Error reading a bladed .wnd and .sum file using FAST v8.15

Wind & Water Computer-Aided Engineering Software Tools
1

Hi,

After searching the forum for answers and not finding any (or overlooking them) I decided to ask the question directly to see if someone has had this problem as well and can point me in the right direction.

I am trying to use a Bladed v4.4 .wnd binary file in FAST v8.15 but I keep getting an error stating the following:

FAST_InitializeAll:InflowWind_Init:IfW_BladedFFWind_Init:Read_Summary_FF: Error reading hub
height from FF summary file.

I get the error after applying the specific format to the .sum file described in the InflowWind manual (Apendix F). While searching the forum I found a script that Bonnie made for reading Bladed .wnd and .sum files which I used to see if I could find the problem but it gives me the following error:

Error using zeros
Maximum variable size allowed by the program is exceeded.

Error in readBLgrid (line 199)
velocity = zeros(nt,nffc,ny,nz);

Basically, the velocity matrix is too big for Matlab. I am wondering if the problem is due to the format of the binary .wnd file but I am just guessing at this point.

Has anyone had this problem before? Is my .sum file not the right format (attached)?

Any help will be greatly appreciated.

Thanks,
Jan
Wind_10_1.txt (894 Bytes)

2

Dear Jan,

I’m assuming you are making your summary (*.sum) file associated with Bladed-style full-field wind (FF) files manually? It doesn’t look like you’ve made it correct. E.g. in the first line for CLOCKWISE, you must specify “T” or “F” for “True” or “False” instead of writing “T/F”. In the second line, you must provide a numerical value instead of “NUM” for the HUB HEIGHT. There may be other errors, but I stopped reviewing the file there. It may help to start with a TurbSim-generated .sum file and modify that rather than making one manually.

Are you generating your binary Bladed-style FF file from Bladed? If so, take note of the comment from the InflowWind User’s Guide:

I hope that helps.

Best regards,

3

Dear Jason,

Thank you for your comments. To answer your question, I am trying to use a Bladed generated FF binary file in FAST by modifying them to be read by InflowWind. I am aware that InflowWind does not add a mean wind profile and thus I am only doing this analysis to compare results between both codes as a test.

I thought that I would only need to add the format specified in the InflowWind users guide to the Bladed file, but I think I misunderstood. Does it need to have the same format as a Turbsim generated .sum file in order to read the Bladed generated binary wind file in InflowWind?

Many thanks,
Jan

4

Dear Jan,

OK, thanks for clarifying

You don’t need to use TurbSim to generate a sample “.sum” file, but I thought that may be easier because it seems that there was some confusion regarding “T/F”, “NUM”, etc. Appendix F from the InflowWind User’s Guide is correct as far as I know.

Best regards,

5

Jason,

Thank you for the clarifications. The model is working now.

Best regards,
Jan

6

Hi Jason,

I have a question regarding the statement in the InflowWind user manual and the one you mentioned previously which says:

“Wind files generated by Bladed can be read, but it should be noted that InflowWind does not add a mean wind profile.”

Could you clarify what would be the effects of not adding the mean wind profile on the results? Would this affect the controller behaviour?

Thanks,
Jan

7

Dear Jan,

That means that Bladed-generated .wnd files don’t include the mean wind speed and vertical shear; that is, the Bladed-generated .wnd files only store the fluctuations of wind about the mean. (Within Bladed, the mean wind speed and vertical shear are added to the fluctuations before being used in the aerodynamic calculations.) InflowWind will not add the mean wind speed and vertical shear to the fluctuations, so, Bladed-generated .wnd files should not be used within FAST without first augmenting the Bladed-generated .wnd files to add the mean wind speed and vertical shear. This augmentation could be done manually in a pre-processing step.

Best regards,

8

Dear Jason,

Thank you for your prompt answer to my question. It is now very clear.

When you say that it can be done in a pre-processing step, are you referring to doing the augmentation in the .sum file that FAST will read or directly on Bladed software?

Regards,
Jan

9

Dear Jan,

I mean that the Bladed-generated .wnd would have to be modified directly before use within FAST/InflowWind. Developing a .sum file is also required.

Best regards,