FAST_v8.15 OutList parameters

Wind & Water Computer-Aided Engineering Software Tools
2

Dear Sarat,

Here are my answers to your questions:

  1. The RtAeroPwr output of AeroDyn v15 is the aerodynamic power captured by the rotor.

  2. Actually, the rotor aerodynamic torque is available in the RtAeroMxh output of AeroDyn v15. But yes, you could derive RtAeroMxh from RtAeroPwr and RtSpeed, as you stated.

  3. The RotPwr output of ElastoDyn is the mechanical power in the low-speed shaft i.e. the reaction torque in the low-speed shaft times its speed. The GenPwr output of ServoDyn is the electrical power output from the generator. Under steady state conditions with 100% gearbox efficiency while producing power, GenPwr would be smaller than RotPwr by the generator electrical-conversion efficiency. But under transient conditions (where the shaft is accelerating or decelerating), the relationship is more complicated.

  4. Under steady state conditions, yes, RotPwr would have the same sign as GenPwr–both are positive when generating power and both are negative when motoring. But under transient conditions (where the shaft is accelerating or decelerating) this need not be true.

For clarification of how the drivetrain model in FAST works, please see the following forum post: Resistant moment of the rotor and of the electric generator.

I hope that helps.

Best regards,