Research on influence of ice-induced vibration on offshore wind turbines

Abstract

This paper presents the simulation of offshore wind turbines (OWTs) suffering from turbulent wind and ice-induced vibrations (IIVs). To ascertain the effectiveness of IIVs, the fully coupled simulation of the NREL 5 MW OWT is implemented. The OWT model, which is processed as a multibody system, takes the aerodynamic load and the IIV simultaneously. Firstly, the Kaimal spectrum is used to simulate the turbulent wind conditions. Then, the aerodynamic load acting on the blades is solved by the blade momentum theory. The IIV can be explained as the forced vibration or the self-excited vibration. The Matlock model and the Määttänen model are employed here to solve the forced ice-induced vibration and the self-excited ice-induced vibration, respectively. Finally, the kinetics and the kinematic computation are coupled with aerodynamic load calculations. The dynamic responses of some crucial parts of the OWT model reveal some important results. The results prove the great effectiveness of IIVs impacting the OWTs, especially for the tower. The frequency-domain responses note that the IIV affects the particular frequencies remarkably.