Time and Frequency Domain Analysis of Wind Turbine Towers Under Spatially Correlated Wind Field

摘要

This work proposes a methodology to evaluate the dynamic behavior of Wind Turbine Towers (WTT) taking into account the effects of wind on its structural components (tower, nacelle, and blades). A model to generate wind velocity signals that are correlated in time and space is adopted, following a usual von Kármán Power Spectral Density (PSD) which has parameters such as turbulence intensities and standard deviations of the wind speed fluctuations in the three directions, velocity profile with height, and decay coefficients of the coherence with the distance between the points of simulation. It is investigated whether the time domain (TD) or frequency domain (FD) analysis is adequate in terms of simulation time, accuracy and computational costs for the evaluation of RMS values of acceleration and displacement signals at specific points of the WTT as well as base reactions. In FD the direct integration of specific PSD (displacements, accelerations, etc.) is employed. Results for a typical simulation are investigated and compared in different situations of wind speed and wind parameters for the simulation of the dynamic behavior of the WTT. The results present the importance of the spatial simulation of wind velocity correlation to account for important final structural behavior.