How can a wind velocity file be read by the FAST software

Wind & Water Inflow Turbulence
1

Dear all,

I am using FAST v8.16 and trying to adopt a InflowFile which contains the wind velocities generated by myself. Then I set the the parameter WindType to be 6 in the input file for In InflowWind v3.01. However, this means the wind velocities will not be read from the file, but be calculated by a user defined function. So, I wonder if there is any method to import a wind velocity file to the FAST software.

Thank you in advance for your kind help

Best regards,

Yuqi CAO

2

Dear Yuqi,

If you have time series of wind at one point and it is reasonable to assume uniform wind across the rotor (perhaps with shear), then you can use WindType = 2 (uniform wind files) to define your wind. See the InflowWind User’s Guide for more information: wind.nrel.gov/nwtc/docs/InflowWind_Manual.pdf. If your wind data is more complicated, please clarify.

Best regards,

3

Dear Jason,
Thank you very much for your kindness. Actually I meant that I wanted to import time series of wind velocities at many points to FAST. For example, the wind velocities of different points in the rotor plane are generated by MATLAB firstly and the response of the turbine is going to be studied using FAST. The wind velocities may be under the condition of typhoon or other load cases. AS a result, the wind velocities need be transfered to FAST. SO, how can these data be imported to FAST? Thank you again for your kindness.
Best regards,
Yuqi CAO

4

Dear Yuqi,

One way would be to update your MATLAB script so that it can write the wind data in a format that the InflowWind module of FAST can already read e.g. binary TurbSim format. Again, see the InflowWind User’s Guide for a detailed description of the formats: wind.nrel.gov/nwtc/docs/InflowWind_Manual.pdf.

Best regards,

5

Dear Jason,
Thank you very much. I will have a try.
Best regards,
Yuqi Cao

6

Hello everyone,
I have a question about preparing the wind file to be read by FAST from wind data that I have already. The data are a bit different compared to the available options that I can use from InflowWind (such as tornado wind field).

So my obstacle currently is that I don’t know how to prepare the wind file for FAST from the data that I have already. Anyone can give me an advice regarding that?
Thanks in advance.

7

Dear Mohamed,

A tornado-like structure is likely three-dimensional in nature, so, none of the existing wind-file formats used by the InflowWind module of FAST are likely suitable. Instead, I would suggest using WindType = 6 and define your wind through the UserWind subroutine, which requires that you implement your own wind in source file IfW_UserWind.f90, and recompile FAST.

Vest regards,

8

Dear Dr.Jonkman,

Thank you for your advice. I am trying to edit the user defined f90 file but it is dependent on the libraries etc. I have the 3D data, could you please advice me where can i input the velocity arrays? Thanks again!

9

Dear Mohamed,

I would hope that modifying the IfW_UserWind.f90 source file is straight forward. Without changing the subroutine arguments, SUBROUTINE IfW_UserWind_CalcOutput() receives the (X,Y,Z) positions of a number of analysis points as input and expects the ambient wind velocity (U,V,W) to be output at these points (FAST will decide where it needs the wind to be defined i.e. which points to send to the SUBROUTINE). You can use SUBROUTINE IfW_UserWind_Init() to initialize any data (e.g. reading in data from a file) and setting constants and can use SUBROUTINE IfW_UserWind_End() to deallocate any data and close files (if necessary).

Best regards,