Incorporation of subcritical Reynolds number into an aerodynamic damping model for vortex-induced vibration of a smooth circular cylinder

Abstract

Vortex-induced vibration (VIV) of a circular cylinder is known to be affected by the Reynolds number, while this effect has rarely been considered in VIV modeling. This paper attempts to incorporate the Reynolds number into an aerodynamic damping model for simulating the VIV of a circular cylinder with a smooth surface immersed in a smooth flow. Aerodynamic damping parameters within the Reynolds number range of 500 ∼ 33000 (i.e., the TrSL1 and TrSL2 regimes) are identified according to the griffin plots and existing forced vibration experimental data. The model can simulate the peak VIV amplitudes of an elastically supported rigid circular cylinder at different mass-damping parameters in the TrSL1 and TrSL2 regimes. Both experimental results and numerical simulations demonstrate that the peak VIV amplitude of a low-damping cylinder is highly dependent on the Reynolds number, while the dependency is decreased by increasing the mass-damping parameter. The results suggest that the Reynolds number effect is significant in the VIV analysis of a lightly damped cylindrical structure, while the role of Reynolds number seems insignificant for a moderate-damping or high-damping cylindrical structure. For a flexible circular cylinder, the proposed model is expected to predict slightly higher peak VIV amplitudes because the aerodynamic damping effects are overestimated at some segments along its length.