I am trying to replace AeroDyn by my own aerodynamic code in FAST (v8.15).
The coupling between my aero module and FAST is based on what is done for AeroDyn.
Here is my problem.
It seems that there is an issue during the interpolation step, when loads are transferred from the output Line2 mesh of the aero module to the input Point mesh of ElastoDyn. Indeed, some oscillations appear in the input mesh of ED when I plot forces along the span, while they were not present in the output mesh of the aero module (cf. attached graph below, where spanwise forces per unit length in z direction on blade 1, at a given time of the simulation, are plotted on the output mesh of the aero module and the input mesh of ED, with different number of nodes).
Here I run a very simple simulation, only ED and my aero module are enabled (the wind is set by my aero module as well).
I have a mesh with variable spacing between the nodes for the output mesh of the aero module and constant spacing for ED, but I have the same problem with constant spacing for the aero output mesh. I have also similar oscillations when I use AeroDyn instead of my aero code.
Have you noticed this issue before ? Are these oscillations expected when using the “transfer_line2_to_point” routine ?
If yes, could they have consequences on the deformation of the blades or on the global behavior of the wind turbine ?
Thank you. Best regards,