question about aerodyn in open fast v3.5.3

[shipors]

hello ,everyone

I have some questions, please help me，thank you very much! Regarding AeroDyn:

1.Wake/induction model, what is the relationship between this model and the wake model in FAST.Farm?

2.In the V3.0.0 user manual, I saw that aerodynamic calculations within AeroDyn are based on the principles of actuator lines. I would like to ask: in the blade airfoil aerodynamics model, are both the steady model and the Beddoes-Leishman unsteady model based on the principles of actuator lines?

3.In the blade airfoil aerodynamics model, is the steady model based on BEM (Blade Element Momentum)?

4.In the V3.0.0 user manual, there is a statement that says: "While all of the UA models are documented in this manual, the original B-L model is not yet functional." I would like to know if this feature has been implemented in the V3.5.3 version, provided that AFAeroMod is set to 2.

best wishes

[jjonkman]

Dear @shipors,

Here are my responses:

1. When OpenFAST is coupled to FAST.Farm, the AeroDyn module within OpenFAST computes the aerodynamic loads and induction at a given rotor. The aerodynamic loads from each rotor are passed from AeroDyn (through OpenFAST) to FAST.Farm to compute the rotor wakes of each rotor in FAST.Farm.
2. Yes. both the steady airfoil and unsteady airfoil models of AeroDyn can be considered "actuator line" models, as opposed to "actuator disk" or "geometry-resolved" models.
3. The steady airfoil model can be considered the "element" part of the "blade-element/momentum (BEM)" model. The "momentum" part refers to how the induction is calculated, which in AeroDyn can be steady BEM, dynamic BEM, or free-vortex wake (OLAF).
4. The Beddoes-Leishman (B-L) UAMod = 1 model is not currently supported by AeroDyn, but UAMod = 2 (González extension to B-L) and 3 (Minnema/Pierce extension to B-L) are supported.

Best regards,