Environmental Engineering Reference
In-Depth Information
Figure 8-33. Pattern of generated turbulence in the wake of an operating 200-kW Mod-
OA HAWT, two rotor diameters downwind.
Changes from the ambient turbulence are
noted at each anemometer location. [Connell and George 1982]
Methods of simulating turbulence can be grouped into three generic techniques:
transformation, correlation
,
and
harmonic series.
Simulated turbulence signals are
frequently superimposed on a signal representing the steady, non-uniform wind field to give
the instantaneous wind.
Transformation Techniques
In the transformation technique a
Gaussian white noise signal
is passed through a filter
or series of filters, as illustrated in Figure 8-34. The filters tailor the input signal so that
the output signal has the statistical properties of the wind field being simulated. The
number of statistical properties which are matched depends on the sophistication of the
filtering system. In the simple system shown in Figure 8-34(a), the one-dimensional wind
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