Cd Drag Coefficient in TOWER

Wind & Water Structural Analysis
1

Hello Dear Jonkman
I would like to inform myself about some simulations in special cases

I’m currently working on changing the tower’s CD (Drag coefficient). Focusing on special geometries (Non-circular towers). Do you know any material/papers about solving this problem via FAST?

I’ve been changing the Cd as a function of the Reynolds number (Aerodyn 14).
However in some cases I need to get the wind speed in the tower, and I only had success on the Aerodyn 15. Is it possible to change the Cd to aerodyn15 or get the wind speed profile in the tower from aerodyn 14?

Thank you a lot!

2

Dear Carlos,

I would generally recommend using AeroDyn v15 over AeroDyn v14 as we intend to deprecate AeroDyn v14 soon. The tower aerodynamic load model of AeroDyn v15 is far more robust than the one in AeroDyn v14, but as you’ve noted, a Reynolds’ number-dependent drag coefficient could be specified in v14, but not in v15. To get around this in AeroDyn v15, other than modifying the source code, you could update the AeroDyn v15 input file depending on the ambient wind speed of the simulation.

I have not studied noncylindrical towers, but these would require modeling changes to how AeroDyn considers the tower aerodynamic loads and the influence of the tower on the aerodynamics of the rotor.

Best regards,