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Perl script for Riblett airfoil generation

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addaon

Well-Known Member
Supporting Member
Joined
Feb 24, 2008
Messages
3,976
Location
Kanab, UT
I've been working on a project that required generating Riblett airfoils again, and yet again I ended up writing a simple perl script to help. I've attached that script in case its useful to others; I'll probably update it occasionally, mostly to add more features for my own use. Be aware: All values are typed in by me, with little double checking, so be careful and let me know about any errors!


In its simplest form, you can run the script as, for example, ./riblett.pl 35A315. If you do, you'll see output like this:


Code:
Series:    35
Cusp:      no (A)
Camber:    3 (design CL 0.3)
Thickness: 15%
Options:   none




         35A315
  Sta      upper      lower
  0.00      0.000      0.000
  0.25      0.938     -0.812
  0.50      1.323     -1.083
  0.75      1.618     -1.278
  1.25      2.119     -1.569
  2.50      3.079     -2.079
  5.00      4.470     -2.766
  7.50      5.500     -3.264
 10.00      6.332     -3.662
 15.00      7.625     -4.259
 20.00      8.577     -4.661
 25.00      9.264     -4.918
 30.00      9.724     -5.044
 35.00      9.953     -5.039
 40.00      9.959     -4.911
 45.00      9.758     -4.672
 50.00      9.357     -4.359
 55.00      8.755     -4.019
 60.00      7.998     -3.642
 65.00      7.120     -3.226
 70.00      6.152     -2.784
 75.00      5.135     -2.327
 80.00      4.114     -1.868
 85.00      3.095     -1.409
 90.00      2.074     -0.950
 95.00      1.053     -0.491
100.00      0.032     -0.032


I also support a bit more flexibility in cambers and widths. Cambers between 0 and GA-6 are interpolated; for non-integral cambers, use brackets. Arbitrary thicknesses are supported; for non-integral thicknesses, use brackets. So ./riblett.pl 35A[2.5][14.5] is valid.


I support a single option at this point -- if sharp is specified on the command line, the coordinates are tweaked to make the trailing edge perfectly sharp. Some but not all Riblett thickness distributions have this property, and it's pretty important for comparing different airfoils in, for example, XFoil.


Speaking of XFoil, if output files are specified on the command line, data of the appropriate format is written to that file. I currently support .txt (human-readable table), .dat (XFoil-style), and .dxf (for Rhino import, etc). Pulling it all together, then, you might try something like this: ./riblett.pl 37A3[14.5] sharp /tmp/out.dat /tmp/out.dxf.


Code:
Series:    37
Cusp:      no (A)
Camber:    3 (design CL 0.3)
Thickness: 14.5%
Options:   sharp


Writing to /tmp/out.dat...
Writing to /tmp/out.dxf...


Let me know if this is useful to you guys, and if there's any other features that you'd like to see added. As mentioned, I'll probably be fiddling with it for a bit, so good time to ask!


View attachment 37410
 

Attachments

  • riblett.pl.zip
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