Automatic generation of TurbSim bts files with UsableTime "ALL"

[mcollu]

Description of feature

Hi, I was wondering if the following option is available and, if not, if it could be implemented.

I need to run 1-hour long OpenFAST simulations (simulated time), for DLC 1.6.
WEIS automatically generates bts files with 1-hour worth of wind speeds.

What I would like instead is the generation of 600 seconds bts files, with the TurbSim input option:
"ALL" UsableTime

Potential solution

In WEIS modeling schema the UsableTime can be set to all as:

    DLCs:
      - DLC: '1.6'
        analysis_time: 3600   #600
        transient_time: 600
        turbulent_wind:
            UsableTime: "ALL"

but there does not seem to be an option to set up AnalysisTime.

I tried, as per the following, but it is ignored, taking as AnalysisTime the "analysis_time" of the DLC

      - DLC: '1.6'   # With the new WEIS release, to be substituted by "Steady"
        analysis_time: 3600   #600
        transient_time: 600
        turbulent_wind:
            AnalysisTime: 600
            UsableTime: ALL

[dzalkind]

Hi Maurizio,

I believe UsableTime is ALL by default, so no need for that option.

If you don't want any transient time, transient_time: 0 is possible.

AnalysisTime in turbsim will be analysis_time + transient_time for that case.

Please let us know if you need anything clarified further.

Best, Dan

[mcollu]

Thanks, @dzalkind

So, I suppose it is not possible to set a Turbsim AnalysisTime shorter than the OpenFAST AnalysisTime?

I would like WEIS to generate a 10 minutes Turbsim bts file, which is repeated 6 times in OpenFAST when simulating 1 hour, for example, rather than generating a 60 minutes Turbsim file.

[dzalkind]

Hi Maurizio,

I'm sure that is possible with a little development effort, but I'm not sure it's possible by only changing the input files at this time. I'll think about how that could be supported and keep you posted.

Best, Dan

[mcollu]

Thanks, @dzalkind

Sure, no problem.
The reason I am asking is because is explicitly mentioned in the IEC-61400-3-x standards as acceptable, and it would save a bit of space generating 10min rather than 1hour or 3hours TurbSim time signals.

[dzalkind]

Ah, I see. Our typical approach is to set n_seeds: 6 (or 18) and let the parallelization of WEIS generate 6 turbsim files.

DLC_driver:
    DLCs:
        - DLC: "1.1"
          ws_bin_size: 10
          n_seeds: 6
          analysis_time: 0.1
          transient_time: 0.

[mcollu]

Not sure I understood.
If I have an analysis_time: 3600, and I specify n_seeds: 6, automatically WEIS will generate 6 3600s turbsim files or 6 600s turbsim files?

[dzalkind]

If I have an analysis_time: 3600, and I specify n_seeds: 6, automatically WEIS will generate 6 3600s turbsim files or 6 600s turbsim files?

This will create 6 3600s turbsim files.