Hello everyone,
I am trying to model the 15 MW IEA Monopile and I would like to ask some questions about the workflow one has to follow to correctly describe the mode shapes of the tower and blade considering they are essential for the ElastoDyn input file. My goal is to be able to change the length of the pile and the wind speed at hub height.
I have read other posts on this forum and I have concluded the following:
For the tower
The flexible tower (uncoupled) mode shapes can be computed using BModes_JJ considering the mass and stiffness matrices from the SubDyn summary file to account for the new boundary conditions at the TP (i.e. new pile length). Subdyn also includes an SSI file which considers the interaction between pile and soil so the spring stiffness at seabed will be different and will be accounted for(Coupled springs method). From all of the above and with the help of the poly fitting spreadsheet the new 6 degree polynomial coefficients can be computed.
For the blade
Every time I want to change the wind speed at hub height I would have to change the pitch and rotor speed setting (initial conditions of the simulation) in the ElastoDyn input file. This also has to be defined into the BModes_JJ .bmi file for the blades and calculate the new (uncoupled) mode shapes for the elastic blade. In the end following a similar procedure to the tower mode shapes the coefficients can be used as inputs for the ElastoDyn.blade file.
Is this procedure correct?
Thank you so much for your time!