occurs within a small range of values of . For values of Reynolds number in the range 525<Re<2600, we determine for lightly to moderately damped systems. Extrapolating these results to b *=0 defines limiting values of amplitude, , which depend on Reynolds number. An important point is that these results do not depend on the specific value of either m* or k*. These results show that the Reynolds number, which has generally been ignored in discussions of maximum-amplitude data, is an important parameter. [Copyright &y& Elsevier]