Wake effect on a uniform flow behind wind-turbine model

Wake Conference 2015

Okulov, V.L.^1,2 ; Naumov, I.V.^2 ; Mikkelsen, R.F.^1 ; Sørensen, J.N.^1

Department of Wind Energy, Technical University of Denmark, Lyngby

2800, Denmark^1

Institute of Thermophysics, SB RAS, Novosibirsk

630090, Russia^2

关键词: External disturbances;    Mean velocity profiles;    Regression techniques;    Velocity deficits;    Velocity profiles;    Wake instabilities;    Wind turbine modeling;    Wind turbine wakes;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/625/1/012011/pdf
DOI  :  10.1088/1742-6596/625/1/012011

来源: IOP

【 摘 要 】

LDA experiments were carried out to study the development of mean velocity profiles of the very far wake behind a wind turbine model in a water flume. The model of the rotor is placed in a middle of the flume. The initial flume flow is subjected to a very low turbulence level, limiting the influence of external disturbances on the development of the inherent wake instability. The rotor is three-bladed and designed using Glauert's optimum theory at a tip speed ratio λ = 5 with a constant of the lift coefficient along the span, CL= 0.8. The wake development has been studied in the range of tip speed ratios from 3 to 9, and at different cross-sections from 10 to 100 rotor radii downstream from the rotor. By using regression techniques to fit the velocity profiles it was possible to obtain accurate velocity deficits and estimate length scales of the wake attenuation. The data are compared with different analytical models for wind turbine wakes.