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Wind speed timeseries in .wnd file, what is the influence on the sim results?

Posted: Fri Apr 16, 2021 8:32 am
by Bartosz.Stachowicz
Dear OpenFAST Team,

I have a time-series of mean wind speeds with a single mean direction specified for the whole vector of data, likely output from a wind vane. These mean wind speeds fluctuate quite a bit:
WS.PNG
WS.PNG (118.48 KiB) Viewed 462 times


I have been using these vectors as input to my .wnd files, with some generic sheer, to compare OpenFAST simulations results with some other data parallel to the wind speed time series like platform displacements.
In this case, is the whole field multiplied with the current wind speed from the .wnd file?
will such approach affect the simulation results much?

Reading through the forum I found out there is no way to generate turbsim data driven by a time series.
what can I do?

BS

Re: Wind speed timeseries in .wnd file, what is the influence on the sim results?

Posted: Fri Apr 16, 2021 12:13 pm
by Jason.Jonkman
Dear Bartosz,

By a *.wnd file, presumably you are referring to the InflowWind module's uniform wind file type (WindType = 2). These files are time varying, but spatially uniform (they may include shear). Such files are typically used for deterministic IEC wind cases like gusts and direction changes.

For turbulent inflow, it is better to use TurbSim to generate full-field time- and spatially varying turbulent wind data (WindType = 3 in InflowWind). TurbSim v2.0 and newer (including TurbSim in OpenFAST) does support constrained wind simulation, with the ability to derive the full turbulent wind field based on measured turbulent time series at one or more points. This is known as the TurbMod = TIMESR option in TurbSim, as is discussed in the TurbSim v2.0 documentation and several times on this forum.

Best regards,

Re: Wind speed timeseries in .wnd file, what is the influence on the sim results?

Posted: Sat Apr 17, 2021 10:03 am
by Bartosz.Stachowicz
Dear Jason,

So silly of me! I was sure this was not possible. Thanks to your remarks I have successfully generated files I needed.

thank you,

BS