I think the useful information here is effects of various cross sectional shapes
on flow through a venturi. Calculating specifics yields a flow value which is useful to
someone, but not me.
As I recall, Frank Williams had a couple of good articles about venturis in Stunt News,
years ago. (That guy is a genius, of course.)
I'm guessing that turbulating flowed air could be useful in atomizing the fuel. One thing
we do with our stunt motors is to constrict air flow and operate it in an area nowhere
near maximum efficiency or power.
Or not.
For me, it's pretty much a hog looking at a wrist watch. Sorry.
L.
"Like dogs in a wheel, birds in a cage, or squirrels in a chain, ambitious men still
climb and climb, with great labor, and incessant anxiety, but never reach the top." -Robert Burton (1576-1640)