Re: boat propulsion - miniature computer-controlled steam plant?

"Peter Fairbrother"  wrote in message news:usaous$kv5m$1@dont-email.me...
On 06/03/2024 14:07, Richard Smith wrote:

Started on path of learning "embedded electronic devices".
Typically boards about 50mm square with inputs, outputs and a
microprocessor - as would be used to control eg. a washing-machine.
>
The thought must occur to an "on the spectrum" mind - for a boat -
eg. auxiliary power for a sailing yacht...

No, first a steam engine is not a Carnot cycle engine, it is a
(hopefully condensing) Rankine cycle. Second, small - and by small I
mean anything smaller than huge - turbines are inherently less efficient
than reciprocating engines. You'll be lucky to get 15% even with really
good design.
You might want to look at Sterling engines.
Peter Fairbrother
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For aircraft the break-even point between recips and jets is considered to be around 300HP, though there are smaller jet engines down to model size.
https://www.smithsonianmag.com/air-space-magazine/the-little-engine-that-couldnt-6865253/
At 375 MPH one HP equals one pound of thrust.
Unless you build at the low end of buy new and bolt together industrial size there will be lots of custom machining involved. Using surplus equipment may also require machining to make the parts connect together. I found that cheap and useful things were often available because they had unusual mounting or shaft coupling etc.
On the sawmill I paid as much for a new extension shaft, jaw couplers, supporting bearings and a pulley as for the new 6.5 HP gas (petrol) engine. The point was to have all the exposed moving parts on the tooth side and the engine and its controls on the guarded back side in easy reach.