TurbSim - Specify Wind Speed and turbulence statistics from t = 300s

1

Hi everyone,

I have been playing around with openfast lately and have stumbled upon a problem for which I have not found an answer on this forum hence my post (apologies in advance if this has already been posted though…).
I would like to generate a 3,900s time series, the first 300s of which I would not considered in the post-processing part due to transients. For the last 3,600s, I would like to have a specific average wind speed (say 10m/s) at hub height and a specific turbulence intensity (say 6%).
At the moment, my understanding is that we can only specify the mean wind speed and turbulence intensity for the whole duration of the Turbsim file (e.g. 3,900s rather than 3,600s).
I think I have found a workaround by running 7,200s and throwing the first 3,600s but this is quite a loss of resources…
Would anyone have a more elegant solution to this problem?
Thanks in advance,
Bruno Nguyen.

2

Dear @Bruno.Nguyen,

The more elegant solution is to generate a turbulent wind data file that is 3600-s long and periodic in time. You can then run a 3900-s simulation in OpenFAST and the wind over the last 300 s will be a repeat of the wind over the first 300 s. You can generate periodic wind data in TurbSim by setting UsableTime = “ALL” (and in your case AnalysisTime = 3600 s).

Best regards,

3

Dear Jason,

Thanks for the swift and helpful answer. I had not realised that the TurbSim timeseries was continuous at t=0 and t=t_end.
Have a nice day!
bruno