search

OpenFAST / openfast

Main repository for the NREL-supported OpenFAST whole-turbine and FAST.Farm wind farm simulation codes.
http://openfast.readthedocs.io
Apache License 2.0
654 stars 447 forks source link

LSSTipMza at different yaw angle input #2066

Open opendiego opened 4 months ago

opendiego commented 4 months ago

Good morning, I am conducting analyses on the yaw behavior of turbines and I had to calculate the values of lateral force 'LSShftFya' and moment 'LSSTipMza' for different yaw angles, setting these as initial conditions in the elastodyn file. Additionally, to calculate these values, I had to set the yaw control section to 'False'.

Upon plotting the trends, I noticed that for wind speeds lower than the rated speed, the moment Mz tends to realign the turbine with the wind. However, for wind speeds higher than the rated speed, the moment becomes destabilizing. At low angles of misalignment, it tends to deviate from the orthogonal condition with respect to the wind. Could you kindly explain the reason behind this behavior?

I thank you in advance. Best regards, Diego Piergentili

jjonkman commented 4 months ago

Dear @opendiego,

The azimuth "a" coordinate system of ElastoDyn spins with the rotor, so, I would expect it would be difficult to see the influence on yaw with outputs LSShftFya and LSSTipMza. Do you mean LSShftFys and LSSTipMzs, which don't spin with the rotor?

Best regards,