Numerical simulation of vortex-induced vibration on 2D circular cylinders

By combining the sliding mesh and dynamic layering model and by embedding Newmark-β codes for solving structural dynamics into FLUENT through the interface User Define Function,this paper presents a VIV-simulation model.Reynolds numbers are assumed in the range of 6×103～2×104,and the corresponding reduced velocities(Vr(Vr=U/fNwaterD,where U is the velocity of inflow,fNwater is the natural frequency of structure in water, D is the diameter of circular cylinder) vary from 3 to 10.k-ω SST(shear-stress-transport) model is applied to take the turbulence into account at large Re number.For a initially resting circular cylinder at each computational case,four groups of cases(nondimensional mass m=12.8,255.5 and structural damping ratio =0.0%,0.5%) are computed,and it is found by comparing the classical Feng-type plots that the "initial" branch and the max of amplitude A within lock-in range in this study collapse well with the experimental data at low combined parameter m,and the "jump" phenomena between the "initial" and "lower" branches are observed.Moreover,two groups of cases are computed,and the results reveal that the relation between and A is nonlinear,but that between and A is nearly linear.