Flow-induced vibration of an elastic circular cylinder at sub-critical Reynolds numbers

Two different numerical models are used to examine the flow-induced vibration problem arising from an infinitely long elastic circular cylinder in a uniform cross-flow. These methods are the finite element method and the surface vorticity method. The cylinder motion is modeled by a spring-damper-mass system, and the different time series are analyzed by the ARMA technique. The reduced velocity varies from 3.6 to 9.2, corresponding to a Reynolds number range of 2000 to 5000. This range covers both the resonant and off-resonant case. The purpose of this investigation is to evaluate the relative merits of the numerical models. The surface vorticity method gives a more accurate prediction of the separation points. In spite of this, its predictions of the cylinder dynamics and the fluctuating forces are in substantial disagreement with those obtained from finite element method. Comparison with measurements tends to support the results obtained from the finite element method.