Hard Light Productions Forums
Off-Topic Discussion => General Discussion => Topic started by: deep_eyes on January 29, 2005, 07:53:09 pm
-
http://www.pr.afrl.af.mil/divisions/prt/pde/Videos/longez/longez.html
By the US AIRFORCE.... hmmmm
-
Call me stupid, but what is it?
-
Oh, the Pulse Detonation engines...the idea is nothing new....the fact that it works now and not before is. I think its supposed to be fairly revolutionary like the jet was to the propller...or almost as much so. The big problem is noise...I wonder if they solved that yet.
-
Originally posted by Solatar
Call me stupid, but what is it?
Pulse Detonation. Think of it as a jet engine except that instead of a continuous stream of energy it creates little micro explosions. Thats the basics...there's more to it than that. I forget the details...but it equals more power.
-
Problem is, once they zoom out, it looks like they are demonstrating a really strong desk-fan..... :nervous:
-
Pulse jets were first used in the V1 missiles IIRC. 500,000 homes were destroyed by them in the UK during 1944....
-
That's what I was thinking of Clave. So if we had them in 1944 and then stopped using them why have we gone back to them?
-
Why would you spend gov fundings in useful stuff when you can do the same on things that looks cool?
[/sarcasm]
Seriously speaking, they might have found them useful for ultrasonic propulsion, or maybe improving afterburner efficency...
-
Read the ****ing page posted - most of your questions are answered.
Yes, the Germans built similar engines for the V1, however in those the fuel wasn't detonated, so it's efficency was ~5-10% of what a PDE would be capable of.
It's greatness if operating a lot more efficiently than turbofan engines (except for high bypass turbofan engines) even at high speeds - which is only achieveable with afterburners BTW so no wonder it's more efficient.
On the other hand I'm not convinced so far that mechanically this system would be just as reliable or cheap to run than a normal jet engine - though it DOES look promising.
Also note, that Ram- and Scramjets are still the way to go for higher speeds.
(http://www.pr.afrl.af.mil/divisions/prt/pde/PDE_FAQ/specimpulse.JPG)
This looks really promising.
http://en.wikipedia.org/wiki/Jet_engine
Wiki never lets you down.
EDIT - added diagram and lick to wikkipedia article.
-
Knew about this years ago when it came out in Popular Science.
-
Originally posted by karajorma
That's what I was thinking of Clave. So if we had them in 1944 and then stopped using them why have we gone back to them?
Pulsejets have been around since the1900s IIRC. A British invention I think...
This bloke (http://www.aardvark.co.nz/pjet/) has been messing about with pulsejets for years. Interesting little site he's got. Check it out...
-
Awesome stuff.
-
Tis good, but I can't help feeling that the money and research would be far better spent had they concentrated on moving away from Fossil-fuels.
-
Interesting... There's been talk about this in the conspiracy circles for a long time. Namely with the Aurora project using this engine. Theres even some footage of the contrails it's left behind, which look like donuts on a string because of the pulse detonations.
(http://www.aemann.pwp.blueyonder.co.uk/aircraft/black/aurora/images/contrail2.jpg)
Now I don't personally believe in the aurora project, but I do believe this engine or some sort of prototype has flown before.
-
The Aurora project? That was a strategic bomber, wasn't it? Or am I thinking of something else.....?
-
I believe there was an Aurora strategic bomber in development for the defense of the northern territories in the 1950s or so.
-
Aurora a hypersonic ubberplane that can circle the planet in three hours. suposedly it uses a PDE. it's suposed to be one of the realy cool (real) things to have come out of Area 51, if it exsists, wich it probly does in some form. the stealth fighter (f117) and bomber (B2) were other examples of stuff to have been developed at Nellis that "didn't exsist" wich leter turned out to be majorly important weapon systems.
-
Nellis would be a cool place to visit :p
Anyone remembers the old F19?
-
you mean this?
(http://www.fantastic-plastic.com/TESTORS%20F-19%20MAIN.jpg)
-
and while I'm posting,
the Aurora:
(http://www.geocities.com/Area51/Vault/9054/aurora1.jpg)
-
The Aurora looks a lot like the A12
-
wow. who would have thought that the US army could have developed an aircraft that was so poorly computer generated.
-
The Aurora or some equivalent probably exists since the US spends an awful lot of mone of scramjet development.
Scramjets are ramjet engines where the air passes through the engine without being slowed down to subsonic speeds, therefore it doesn't waste it's energy and gives of more thrust.
Ramjets are jet engines that have no moving parts - they only start working at roughly 2 machs. Instead a turbine it is the flow of air itself into the engine that compresses it.
The Aurora will probably use some scramjet engine, however since these only work on high speeds it will probably need a different type of engine for taking of a reaching cruising height - Pulse Detonation Engines are good candidate since their output is still good in the area where scramjets start to work.
-
It would be interesting to see if a turbofan engine could be made with blades that fold away so it could operate as a 'pure' ramjet...
Missiles with ramjets were pretty much my whole life at one time btw, I worked as an engineer servicing these for about 8 years:
http://www.picture-newsletter.com/missile/