Blade pitch angle for below cut in wind speeds

Wind & Water Computer-Aided Engineering Software Tools
1

Dear @Jason.Jonkman,

Hope you are doing well. I am running several load cases for a specific site using OpenFAST. The wind rose of this site contains some wind speeds that are below cut-in and they have a significant probability of occurence (around 10%).

I have some questions regarding the OpenFAST simulations:

  • According to AeroDyn manual, the parameters WakeMod and AFAeroMod in AeroDyn 15 input file should be : WakeMode=0 and AFAeroMod=1. Right ?
  • The blade pitch controller shoule be turned on. Right ? I mean blade pitch angle at the beginning of the simulation that generally we set in order to avoid tower strike.
  • What about the blade pitch angles ? Do you think they should be 90 degrees or 0 degree ?

Thank you in advance,

Best Regards,

Riad

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Dear @Riad.Elhamoud,

Below cut-in wind speed, I would expect a modern utility-scale wind turbine rotor to be idling with the blades feathered and the nacelle yaw generally aligned with the wind direction. So, I would set WakeMod = 0 and AFAeroMod = 1 in AeroDyn, set RotSpeed = 0 rpm and BlPitch = 90 deg in ElastoDyn, and disable pitch control and torque control in ServoDyn (PCMode = 0, GenTiStr = TRUE with TimGenOn set greater than TMax).

Best regards,

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