Impact of modeling approach on flutter predictions for very large wind turbine blade designs

Recent predictions for very large wind turbine blades have indicated that flutter may be a significant concern. Indeed, previous predictions showed a decreasing flutter margin (ratio of flutter speed to operating speed) with an increase in blade length. Previous flutter predictions were performed with a NASTRAN based flutter prediction tool that was originally developed for vertical-axis wind turbine blades. Recently, a new flutter prediction tool has been developed using a custom finite element framework. This new tool has the capability to provide a better geometric representation of a blade and also provides automated algorithms to perform iterative flutter calculations. In the course of applying the newly developed tool to very large blade designs, potential issues with modeling approaches were identified. The choice of aeroelastic representation for flutter analysis of very large wind turbine blades was reevaluated, and revised flutter analysis under different representations shows different flutter predictions for very large blade designs. 2013 by the American Helicopter Society International, Inc.

Impact of modeling approach on flutter predictions for very large wind turbine blade designs Conference Paper