On 15/11/16 11:51, NY wrote:

Rotaries have always baffled me: how do you get your supply of fuel to
the cylinders without leakage where the stationary fuel tank feed meets
the rotating cylinder block. It's not like an electric motor where slip
rings or a commutator serve the equivalent purpose with electric
current: in the case of fuel, you need to prevent leakage.

https://en.wikipedia.org/wiki/Rotary_engine


What was the advantage of rotating the cylinder block? Was is mainly
that the movement of the block though the air provides additional air
currents over the fins and allows the cylinders to be air-cooled rather
than water-cooled? Or was there any other advantage?


No flywheel = lighter.

Presumably rotaries tend to be noisier because each cylinder has its own
separate exhaust pipe - or if there is a common exhaust pipe it cannot
have such elaborate silencer because of the need to balance and minimise
the rotating mass.

No aircraft engine ever used a silencer as far as I know. Some night
fighters used some kind of flame baffles so they didnt show up at night.



Can rotaries be made to made with supercharging (ie a compressor to
increase air intake pressure)? I suppose it's possible if the compressor
is made to spin with the cylinder block. Turbocharging (using exhaust
pressure rather than crankshaft rotation to drive the inlet compressor)
could be "interesting" :-) In either case, you've got the problem of not
being able to have a large (and therefore heavy) air reservoir to store
boost pressure for cases where the throttle is opened on a slow engine
and high boost is needed at a time when the engine can't yet generate it.

I am sure it could be done, but tehre is no onterst in WWI style
rotaryty engines at all, except tp power reproduction planes, and those
are pretty faithful to the original designs


Is "rotary" the correct word for this type of engine, given that the
word is also used to describe a Wankel engine which works in a very
different way.

Rotary is applied to any engine where large parts of it go round.

The Le Rhone and Le Clerget's were there well beforer Wankel.

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