Problems in the simulation of IEA 15MW Activefloat floating wind turbines

[tclblby]

The simulation worked well in the step wind field, here is some of the results.

However, when I change the wind into a NTM wind field(10.5m/s)，the controller seems to be unwork.
Generator speed: 7.3 RPM, Pitch angle: 0.0 deg, Power: 13668.2 kW, Est. wind Speed: 10.5 m/s
Generator speed: 7.4 RPM, Pitch angle: 0.0 deg, Power: 14208.8 kW, Est. wind Speed: 10.5 m/s
Generator speed: 7.4 RPM, Pitch angle: 0.0 deg, Power: 14108.4 kW, Est. wind Speed: 10.8 m/s
Generator speed: 7.4 RPM, Pitch angle: 0.0 deg, Power: 14011.6 kW, Est. wind Speed: 11.1 m/s
Generator speed: 7.4 RPM, Pitch angle: 0.0 deg, Power: 13962.6 kW, Est. wind Speed: 11.2 m/s
Generator speed: 7.4 RPM, Pitch angle: 0.0 deg, Power: 14096.8 kW, Est. wind Speed: 12.2 m/s
Generator speed: 7.5 RPM, Pitch angle: 0.0 deg, Power: 14272.4 kW, Est. wind Speed: 12.8 m/s
Generator speed: 7.3 RPM, Pitch angle: 0.0 deg, Power: 13575.2 kW, Est. wind Speed: 12.6 m/s
Generator speed: 7.3 RPM, Pitch angle: 0.0 deg, Power: 13406.7 kW, Est. wind Speed: 12.2 m/s
Generator speed: 7.3 RPM, Pitch angle: 0.0 deg, Power: 13518.0 kW, Est. wind Speed: 12.0 m/s
Generator speed: 7.4 RPM, Pitch angle: 0.0 deg, Power: 13956.8 kW, Est. wind Speed: 12.6 m/s
Generator speed: 7.4 RPM, Pitch angle: 0.0 deg, Power: 13906.3 kW, Est. wind Speed: 13.1 m/s
Generator speed: 7.3 RPM, Pitch angle: 0.0 deg, Power: 13591.8 kW, Est. wind Speed: 13.2 m/s
Generator speed: 7.4 RPM, Pitch angle: 0.0 deg, Power: 13729.2 kW, Est. wind Speed: 12.9 m/s
Generator speed: 7.3 RPM, Pitch angle: 0.0 deg, Power: 13424.4 kW, Est. wind Speed: 12.7 m/s
Generator speed: 7.3 RPM, Pitch angle: 0.0 deg, Power: 13276.4 kW, Est. wind Speed: 12.6 m/s
Generator speed: 7.3 RPM, Pitch angle: 0.0 deg, Power: 13878.7 kW, Est. wind Speed: 12.7 m/s
Generator speed: 7.4 RPM, Pitch angle: 0.0 deg, Power: 13829.2 kW, Est. wind Speed: 12.4 m/s
Generator speed: 7.4 RPM, Pitch angle: 0.0 deg, Power: 13949.4 kW, Est. wind Speed: 12.7 m/s
Generator speed: 7.4 RPM, Pitch angle: 0.0 deg, Power: 13615.0 kW, Est. wind Speed: 12.5 m/s
Generator speed: 7.3 RPM, Pitch angle: 0.0 deg, Power: 13375.7 kW, Est. wind Speed: 11.7 m/s
Generator speed: 7.3 RPM, Pitch angle: 0.0 deg, Power: 13442.9 kW, Est. wind Speed: 11.2 m/s
Generator speed: 7.3 RPM, Pitch angle: 0.0 deg, Power: 13476.6 kW, Est. wind Speed: 11.2 m/s
Generator speed: 7.3 RPM, Pitch angle: 0.0 deg, Power: 13148.4 kW, Est. wind Speed: 11.2 m/s
Generator speed: 7.2 RPM, Pitch angle: 0.0 deg, Power: 13033.8 kW, Est. wind Speed: 10.9 m/s

The pitch angle of the blade and the power all can't perform as expected even if the wind speed has exceeded the design wind speed(10.5m/s) for a long time.

How could it happen? I only change the wind field in this two simulations.

[tclblby]

I try to increase the wind mean speed to 15m/s, the results shows that the controler seems to be insensitive.

[ptrbortolotti]

hello @tclblby , we don't really understand what the problem is. can you please try to explain your concerns again?

[dzalkind]

It might help if you started with a 600 second simulation and the default output format. It's possible that the turbulence wind input you are using is stretched in time too much. How are you generating the wind input?

https://github.com/IEAWindTask37/IEA-15-240-RWT/tree/master/OpenFAST/IEA-15-240-RWT-UMaineSemi

[tclblby]

@ptrbortolotti ,thanks for your attention.
I'm trying to repeat the simulations using the modal Acivefloat in this article:"Response of the International Energy Agency (IEA) Wind 15 MW WindCrete and Activefloat floating wind turbines to wind and second-order waves(https://doi.org/10.5194/wes-6-867-2021)".
I succeed in the first eleven load cases (in the table 8. of the article, including static equilibrium, free decay, step wind, regular waves and irregular waves). I get the same results with this article. However, i got fail in the load case with ESS waves and NTM wind field as the figures above.
It seems that the controler shows different characteristics under the step wind and the NTM wind. In the NTM wind field, the controler can't make the BLpitch change within a reasonable range. Even if the wind speed fluctuates dramatically between 10-20m/s, the BLpitch's fluctuation range is only 0.6 °.
I can't understand how could it happen. I never change the controler file in these simulations. So i have to come here and ask for some help.

[tclblby]

It might help if you started with a 600 second simulation and the default output format. It's possible that the turbulence wind input you are using is stretched in time too much. How are you generating the wind input?

https://github.com/IEAWindTask37/IEA-15-240-RWT/tree/master/OpenFAST/IEA-15-240-RWT-UMaineSemi

@dzalkind ,thank you.
I used TurbSim to generate my wind field. This is the .inp file i used.


This is some messages in the .fst file.

You means that the "AnalysisTime" in the .inp file is too long? I setted it as long as the whole simulation.