This standalone DWM implementation is currently released only for offshore conditions.
The met data coordinate can be placed anywhere near the wind farm in the current offshore implementation. The correct coordinates for the met data will be needed in a future onshore version.
The turbine coordinate file should be a tab separated text file with ’easting northing’ coordinate pairs on each line.
For information about the turbine data input file see the test data set below. Values for the power curve (Ct, Wind Speed and Power) are written as comma separated values on each row.
The met data file should contain time series with the following tab separated fields (also see the test data set below):
- DateTime = Time stamp as ”YY-mm-dd HH:MM:SS”
- WSP = Wind speed
- WDIR = Wind direction
- TEMP = Temperature
- RHO = Air density
- RI = Richardsson Gradient Number
- WSP.STDDEV = Wind speed standard deviation
Wind speed standard deviation can be left out when using model data, ambient turbulence is then set to the default value of 6%. If using met mast data with wind speed standard deviation, the averaging period should be 10minutes. It is important to keep the header names as above when creating the met data file.
Met data attached in the test data set is a synthesized data set combining model data and Race Bank met mast data for second half of 2006. Race Bank data taken from Marine Data Exchange.
DWM test data: DWM_TEST_DATA_SET
Further information about stability limits
The stability limits are based on Richardsson Gradient Number. The following limits are used:
- RI > 1 : Very Stable
- 0.25 < RI < 1 : Stable to Very Stable (linear interpolation)
- 0.1 < RI < 0.25 : Neutral to Stable (linear interpolation)
- -0.05 < RI < 0.1 : Neutral
- -0.1 < RI < -0.05 : Neutral to Unstable (linear interpolation)
- RI < -0.1 : Unstable