On Thu, 18 Apr 2013 12:18:26 -0500, Tim Wescott
wrote:

On Thu, 18 Apr 2013 12:35:44 -0400, Ed Huntress wrote:

On Thu, 18 Apr 2013 11:08:52 -0500, Jon Elson
wrote:

Ed Huntress wrote:


FWIW, it looks to me like this engine violates a basic point of IC
engine design for thermal efficiency. By using a separate combustion
chamber, it multiplies the surface area relative to the volume of
combusted gas. The result is a very high ratio of lost heat to useful
heat.
Yes, I was thinking the same thing as soon as somebody brought up "how
do you cool it?" So, is the combustion chamber in the non-rotating
center?

It appears to be.

it seems like it has an intake/compression
piston and a power/exhaust piston.

Yeah, it's a split-cycle engine. But it doesn't appear to transfer the
unburned mixture to the power-piston chambers. Apparently it burns the
mixture first, in a separate chamber, and then opens a port from there
to a power-piston cylinder.

It's like a turbine engine with pistons doing the compressing and
delivering the power, rather than turbines. Or so it appears.

If there's also a separate
combustion chamber, than that's THREE places for heat loss!

Jon

Yes, with the separate combustion chamber being by far the biggest one,
because it not only is losing compression heat; it's also losing heat of
combustion.

There have been numerous split-cycle engines, including a number of
two-cylinder split-cycle motorcycles, and some were very successful.
They can combine pre-compression with as much supercharging as you want.
But they compressed the mixture in one cylinder and transferred it to
the other, where it was burned. There must have been some thermal loss
inherent in the design but at least the *hot* gas was confined to the
power cylinder.

This one looks different. At first, when I read "split-cycle," I thought
is was really a conventional split-cycle with what amounts to an
external swash plate (there have been many swashplate and wobble-plate
engines, but they don't use an external cylinder to handle the eccentric
drive motion).

But the central combustion chamber make this one an entirely different
thing. I wonder why they do it that way? It may be necessary because of
the geometric relationships of the cylinders.

I wonder which is the Grand Inspiration that led to everything else --
the cylinder arrangement, or the combustion chamber arrangement?

Just guessing here, but I'd guess it was the balance and compactness
enabled by the radial configuration with the external cylinder for
transmitting power.

A rotary swashplate engine is more compact, but there is a rotating
rocking couple in the balance. I can't do the balance in my head on
this radial engine, but, at first glance, it does look inherently
balanced.

--
Ed Huntress