Influence of Stochastic Load Perturbations on the Performance of a Torsional-Flutter Wind Harvester

Wind energy technologies are emerging as the need for clean energy resources has considerably increased in the last decade. Apart from horizontal-axis wind turbines, less efficient at the intermediate scales (or meso-scales) and for moderate wind speeds, a competitive alternative is necessary. This alternative is represented by simpler, smaller-size wind-based energy systems, activated by various aeroelastic phenomena. An ongoing investigation on the performance of an aeroelastic harvester, which can efficiently replace meso-scale wind turbines, is discussed. The apparatus exploits the torsional flutter of a streamlined “rigid” blade that rotates about a pre-set axis through a nonlinear torsional spring mechanism that activates post-critical behavior. A stochastic model of the apparatus, including output power estimation, has been derived to evaluate relevance of uncertain wind loads, induced by imperfect characterization and simplified load assumptions. Studies are carried out to examine mean square stability.