Environmental Engineering Reference
In-Depth Information
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Time (s)
Figure 3: Displacement time-history at the top of the tower ignoring blade rotation.
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Frequency (rads -1 )
Figure 4 : Fourier transform amplitude of wind velocity.
the blades masses are lumped on the top of the tower thus, ignoring the tower-blade
interaction. The maximum observed tower tip response is 0.108 m.
The forced vibration response of the coupled tower-blade model is also calcu-
lated for a rotational frequency of 1.57 rad/s. Figure 4 presents a Fourier transform
of the simulated fl uctuating wind velocity acting at the tip of the blade. An increase
in energy is clearly observable at integer products of the rotational frequency.
Figure 5 illustrates the computed blade tip displacement time-history. The maxi-
mum observed displacement is approximately 0.75 m. Figure 6 presents the total
 
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