Comparison between experiments and Large-Eddy Simulations of tip spiral structure and geometry

Wake Conference 2015

Ivanell, S.^1,2 ; Leweke, T.^3 ; Sarmast, S.^1 ; Quaranta, H.U.^3 ; Mikkelsen, R.F.^4 ; Sørensen, J.N.^1,4

Uppsala University, Wind Energy Section, Campus Gotland, Visby

621 67, Sweden^1

KTH Mechanics, Stockholm

100 44, Sweden^2

IRPHE, CNRS, Aix-Marseille Université, Centrale Marseille, Marseille

13384, France^3

Wind Energy Department, Technical University of Denmark, Lyngby

2800, Denmark^4

关键词: Actuator line technique;    Aerofoil characteristics;    Experimental uncertainty;    Helical vortices;    Numerical results;    Spiral structures;    Stability parameters;    Wake expansions;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/625/1/012018/pdf
DOI  :  10.1088/1742-6596/625/1/012018

来源: IOP

【 摘 要 】

Results from Large-Eddy Simulations using the actuator line technique have been validated against experimental results. The experimental rotor wake, which forms the basis for the comparison, was studied in a recirculating free-surface water channel, where a helical vortex was generated by a single-bladed rotor mounted on a shaft. An investigation of how the experimental blade geometry and aerofoil characteristics affect the results was performed. Based on this, an adjustment of the pitch setting was introduced, which is still well within the limits of the experimental uncertainty. Excellent agreement between the experimental and the numerical results was achieved concerning the circulation, wake expansion and pitch of the helical tip vortex. A disagreement was found regarding the root vortex position and the axial velocity along the centre line of the tip vortex. This work establishes a good base for further studies of more fundamental stability parameters of helical rotor wakes.