Wake and wind farm modelling. Part B: Wake gust modelling
report
The Department of Fluid Dynamics of TNO Environmental and Energy
Research has coordinated the CEC JOULE project Wake and Wind Farm Modelling.
The project resulted in:
— two modular wind farm codes;
- the gust model WAKEGUST.
The wind farm codes are described in part A of the project report. WAKEGUST is
described in this part (part B) of the project report.
WAKEGUST enables wind turbine designers to compute loads on wind turbines in
homogeneous terrain, and in a single wake of a wind turbine. WAKEGUST describes
the gust amplitude and the gust duration in non-dimensional parameters. The first
parameter is normalized by dividing the amplitude with the corresponding rms value,
the second parameter is normalized by dividing the duration by the mean gust
duration.
WAKEGUST has been based on existing gust models of CSTB (France) and TNO
(The Netherlands). These models have been developed for stand-alone wind
turbines. The new gust model has been validated using time series of wind
measurements collected at several points inside and outside the Dutch experimental
wind farm at Sexbierum. The measurements inside the farm have been restricted to
single wake cases at distances between 2.5 and 8D behind the upstream wind turbine.
Comparisons between the calculations and the measurements of both the u- and the
v-component ofthe wind speed show very good results. The agreement decreases for
increasing values of the gust parameters, i.e. the normalized amplitude and the
normalized duration. This is most likely a statistical effect due to the decreasing
number of gusts with large amplitude and/or with large duration.
Research has coordinated the CEC JOULE project Wake and Wind Farm Modelling.
The project resulted in:
— two modular wind farm codes;
- the gust model WAKEGUST.
The wind farm codes are described in part A of the project report. WAKEGUST is
described in this part (part B) of the project report.
WAKEGUST enables wind turbine designers to compute loads on wind turbines in
homogeneous terrain, and in a single wake of a wind turbine. WAKEGUST describes
the gust amplitude and the gust duration in non-dimensional parameters. The first
parameter is normalized by dividing the amplitude with the corresponding rms value,
the second parameter is normalized by dividing the duration by the mean gust
duration.
WAKEGUST has been based on existing gust models of CSTB (France) and TNO
(The Netherlands). These models have been developed for stand-alone wind
turbines. The new gust model has been validated using time series of wind
measurements collected at several points inside and outside the Dutch experimental
wind farm at Sexbierum. The measurements inside the farm have been restricted to
single wake cases at distances between 2.5 and 8D behind the upstream wind turbine.
Comparisons between the calculations and the measurements of both the u- and the
v-component ofthe wind speed show very good results. The agreement decreases for
increasing values of the gust parameters, i.e. the normalized amplitude and the
normalized duration. This is most likely a statistical effect due to the decreasing
number of gusts with large amplitude and/or with large duration.
Topics
TNO Identifier
253586
Publisher
TNO
Collation
159 p.
Place of publication
Apeldoorn