Page 164 - Wind Energy Handbook
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138 AERODYNAMICS OF HORIZONTAL-AXIS WIND TURBINES
3.11.7 Comparison of methods
A project to compare existing methods of predicting yaw behaviour, among other
aspects of the aerodynamic behaviour of wind turbines, was reported upon (Snel
and Schepers, 1995). Figure 3.73 shows results obtained by various methods for
predicting the yawing moment of the 2 MW, three-blade turbine at Tjæreborg in
Denmark at a yaw angle of 328 and a wind speed of 8:5m=s.
Most of the theoretical predictions in Figure 3.73 have the correct phasing and
about the correct mean yawing moment but the amplitude of the yawing moment
varies. In this example the second method bears the closest comparison with the
measured data. Generally, the amplitude of the yawing moment variation is under-
estimated by the theoretical predictions, whereas the mean yawing moment is quite
well predicted.
0
-50
Yawing moment (kNm) -100
-150
-200
0 90 180 270 360
Azimuth angle in degree
ECN.i.w. Vortex cylinder method
ECN.d.e. Method using eqn. 3.173 to determine F(µ)
GH Pitt and Peters eqn. 3.189
Unist CFD method
NTUA CFD method
TUD Method using eqn. 3.123
TA CFD method
meas. Measured data
Figure 3.73 Yawing Moment on the Tjæreborg Turbine at 328 Yaw and 8.5 m/s, (Srel and
Schepers 1995)
