On Mar 15, 3:47*pm, Bruce L. Bergman
wrote:
On 15 Mar 2009 17:04:43 GMT, steamer wrote:

wrote:
I build 1/16 scale models of locomotive steam turbo-generators, fully
functional.
* *--You have *got* to post some photos! :-)

Agreed! *That's been one of the big bugaboos to building a small steam
launch - I wouldn't have any way to run the nav lights and the oil
burner for the boiler. *And while a double expansion auxiliary motor
spinning a Car Alternator through a step-up gear would work...

* But it sounds like your turbine is aiming for 10W output, and the
small boat would need more like 1KW to 2KW output - unless you've got
a lot of excess capacity available, it might have to scale up one
notch.

* -- Bruce --



I shall make an effort to post some pics over the next little while.

For electric power on a steam yacht I'd convert a 2 cylinder cast iron
automotive air conditioning compressor into a steam engine -I did this
for a friend- and run a good quality automotive alternator via a
toothed belt, speeding up the drive by say 3:1. This would keep
things quiet. Plans for this conversion were available in the popular
do-it-yourself press in the late '70's or so.

As to powering a model racing boat... It has been done. There is -
another- little book available, but not on-line as far as I know,
entitled Experimental Flash Steam. It covers the topic of steam
powered racing boats using flash or monotube boilers with piston steam
engines mostly; one experimenter did build a turbine powered boat.

It is a fascinating book if you can find a copy, covering details such
as feed, fuel, and oil pumps, and controls.

I think that a 1 to 2 KW small steam turbine is doable especially if
you don't need electric output or if it doesn't have to look "scale".
My little turbine's output is primarily limited by the scale
alternator... you can only squeeze so many turns of a certain sized
wire into the available space; whereas the power can always be
increased by increasing the number of steam nozzles until you have
reached full admission ie. a full 360 deg. nozzle ring. Nothing to
stop one from fitting, at the design stage, 30, 40, or 60 steam
nozzles.

The way I would approach it would be to design the steam nozzles as a
full-admission nozzle ring and 3 or 4 pass terry turbine wheels as
these are quite easy to make. With a small CNC mill even Laval (or
was it Parson?) turbine wheels are not difficult to make.

Turbines are a fascinating subset of the live steam hobby and I would
encourage those interested to have a go. But read up on it first as
there is no sense in re-inventing the wheel.

Wolfgang