Some questions about WT_Perf

Hello everyone:
These days I’m studying WT_Perf. But some problems came up.

  1. When WT_Perf Archive is extracted, why can’t I execute WT_Perf.exe directly, the dos window just show up nearly one second and disappear, should I put some other files in the same folder of file WT_Perf.exe?
  2. As the WT_Perf Manual doesn’t say how to use those FORTRAN files, how can I compile the source files of the extracted archive? Which Fortran files should be put in the same folder? And is there a sequence to compile those FORTRAN files?
    Best regards.


You cannot run WT_Perf by clicking on the EXE file. It must run from the command prompt and you much tell it which input file to use.

Please read my short paper on using our codes. You can get it here:

After that, please read the WT_Perf User’s Guide. On the first page is a very short section that shows the syntax of the WT_Perf command.

If you want to recompile it, include all the files in WT_Perf’s source folder and the appropriate files from the NWTC Subroutine Library. Please read this web page to see which files you should include in your project:

Download the latest archive of the library and expand it. The files you will need from it are in the Source folder.

Hi Marshall:
Thanks for your fast reply. I’ll try again after your instructions.
Best regards and I really appreciate your work.

After that, please read the WT_Perf User’s Guide. On the first page is a very short section that shows the syntax of the WT_Perf command.

I did it follows the “Installing NWTC Design Codes on PCs Running Windows XP” instuctions, but when I entered Wt_Perf <Test01_UAE.wtp>, there shows Command syntax is incorrect. While I entered Wt_Perf in the command window, it shows:
[b] Running WT_Perf (v3.10, 16-Dec-2004).
Linked with the NWTC Subroutine Library v1.00b-mlb (15-Oct-2004).
Syntax is: wt_perf

Aborting WT_Perf.[/b]
I did this under the folder in E:\AirfoilPrep_v2p2 folder, while my Test01_UAE.wtp file is in E:\AirfoilPrep_v2p2, my WT_Perf.exe file is under the folder of E:\AirfoilPrep_v2p2\WT_Perf, my Batch file is under the folder E:\AirfoilPrep_v2p2, the last one’s content is E:\AirfoilPrep_v2p2\WT_Perf\WT_Perf.exe %*.

Can you tell me what’s wrong with that?
Best regards.
Zhang. Streamkite

If my input file is called “MyFile.wtp”, the syntax is:

wt_perf MyFile.wtp

The angle brackets “<>” are just showing you where you need to enter the file name. Don’t use them in the command.

Hello Everyone!
I am also using WT_Perf these days. I have one question about it. In the section of Turbine Date of Input file, I set the following data for turbine
Rotor Radius: 9.39 m
Hub Radius: 0.819 m
Num Seg: 4
RElm Twist Chord AFfile PrntElem
1.320 10.000 1.50000 1 True
3.320 08.000 1.12500 1 True
6.320 06.000 0.87500 1 True
9.320 04.000 0.50000 1 True
but when I ran the program, it says
“The sum of the lengths of the segments does not match the rotor radius. The segments add upto a rotor radius of 10.819 m instead of the specified 9.39 m. They must agree within 0.5%”.
Query 1: How the length of rotor radius is calculated?
Querry2: How the length of segments are calculated?.
Query 3: In the Airfoil folder under the folder CART3, lift and drags coefficients are given for various airfoils. The same folder contains some airfoils which contain names like C3_06_6S818+1S816 or C3_07_5S818+2S816 and so on. Does this show mix of air foils and if yes, what the number before airfoil shows i.e. 6S818 or 1S816. If one have the coordinates of S816 and S818, how these will be interpolated?

Best Regards

Please read the following post:

Good afternoon Marshall,

I am facing the same problem as Abdull, and unfortunately the link to the thread you’ve posted

doesn’t work anymore.
Could you re-establish this thread if it’s possible, please, or help me to solve my problem?

Here are my “Turbine Datas”

3                   NumBlade:                  Number of blades.
 1.211               RotorRad:                  Rotor radius [length].
 0.05               HubRad:                    Hub radius [length or div by radius].
 0.0                 PreCone:                   Precone angle, positive downwind [deg].
 0.0                 Tilt:                      Shaft tilt [deg].
 0.0                 Yaw:                       Yaw error [deg].
15.0                 HubHt:                     Hub height [length or div by radius].
 8                   NumSeg:                    Number of blade segments (entire rotor radius).
   RElm     Twist        Chord  AFfile  PrntElem
0.303  	6.661	0.2286	1	True
0.557        6.626	0.2286	1	True
0.62	        5.264	0.2286	1	True
0.683	4.399	0.2286	2	True
0.787	3.891	0.21961	2	True
0.908	3.394	0.19894	2	True
1.029	2.767	0.16258	2	True
1.133	1.7    	0.09743	2	True

and it appears to me the following message:

My question is: how can I choose the radius element (RElm), respecting my geometry?

Thank you for your work and your attention

Hello there

I am using WT_Pref and I am getting the same error message regarding the blade segment which is not a physically realizable blade, and the link that is posted several time as shown below is found to be non existing.
did someone figured out how to solve this?

Thanks in advance

Greetings from Germany



I’ve been assigned to a high-priority project this fall and have not had time to keep up with the forums. I have created a FAQ and one of the questions is about locating analysis nodes. You can find the answer here: