BEMT method in AeroDyn module

Wind & Water Computer-Aided Engineering Software Tools
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Dear @Jason.Jonkman,

Hope you are doing well.
I have some questions regarding AeroDyn module.

  • In AeroDyn standalone version, AeroDyn does not perform aero-elastic calculations right ? Moreover, it does not take .bts file as an input ?

  • In AeroDyn module coupled with OpenFast, when setting WakeMod=1 and SkewMod=1, that means the user chooses to use the uncoupled BEMT. The term uncoupled means that no wake is included while computing aerodynamic loads. In all cases of SkewMod, BEMT performs aeroelastic calculations, right ?

  • In AeroDyn module coupled with OpenFast, it is recommended that the parameter IndToler equals 5e-5 when using OpenFast in single precision. This parameter is the tolerance for the convergence of the residual function, but there is no parameter for the tolerance of the inflow angle nor for the induction factors (axial induction factor, tangential induction factor). My question is what are the tolerances of the latter parameters ?

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Dear @Riad.Elhamoud,

Here are my responses regarding the current version of the standalone driver for AeroDyn:

  • The AeroDyn driver assumed rigid-body kinematics with user-prescribed rigid-body motion (no aero-elastics).
  • The AeroDyn driver does support turbulent inflow when CompInflow is set to 1, in which case InflowWind is coupled to AeroDyn within the standalone AeroDyn driver.
  • The skewed-wake correction model (SkewMod) determines how skew between the inflow and rotor axis is accounted for within BEMT. The difference between “uncoupled” and “coupled” in relation to the skewed-wake correction model is documented in the following BEMT paper: https://www.nrel.gov/docs/fy15osti/63217.pdf.
  • The BEMT implementation in AeroDyn uses a nonlinear solve in terms of the inflow angle, but IndToler represents the tolerance of the nondimensional residual equation, with no physical association possible.

Best regards,

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