On Wed, 11 Mar 2009 01:22:23 -0400, "Ed Huntress"
wrote:

Has anyone ever built a model of a de Laval turbine? I mean one with a real
de Laval nozzle, that put out some power.

Or do you know of a good text about them? Most are either too simple or
they're too abstract on the engineering theory side.

I'd like to build a model of one, but not just a steam windmill. g I'd
like to have some real de Laval nozzles on it.

Thanks to any steamers who know about these motors.

Ed, I'm not a steamer but have made quite a few de Laval nozzles in
graphite, for small rocket motors. For motors under 1.5" diameter,
the nozzles were (usually) formed using an ordinary 82 degree
countersink for the entrance cone and a 29 degree cone-shaped carbide
burr for the exit cone. They worked a treat.

Rules of thumb for rocket motors operating at about 600-1000 psi (may
have nothing whatever to do with steam): diameter of exit is about 2x
diameter of nozzle throat; throat length is as short as is practical
but should not exceed 1/2 the throat diameter; rounding off the sharp
edges of the throat will improve performance.

Hope this helps -- Terry
"As a matter of fact, I *am* a rocket scientist... :-)