Reply To: Porta's Derivation of Lempor Theory
Martin, I’m probably not the best person to discuss this with, because I am agreeing with everything you say!. I guess the angle comes from interpretation (or otherwise!) of Porta’s Lempor paper.
My background is as an electrical engineer, but I’m happy to pick up any snippets of wisdom that I can on this subject. I have my doubts about the turbulent entrainment theory, which seems to suggest the more turbulence you produce the better the entrainment will be.
Regarding the geometry I’ve been toying with idea of the nozzles angled to produce a hyperboloid steam jet, possibly feeding into a hyperboloid chimney.
How would you make one? It’s possible to produce a casting from a polystyrene pattern, and you can cut polystyrene using a hot wire, set to the appropriate angle to give a hyperboloid.
If you then wanted to improve the surface finish you could electrochemically machine the surface using an electrode made from wires arranged in a hyperboloid.
I once found a patent from the 1950’s describing a hyperboloid ejector, but the internet link has now disappeared. If anyone is interested in making one I’d be happy to help with the mathematics.
In your experience have you come across anything like this?