Pulse Detonation Engines (PDE's)

On Tue, 09 Mar 2004 20:14:12 +1300, Bruce Simpson
wrote:

On 6 Mar 2004 18:07:31 -0800, (Eric Moore)
wrote:

Bruce Simpson wrote in message . ..
On 29 Feb 2004 18:57:36 -0800, (Eric Moore)
wrote:

If this PDE research pans out, what would such an engine be used on?

A high-speed, high-altitude cruise missile (Something like FastHawk or
ARRMD)?

An SR-71 replacement (possibly manned, but probably not)?

The first stage of a two stage reusuable space launch system?

Something else?

There are significant problems to using PDEs as a propulsive source.
The magnitude of the shockwaves produced is extremely high as are the
levels of vibration.


If it can't be used as a propulsive source, then what CAN it be used for?

Right now -- not very much, if the published results are anything to
go by :-)

However, once they get the technology sorted I suspect the most common
application will be for hypersonic pilotless vehicles such as missiles
or as an air-breathing first-stage for low-cost re-usable low-earth
orbit or sub-orbital vehicles.


given time and the technology... what would you asy is the chances of
a pulse jet space shuttle?

pulse jet in the atmosphere using air... and when reaching high enough
altitudes... closing a valve in the engine so the rear combustion
chamber is isolated and then injecting oxidiser with the fuel...
converting the airbreathing Pulse jet to a rocket...

(Eric Moore) writes:


If it can't be used as a propulsive source, then what CAN it be used for?


Scaring away potential neighbors.
--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

The PDE technique offers one solution to the problem of hypersonic
thrust - burning the fuel-air mix in the millisecond or so of time
available. Consider the fact that the fuel-air mix has to combust and
go through the engine faster than the vehicle is moving or the
incoming air just piles up and you don't get any thrust. A rocket
doesn't have this problem. Detonation occurs much faster than
combustion - and if the duct is acoustically resonant (there's a nice
problem with changing velocities!) the engine will be maximally
efficient. Even if it never flies it'd be a good addition to a rock
concert.
Walt BJ