Asking about error reading data from .wnd

Dear Jonkman,

I have a problem when i run FAST code.
The program shows this error:

When I run FAST code with Noshear.wnd, the program can run.
But when I replace that file by another file (from Turbsim program with turbulence), it occurs this problem.
Please explain for me about this error.

Thank you very much for your help.
Sang.Le

Dear Sang.Le,

In FAST v7, the InflowWind module of FAST had to determine what type of the wind file the user specified, because the user did specify the file type directly. When TurbSim generates a wind data file in Bladed binary format (.wnd), it also generates an associated summary (.sum) file that would help InflowWind properly interpret the binary format. If InflowWind can’t find the *.sum file associated with the *.wnd file, InflowWind will assume the *.wnd file is a so called “hub-height” file rather than a Bladed binary file. So, when using turbulent wind data files in Bladed format, make sure that both *.wnd and *.sum are available in the same directory called by InflowWind.

I hope that helps.

Best regards,

Dear Jonkman,

Thank you very much for your help. Your advice is very useful for me.
My simulation can run well.
However, I want to ask you about other problem:
When I set FlapDOF1,2 and EdgeDOF are True, my program has a problem as follow:

When I set FlapDOF1,2 and EdgeDOF are False, the program can run.

I think that the reason is large blade deflection.
So, what can I do to solve this problem?
Please explain and teach for me.

Thank you very much for you help.

Best regards.
Sang.Le

Dear Sang.Le,

The command prompt indicates that your wind file is only 2-m wide and 2-m high (from 0.6 to 2.6 m above ground), and the blade node is 116 m above the ground. I’m not sure what turbine you are trying to model, but these don’t sound consistent.

Similar questions have been asked on the forum; please use “Search…” in the upper-right corner to see how similar problems have been solved in the past.

Best regards,

Dear Jonkman,

Thank you very much for your reply.

I’m sorry because of information deficiency.
I want to compare simulation results and experimental data.
I’m simulating for a model wind turbine which is used to experiment in the wind tunnel.
D = 1.6m, hub height = 1.6m, avistar blade…

I changed some parameters when I run program. But it still has error.
I don’t know why is the Z direction of 116m? Where is my mistake?
Please explain for me.

Best regards.
Sang.Le

Dear Sang.Le,

My guess is that you took one of the sample FAST models, made the turbine geometry smaller, and didn’t touch the mass or stiffness distributions in the blades or tower or modify the time-step accordingly. For the same mass/stiffness, but smaller geometry, the natural frequencies would increase dramatically, requiring a much smaller time step for numerical stability. You’ll need to set up the model consistently (in terms of mass, stiffness, geometry, and time step) if you wish to run simulations with degrees-of-freedom enabled.

Best regards,

Dear Jonkman,

Thank you very much for your comments.

I will check again and try to run program.
If It has problem, I will ask you later.

Best regards.
Sang.