Unsteady and non-linear aeroelastic analysis of large horizontal-axis wind turbines

Abstract

Analysis results, obtained from numerical simulation, for non-linear and unsteady aeroelastic behavior of large horizontal-axis wind turbines are presented in this paper. Simulations are carried out using a partitioned scheme of weak interaction that allows dealing with the fluid–structure interaction problem by using one method to solve the structural-dynamic problem and another method for the aerodynamic problem. The aerodynamic model used is the non-linear, unsteady vortex lattice method (NLUVLM). The structural model used is a system of beam finite elements and rigid bodies with finite rotation. This provides a very general tool with relatively low computational cost. The proposed method allows predicting from the operating conditions (wind speed and direction, pitch angle of blades, etc.) the aeroelastic response of wind turbines, characterized by variables such as rotation speed of the rotor, loads on the structural components and the extracted power, among others.