Early Concept Evaluation of Floating Vertical Axis Wind Turbines: Method development and testing utilizing FE-modelling, structural optimization and H-rotor designs
Typ
Examensarbete för masterexamen
Program
Product development (MPPDE), MSc
Publicerad
2022
Författare
Arvidsson, Karl
Bergström, Rebecka
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
This master thesis concerned constructing a method for evaluation of concepts of
floating vertical axis wind turbines, FVAWT, with an H-rotor design at an early
design phase. As optimization is used, further sub-concepts are also generated and
evaluated. Furthermore, the method was utilized on two models for a 1 MW and
10 MW turbine. The project was conducted together with the company SeaTwirl.
Their current turbine design was used to build the initial models. FE-modelling
and optimization were performed in Ansys workbench. The focus was on structural
modeling and optimization, with aerodynamic, gravitational, and centrifugal loads
being the ones considered. The studied part of the FVAWT was the rotor, consisting
of two struts per blade, three blades, and a tower. These parts were optimized with
respect to cost by creating a goal function dependent on the mass and the vertical
center of gravity. The considered structural constraints were the first eigenfrequency,
fatigue of the tower, and the ultimate limit state, ULS, on blades and struts in form
of maximum allowed strains. To facilitate the optimization, assumptions to simplify
the model and reduce the number of parameters were introduced. The project
resulted in a method considered feasible to obtain indications of an optimal design
for a floating vertical axis wind turbine of H-rotor design. Possible designs for a 1
MW and a 10 MW rotor were also found by utilizing the developed method.