PhD-defense Kaya Onur Dag

Supervisors: Professor Jens Nørkær Sørensen, Professor Niels N. Sørensen, Professor Wen Zhong Shen

External examiners: Jacob Berg, Associate professor, DTU Wind Energy, Johan Meyers, Associate professor, KU Leuven, Belgium, Matthew J. Churchfield, Senior Engineer, NREL, USA

Abstract: Combined pseudo-spectral / actuator line model for wind turbine applications

 The dissertation deals with the development of a combined pseudo-spectral Navier-Stokes/actuator-line code for large eddy simulations (LES) of flows about wind turbines and in wind farms. A main part of the work has been to develop a scalable and efficient flow solver which is capable of providing reliable loads and performance computations of wind turbines subject to turbulent inflow.

The accuracy of the code was verified by comparison to direct numerical simulations of a turbulent channel flow and the scalability the code was verified by checking the relative speed-up on different grids. Both tests gave very promising results.

Another part of the work concerned the improvement of the actuator line methodology in which a novel technique for correcting the loading on the blades was introduced and tested. Using this technique it is now possible to perform high-accuracy computations at relatively course resolutions of the blade loading, hence increasing both accuracy and computational efficiency. The new technique was successfully tested on a planar wing as well as on the NREL 5MW reference rotor and on the NREL phase VI rotor, and it was found that high-accuracy results could be obtained using grid resolutions as coarse as 10 grid points per blade.


tir 20 jun 17
14:00 - 16:00


DTU Vindenergi


Technical University of Denmark
DTU Lyngby Campus, building 306, Auditorium 31
2800 Lyngby