Influence of the conservative rotor loads on the near wake of a wind turbine

Wake Conference 2017

Herráez, I.^1 ; Micallef, D.^2 ; Van Kuik, G.A.M.^3

Dept. of Technology, University of Applied Sciences Emden/Leer, Constantiaplatz 4, Emden

26723, Germany^1

Dept. of Environmental Design, Faculty for the Build Environment, University of Malta, Msida MSD

2080, Malta^2

Faculty of Aerospace Engineering, Technical University Delft, Kluyverweg 1, Delft

2629HS, Netherlands^3

关键词: Actuator line technique;    Blade element momentum theory;    Blade-element theory;    Bound vorticities;    Conservative force;    Numerical results;    Quantitative assessments;    Rotor performance;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/854/1/012022/pdf
DOI  :  10.1088/1742-6596/854/1/012022

来源: IOP

【 摘 要 】

The presence of conservative forces on rotor blades is neglected in the blade element theory and all the numerical methods derived from it (like e.g. the blade element momentum theory and the actuator line technique). This might seem a reasonable simplification of the real flow of rotor blades, since conservative loads, by definition, do not contribute to the power conversion. However, conservative loads originating from the chordwise bound vorticity might affect the tip vortex trajectory, as we discussed in a previous work. In that work we also hypothesized that this effect, in turn, could influence the wake induction and correspondingly the rotor performance. In the current work we extend a standard actuator line model in order to account for the conservative loads at the blade tip. This allows to isolate the influence of conservative forces from other effects. The comparison of numerical results with and without conservative loads enables to confirm qualitatively their relevance for the near wake and the rotor performance. However, an accurate quantitative assessment of the effect still remains out of reach due to the inherent uncertainty of the numerical model.