Rapid optimization of stall-regulated wind turbine blades using a frequency-domain method: Part 1, loads analysis


Correspondence: K. O. Merz, Department of Civil and Transport Engineering, Norwegian University of Science and Technology, Høgskoleringen 7A, 7491 Trondheim, Norway.

E-mail: karl.merz@ntnu.no


A fast and effective loads analysis method was developed for the preliminary design of stall-regulated blades. Calculations are conducted in the frequency domain, including a three-dimensional representation of turbulence, for a rapid evaluation of lifetime loads. The structural model is simplified, consisting of a single flexible blade on a rigid drivetrain. Load cases are defined which consider ultimate, extreme operating (with and without tip brake deployment), and lifetime fatigue loads. It is shown, by comparison with time-domain simulations, that the load cases provide a reasonable estimate of design-driving loads. The method described in Part 1 of this article forms the basis for a novel optimization method in Part 2. Copyright © 2014 John Wiley & Sons, Ltd.