Successive blast compression for pulse detonation engine

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skyfrog
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Successive blast compression for pulse detonation engine

Post by skyfrog » Wed Sep 01, 2004 9:55 am

In my mind there's a concept engine incubating, this time not a pulsejet, but a pulse detonation engine, in which several annually arranged combustion chambers detonates once at a time, accumulated blast wave pressure pass on to the next one by successive detonation. Anyone interested ?
Long live jet engine !
Horace
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larry cottrill
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Re: Successive blast compression for pulse detonation engine

Post by larry cottrill » Wed Sep 01, 2004 12:09 pm

skyfrog wrote:In my mind there's a concept engine incubating, this time not a pulsejet, but a pulse detonation engine, in which several annually arranged combustion chambers detonates once at a time, accumulated blast wave pressure pass on to the next one by successive detonation. Anyone interested ?
Skyfrog -

I think this has been talked about before, perhaps in the old forums. It is interesting, but very hard to do.

The Germans in WWII had some kind of artillery weapon that used rings of explosive to accelerate the bullet as it traversed the length of the barrel. I am not much on history of artillery, so I have no idea whether this was just an experiment or a production weapon.

There are at least a couple of serious difficulties. When things are moving at sonic speeds, getting the charges to contribute their blasts at just the right time is really tough. But also, it seems to me that each charge will send a pressure wave not only out the pipe but back up the pipe in the forward direction as well, and the precise effect of each added pressure front would need to be carefully considered. And, each blast would alter the temperature and density of the gas remaining in the tube.

I dislike things like this -- it looks like a grand idea and just ends up being a big calculus problem. But, there's no reason it couldn't be done if the design approach is very thorough. Tough work, I think.

L Cottrill

NanoSoft
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Re: Successive blast compression for pulse detonation engine

Post by NanoSoft » Wed Sep 01, 2004 3:34 pm

Search trough

http://gltrs.grc.nasa.gov/ and
http://techreports.jpl.nasa.gov/ and
http://naca.larc.nasa.gov/

for PDE. Tons of documents on stuff ranging from ejector sizes to fuel. Very intersting concept indeed.

Nanosoft

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Re: Successive blast compression for pulse detonation engine

Post by yipster » Wed Sep 01, 2004 5:32 pm

Image http://www.worldwar.nl/secretweapons/secretgerman2.htm talks about some of the problems the germans found. before desert storm i recall oil pipes were stopped beeing exported to irak being intended for such a long range gun. the u.s. or canadian engineer named something like "bull" that claimed to have worked out the concept than was misteryously killed. i too was thinking for a halve underwater jet of something like "successive pulse detonation for a compression steam blast engine"

Mike Kirney
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Re: Successive blast compression for pulse detonation engine

Post by Mike Kirney » Wed Sep 01, 2004 8:18 pm

yipster wrote: before desert storm i recall oil pipes were stopped beeing exported to irak being intended for such a long range gun. the u.s. or canadian engineer named something like "bull" that claimed to have worked out the concept than was misteryously killed.
You are referring to Gerald Bull, born and raised in North Bay, Ontario, Canada. He was an engineer who specialized in gun-launched rockets. He designed and was building a giant cannon for Saddam Hussein in the 1980s when somebody (Israelis?) gunned him down in Belgium. The parts of the barrel were manufactured in England and exported as 'pipeline equipment' but MI6 found out about it and halted shipment, so his terror weapon never came to be fired.

http://www.pulse-jets.com/phpbb2/viewto ... light=#807
Trig IS fun.

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Re: Successive blast compression for pulse detonation engine

Post by Anthony » Wed Sep 01, 2004 9:21 pm

Mike Kirney wrote:
yipster wrote: before desert storm i recall oil pipes were stopped beeing exported to irak being intended for such a long range gun. the u.s. or canadian engineer named something like "bull" that claimed to have worked out the concept than was misteryously killed.
You are referring to Gerald Bull, born and raised in North Bay, Ontario, Canada. He was an engineer who specialized in gun-launched rockets. He designed and was building a giant cannon for Saddam Hussein in the 1980s when somebody (Israelis?) gunned him down in Belgium. The parts of the barrel were manufactured in England and exported as 'pipeline equipment' but MI6 found out about it and halted shipment, so his terror weapon never came to be fired.

http://www.pulse-jets.com/phpbb2/viewto ... light=#807
I would've been told to gun him down and would've had no remorse. Shameful how money sometimes drive people.

As for the German weapon, it looks like it's the V3, wich would have launched rocket artillery at England.
Anthony
Image

NanoSoft
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Re: Successive blast compression for pulse detonation engine

Post by NanoSoft » Thu Sep 02, 2004 2:43 am

I read about PDE's in a popsci magazine. Heres a link with very interesting pictures that show how complicated these engines are.

http://www.popsci.com/popsci/aviation/a ... -1,00.html

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Re: Successive blast compression for pulse detonation engine

Post by skyfrog » Thu Sep 02, 2004 4:16 am

Thanks guys for those useful weblinks and opinions.

The story of Gerald Bull's supergun had been moved to cinema, and I have seen it for at least 3 times. Just like the movie "Patton", I wouldn't get bored watching it again and again, this is really weird.

I have read from bruce simpson's website that PDE isn't for home builders due to the difficulty of construction and extreme dangerous of the high pressure. So this concept engine will at its best be a paper engine.
Long live jet engine !
Horace
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Post by Vermin » Fri Apr 27, 2007 3:26 pm

I would've been told to gun him down and would've had no remorse. Shameful how money sometimes drive people.
shameful how people condem and condone murder in the same breath. (just my opionion)
Vern
A desire to destroy as many man made hydrocarbon compounds as possible in one lifetime.

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