The Influence of Geometrical and Structural Properties of Wind Turbine Blades on Blade Bearings

The Influence of Geometrical and Structural Properties of Wind Turbine Blades on Blade Bearings

Baust, Sebastian (TU Delft Aerospace Engineering)

Teuwen, Julie J.E. (mentor)

Delft University of Technology

Aerospace Engineering

2019-08-20

In this thesis the influence of the geometrical and structural rotor blade properties on the pitch bearing loads and deformations is investigated by developing a scalable finite element rotor blade model in Ansys Classic and analyzing the impact of different blade designs. The research aim of this thesis is to determine blade properties which are critical for the bearing design, so these critical parameter can be considered by blade designer in future blade
designs to improve the performance of the pitch bearings. For this purpose the research question is, which rotor blade parameter have a significant impact on the bearing and which blade designs are favourable for the loads and deformations of the bearing.

To answer the research question, this thesis investigates several blade properties, including the number and position of the shear webs, the width and arrangement of the spar caps, and the overall bending stiffness of the blade. The author hypothesizes, that the shear web and spar cap configurations of different blades have a significant influence on the rolling element forces and deformations of the bearing. This assumption applies especially to flapwise loads. For edgewise loads no significant influences are expected.

For the investigation many blades with different properties are needed. For this purpose, this thesis presents one method of developing a scalable rotor blade model, which is used to efficiently design many blades with different shear web and spar cap configurations, and different bending stiffnesses. The different blades are then assembled to the bearing for the parameter study. To perform the study as close as possible to reality, support structures like a wind turbine rotor hub and a stiffener plate on the bearing are also considered.

The results reveal, that neither the shear web configuration, nor the spar cap configuration have a considerable influence on the bearing loads and deformations. The results contradict the hypotheses of the author and suggest, that it does not make sense to include the bearing characteristics in the blade design process. However, to verify this conclusion, future work is necessary, as some phenomena present in current blade model can not be explained conclusively.

http://resolver.tudelft.nl/uuid:8161421d-c86e-4a9a-b768-1b4fd3a1797b

Student theses

master thesis

© 2019 Sebastian Baust