In the past 25 years various investigations of wind turbine aerodynamics have been performed in wind tunnels (see e.g. Ronsten et al. , Vermeer , Schreck et al. [al]). Compared to full-scale field measurements, experiments performed in wind tunnels take place under controlled operating conditions where the on-set flow is uniform and well-defined. However, if realistic information are to be achieved it is absolutely necessary that the model parameters, i.e.Reynolds and Mach numbers, are close to the ones that are met in practice. This demands that the size of the model rotor are not too small, since important properties of the blade boundary layer otherwise cannot be captured correctly. On the other hand, severe problems with wind tunnel blockage may be the result if the ratio between the areas of the rotor and the wind tunnel cross section is too big. In all cases, wind tunnel wallcorrections are needed in order that measured data corresponds to unconstrained flow conditions. The present work is based on a model for ducted axial fans by Sørensen and Sørensen , modified to account for free (unbounded) turbines . Here, we extend the model to acount for wind turbines placed in wind tunnels with finite gap between the tip of the rotor and the tunnel walls.
|Title of host publication||Proc. European Wind Energy Conference & Exhibition|
|Editors||- European Wind Energy Association|
|Place of Publication||CD-ROM, www.ewea.org|
|Publisher||European Wind Energy Association (EWEA)|
|Publication status||Published - 2003|
|Event||2003 European Wind Energy Conference and Exhibition - Madrid, Spain|
Duration: 16 Jun 2003 → 19 Jun 2003
|Workshop||2003 European Wind Energy Conference and Exhibition|
|Period||16/06/2003 → 19/06/2003|
Sørensen, J. N., & Sørensen, D. N. (2003). Blade-Element/Momentum Technique for Rotors operating in Wind Tunnels. In . European Wind Energy Association (Ed.), Proc. European Wind Energy Conference & Exhibition European Wind Energy Association (EWEA).