I'm a recent arrival at Maple Primes (as in earlier today), and I seem to recall a much older version of either Maple, Matlab, or Mathematica having a 3D plot example of a "Schauberger" tube. I've looked through my old files and can find nothing.
These are similar to a tornado or water whirlpool profile, so I'm supposing that cylindrical coordinates are a suggested goemetry. A "decaying radius" spiral looped inside the "Gabriel's Horn" elsewhere on Maple Primes has a similar 3D profile, but the pipes that Herr Schauberger patented in Austria long ago also decreased in pipe diameter as the spiral radius decreased inward.
I'd like to to some fluid modeling on this old tubing design, but I haven't found the proper 3D profile for the tube itself.
Any help is appreciated in advance,