Hi,

I need clarifications regarding the computational differences using ElastoDyn+AeroDyn_v15 and ElastoDyn+AeroDyn_v15+BeamDyn. I’m not understanding the differences occurred in the steady state values of the collective pitch u[/u] considering an isotropic blade modelled throught FAST with same mechanical properties using BeamDyn and ElastoDyn respectively. In particular, the simulation is performed using FAST+Simulink considering a steady wind with wind speed equal to 18 m/s, the turbine implied is a RWT 10MW DTU, the control strategy is based on collective pitch controller and torque controller; constant power output is the goal of the control strategy.

My personal guess about the explanation of the pitch difference between ED+ADv_14 and ED+ADv_15 model is that the modellation with ADv_14 and ADv_15 is not perfectly equal and the difference between the two might rise difference in output. This explanation doesn’t fit if we consider ED+BD+ADv15 and ED+ADv15, since I’m modelling the mechanical properties equally in both cases and the AeroDyn model is the same.

In particular the pitch difference is about 0.5 deg considering ED+BD+ADv15 and ED+ADv15.

I hope that someone could give me a more solid explanation to this situation.

Thanks in advance for your help.

Simone