a new user to FAST here.
If I set GenDOF to FALSE and then define the the rotor speed, what torque is applied to the rotor shaft (besides the aerodynamic torque), if any at all?
I have taken the SWRT Burgey style model and switched the GenDOF to False, then set the rotor speed to 25 and had a wind input file running from 1 m/s to 18 m/s over 1500 seconds. I then repeated this for 50 rpm, 75 rpm etc. with the intention of creating a family of torque and power curves which would then allow me to plot a surface plot.
I am using RotTroq and Rotpwr which I have verified against RotCq 0.51.225windspeed^2swept arearadius and RotCp 0.512…5windspeed^3swept arearadius.
I changed the torque on the torque speed look up table written by KP and this had no effeect on the performance characteristics of the model leading me to conclude that when GenDOF is False, there is no torque applied to the rotor shaft by the generator. Therefore the RotCq and RotCp values I am using are a direct reflection of the rotor characteristics when unloaded.
Any comments on this would be greatly appreciated. I am also willing to accept that I have a weak grasp of this and am barking up the wrong tree.