Dear all,
as I would like to use the same Bladed-Style Kaimal wind files with different turbulences I need to adjust the corresponding *.sum files every time.
As there can only be one corresponding .sum file for the wind files (.wnd) this would lead to doublings for the wind files and therefore a lot of disk space.
Apart from coping the wind files in a different folder and change the *.sum files there, there are some ideas to improve this problem:
- include setting that are taken from the *.sum file in the Inflow-File.
- link the wind file in the *.sum file so that the same wind file can be used with different Ti at the same time. (consequently only the *.sum file would be linked in Inflow)
- Link the *.sum and *.wnd file independent from each other in Inflow.
Is there another option that I’m not aware of?
Could one of these ideas implemented in a future release?
Shall I post this issue on github?
Best regards,
Simon
Dear Simon,
If I understand what you want to do is be able to scale the turbulence intensity stored within the wind data (wnd) file by changing only the summary (.sum) file. Is that correct?
This is not really possible with TurbSim-generated wind data files because the binary files not only store the variations of wind about the mean, but the wind data files store the mean wind profile (including shear and veer) as well. TurbSim functions this way because many of the turbulence models built within TurbSim (except for the simpler IEC models) derive the local turbulence from the local wind speed based on the profile (unlike the simpler IEC models available in Bladed and other software that assume the turbulence depends only on the hub-height wind speed and so can be derived independently from the mean wind profile).
A few comments:
- The *.wnd files generated by TurbSim use the same binary format as those generated by Bladed, but TurbSim includes the mean wind profile in the .wnd file unlike the wind files generated directly within Bladed. The *.sum file is needed in the InflowWind module of FAST to properly interpret the data stored in the *wnd file.
- The *.bts files generated by TurbSim use a different binary format that stores all of the information InflowWind needs to interpret the data stored within it. Again, the mean wind profile is included along withe variations about the mean.
- InflowWind can also use HAWC-formatted files e.g. as derived from the Mann turbulence simulator. This binary format does not include the mean wind profile in the data. So, InflowWind has an option to add the mean wind profile and to scale the wind variations to match a given desired turbulence intensity. It sounds like this is the feature you want. So, you may wish to use a Mann turbulence simulator together with FAST/InflowWind rather than using TurbSim.
- I’m sure InflowWind could be modified so that it is possible to use Bladed-formatted wind (*.wnd) files that don’t have the mean wind profile included (such that the mean wind profile and scaling could be applied within InflowWind), but TurbSim would then also have to be modified to produce wind data files in this format. Again, this was not done originally because many of the turbulence models within TurbSim base the turbulence on the mean wind profile.
Best regards,
Dear Jason,
yes, you got me right. I would like to modify the turbulence of existing wind files. These are generated by TurbSim OR by Bladed.
With a simple test I was able to change the Ti with the *.sum file for a bladed generated wind file. In the summary of Inflow the correct TI was printed. Is that a prove, that this TI from the *.sum file has been used in the simulation?
Regarding the mean wind profile (e.g. sheer):
I assume, that when using a bladed generated wind file Inflow assumes a constant wind profile because no profile is given by bladed. Is that correct?
So to used different mean wind profiles one would need to create different wind files with TurbSim?
Till now other wind file formats are to an option. Are there validations available between HAWC-formatted files from TurbSim and Bladed style files from TurbSim?
Best regards,
Simon
Dear Simon,
You can change the TI by scaling the TI in the *.sum file, but if the corresponding *.wnd file has shear, the scaling will impact the shear.
If you use Bladed to generate the *.wnd file, Bladed will include the mean hub-height wind speed in the file, but will not include the shear. The InflowWind module of FAST will not add shear to the file, so, using a Bladed-generated wind file means that the FAST simulation will not have shear. So, I’d recommend using TurbSim rather than Bladed to generate wind data for FAST.
I’m not sure I understand your last question about validation. TurbSim doesn’t currently generate HAWC-formatted files.
Best regards,