Wind turbine installation analysis

Good evening,

I’m trying to analyze the forces that could appear during the installation of a three bladed wind turbine in Fast v7. For that, I’ve tried to make a model with just one blade and another one with two but with 120 degrees between them.

In the first try, I specified just one blade file (blade.dat) in the slots of the primary file (.fst). In this case, when I tried to run Fast appeared an error explaining that I have to specify the three files to continue.

On the second try, I specified the three blades but I tried to despise one of them decreasing its mass a lot. In this case, the issue was that appears to be a mathematical problem, because the program reports that there are some blade elements in supersonic or just doesn’t report any valid value (NaN results).

My question is, is there any way to analyze a wind turbine during its installation? (first at all with just the tower, secondly one blade in different positions and finally two blades)

Thank you in advance,


Dear Marcos,

Good question. You shouldn’t have any problem in FAST v7 modeling a turbine without blades by setting the blade masses of each blade to zero and disabling all blade degrees-of-freedom (DOFs). But in FAST v7, you will need to modify the source code to model a one-bladed turbine or a two-bladed turbine 120-degrees apart. Basically, if you define a three-bladed rotor, set the blade mass of one or more blades to zero, but enable a blade DOF, FAST will be unable to solve the equations of motion because the mass matrix for the enabled blade DOFs will be zero. You could get around this by modifying the source code so that you only enable the blade DOFs for the blades whose mass is nonzero.

Best regards,

Ok, thank you very much for the quick response.