On Tue, 15 Nov 2016 11:51:42 -0000
"NY" wrote:

"Davey" wrote in message
news

snip

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.

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?

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.

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.


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.


The aircraft Rotary engine was invented before the Wankel, so to me it
has the prior claim.
As to the questions about supercharging etc, I have no idea. I just
like the contrariness of having a huge mass rotating. I also
appreciated watching Tractor Pulling in the US, where a machine with
three Allison aircraft engines would be hauled to a stop by
nothing more than earth.
Try Youtube for 'Starting Giant Engines'.

--
Davey.