There was one mounted on the back of a Long-EZ in the Scaled hangar

at

Rutan's birthday. Four real long tubes out the back.

 I also saw the pulse detonation engine on the Vari EZ at Oshkosh. This is

undoubtedly
a "small business grant" from NASA. They claimed about 100 pounds of

thrust

from
a system that weighs at least 800 lbs. A 2 stroke Hirth pumped the air

to a

DOHC
engine whch was acting as a valve to feed the pipes. Definately an
impractical
power plant, but a study effort in converting combustion to detonation.
As stated - deflagration is the usual combustion process where flame
propagation
speeds are typically less than 100 ft/sec - Detonation (or "high order"
reactions)
have propagation rates measured in miles per second. Hydrogen is one of

the

fuels
that can convert well mixed combustion to detonation if confined under
appropriate
conditions. At Rocketdyne we used a detonation wave system to assure

near

simultaneous
ignition in multi chamber rocket engines (ie aerospike). Most combustion
experts
believe that the conversion  to thermal energy is no more effiucient in

a

detonation than
in more conventional combustion, it is just that pressure rises are more
rapid
frequently destroying hardware - No I do not think we can get any gain

in a

rotary
or any other shaft output combustion engine. The primary gain is in
hypersonic
flight - I maintain that the "supersonic combustion" in SCRAMJET has

never

been
demmonstrated . At hyper sonic speed, diffusing the inlet flow to

subsonic

for combustion
results in such a high temperature that fuels disasociate rather than

burn -

a reaction
that absorbs heat rather than release heat - for no propulsion. However,
with a detonation
you can release energy in a supersonic flow, and at least in theory make
thrust.
I think (and at least hope) that we have flown detonation engines in a
"black" program
but the devil remains in the details. This is probably a ripe area to

siphon

off some
Gov. money (as in this Vari EZ) right now.  Aren't you sorry you

asked?? -

Thomas y Reina Jakits wrote:

...you are not by any chance mistaken with the XCOR-Rocket-EZ?
http://www.xcor.com/ez.html

Thomas J.

I don't think so. This looks like no rocket engine you will ever see.
It looks more like a pipe organ.

Paul Lamar
 
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