Keith, there is "one of Nigel's up" (may be he should panit his bright red). Dick's venturi isn't really a venturi, it's an ejector ... I can tell how well you've read all my hours of hard work! I was going to suggest a separate page on ejectors as I believe they are less susceptible to back pressure/ filled pipe issues and could possibly perform better. Now you mention your leap forward in hydrodynamics theory, I recon you're just the chap to write it!
I'll try and sort the venturi page layout, out, in the next couple of days.
