Equivalent oscillator approach to model vortex induced vibrations on a circular cylinder

The paper presents a numerical model, based on the equivalent oscillator approach, able to simulate vortex induced vibrations on a circular cylinder. This model consists of a single degree of freedom mechanical system characterized by non-linear parameters that reproduce the fluid -structure interaction in time domain. A genetic algorithm approach was used in order to iden-tify the characteristic parameters of the equivalent oscillator: obtained results are discussed and compared with wind tunnel experimental data and with a previous version of the numerical model. Comparison is performed both in terms of aerodynamic forces and oscillation amplitudes and both in steady and transient conditions.