(Frode Hansen) wrote in message . com...
NoHoverStop wrote in message ...
Franz Geff wrote:
Has any other country had success with a Ramjet or Scramjet???

Depends what you mean by "success"; no-one's flying them commercially
yet. However: http://www.abc.net.au/science/slab/hyshot/default.htm

The story that they succesfully flight tested a scramjet seems to be
well accepted, but are the test data peer rewieved and the scientific
community in agreement with this conclusion?

I am also wondering if there exist any conseptual ideas for useful
application of such an engine . I imagine one would need considerable
boosting just to get a vehicle from 'runay mode' and into 'working
mode', and that the prices of the once so impressive Concorde flights
would be dwarfed by orders of magnitude if passenger/payload traffic
is considered.

I like it though. No moving parts :-)

.fh

Most of the schemes rely on the device opperating as a ramjet and then
changing the Geometry from ramjet to scramjet mode as speed excedes
about Mach 4.5 -Mach 5.5.

There is a type of ramjet called an inductor ramjet. This has a small
rocket motor in the central supersonic diffuser spike. Below
opperating speed the rocket fires producing a small amount of thrust
but also inducing an airflow sufficient to opperate as a ramjet at
zero speed. Specific impulse when the Germans tested it in the
1930/1940 is about 800 which is about twice that of a LOH/LOX rocket
but half that of a turbofan with reheat. (At that time they were
interested in rockets to get started and coal dust as fuel)

These tests seem to be have an redculouse aura of PR hype. Everything
from the synthetic and hysterionic whooping in the control center to
the schmaltzy hypersonic airliners cartoons. The only use for this
will be putting loads into orbit.

X43 is trying to do a few other things. It is trying to integrate the
forbody of the vehicle as part of the scramjet intake i.e
precompression and the afterbody of the vehicle as the engine nozzle
while also making the body a lifting body. It's all tall order to
integrate all three but they have to be integrated because scramjets
just don't work well enough on their own. The wedge shapped nose has
to be agressively cooled by hydrogen.

Personaly I think a two stage to orbit vehicle with a 100% reusable
flyback booster is a better direction to go.