External Fuel Burning Propulsion

cjchandler · 2006-09-23 08:15:30

I've run across various referances to external fuel buring propulsion, but I can't find a good discription of it. As far as I can tell it's a hypersonic propulsion system the burns the fuel on the outside of the craft's skin. Can any one explain it in any more detail and how it works? Thanks.

noosfractal · 2006-09-23 11:31:34

The first message in this discussion may be of assistance ...

http://www.netwrx1.com/skunk-works/v05.n109

cjchandler · 2006-09-23 13:39:34

Thanks, so instead of a cowl on it's scram jet it uses the boundary layer. Sounds cool, too bad it's inefficient. He said that all the first scram jets were like that, I wonder if they are easier to design or something? Seems all you'd need are fuel injectors and maybe a flame holder. Do you know what the geometry of the thing is?

noosfractal · 2006-09-23 15:16:39

fas.org talks of a "flaming pumpkin seed" ...

http://www.fas.org/irp/mystery/pde.htm

cjchandler · 2006-09-23 17:40:23

Thanks a lot noosfractal, you've answered a lot of my questions today. I saw that picture earlier but didn't have enough infromation to tell if they knew anything about what they were talking about. With a full body narrowing at the back it seems that this would work like an areospike rocket engine/nozzel. If so, I wonder why they didn't make a flat back on it, like a trunkated spike... Maybe for handling issues.

noosfractal · 2006-09-23 18:04:03

You're mose welcome. Yeah, maybe today it would look more like an X-43. I don't think they went far with external combustion before figuring out they could get better performance with a shroud.

publiusr · 2006-10-27 12:06:55

I wonder if anyone is doing work with RENE engines.

noosfractal · 2006-10-27 14:00:26

Work on ejectors for RBCC is mentioned in this doc ...

Hypersonics Project Reference Document
http://www.aero-space.nasa.gov/nra_pdf/ … sal_c1.pdf

cjchandler · 2006-10-28 19:22:25

Pardon my asking, but what is a RENE engine?

publiusr · 2006-12-08 15:33:35

Pardon my asking, but what is a RENE engine?

Example (not perfect)
http://www.astronautix.com/lvs/gnom.htm
Martin calculated in 1962 that the use of their Rocket Engine Nozzle Ejector system on the first stage of an orbital launcher would reduce total vehicle lift-off mass by 56% for the same net payload

Rocket Engine Nozzle Ejector (cone following an engine)

cjchandler · 2006-12-08 20:01:42

So it's simply a ramjet on the bottom of a rocket to help with the acceloration? That sounds so simple, why aren't these all over the place? I hate to think that people just forgot about them!

GCNRevenger · 2006-12-09 23:47:15

I'm sure there is a catch

cjchandler · 2006-12-12 05:33:51

Indeed, I looked on Wikipedia, and ramjet augmented rocket is basically the same thing. It says that the weight of the duct work ruined the gains in performance.

publiusr · 2006-12-22 15:51:08

Another materials revolution or two might change that...who can say.

cjchandler · 2006-12-23 17:10:32

Possibly, what I don't understand is why it says the areodynamics are so difficult, it's not too much different from a ramjet missle right? What I'd like to see is a sor of strap on booster ramjet augmented rocket out of some composite. It might help current boosters it it was cheap and self contained. You might even be able to sell it to altspace companies as the sole engine, since they won't go past mach 5 anyway.

publiusr · 2006-12-29 16:44:05

I've often wondered about an air-breathing solid like Gnom crossed with Sprint...

http://www.astronautix.com/lvs/sprint.htm
http://www.astronautix.com/lvs/gnom.htm

With Sprint being the intake cone.

I want Ares V for a bigger version of this--preferably with some kind of nuclear reactor or gas turbine engine
http://www.astronautix.com/craft/spalaser.htm

cjchandler · 2007-01-15 17:22:48

I was reading about Busemann's Biplane and was wondering if anyone has tried using this as the base for a scramjet engine, since the drag would be low. Is there any problem with this, besides of course, working at only one speed? Perhaps if after combustion the shock angle changed, the back of the engine could have a different angle than the front.

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#1 2006-09-23 08:15:30

Re: External Fuel Burning Propulsion

#2 2006-09-23 11:31:34

Re: External Fuel Burning Propulsion

#3 2006-09-23 13:39:34

Re: External Fuel Burning Propulsion

#4 2006-09-23 15:16:39

Re: External Fuel Burning Propulsion

#5 2006-09-23 17:40:23

Re: External Fuel Burning Propulsion

#6 2006-09-23 18:04:03

Re: External Fuel Burning Propulsion

#7 2006-10-27 12:06:55

Re: External Fuel Burning Propulsion

#8 2006-10-27 14:00:26

Re: External Fuel Burning Propulsion

#9 2006-10-28 19:22:25

Re: External Fuel Burning Propulsion

#10 2006-12-08 15:33:35

Re: External Fuel Burning Propulsion

#11 2006-12-08 20:01:42

Re: External Fuel Burning Propulsion

#12 2006-12-09 23:47:15

Re: External Fuel Burning Propulsion

#13 2006-12-12 05:33:51

Re: External Fuel Burning Propulsion

#14 2006-12-22 15:51:08

Re: External Fuel Burning Propulsion

#15 2006-12-23 17:10:32

Re: External Fuel Burning Propulsion

#16 2006-12-29 16:44:05

Re: External Fuel Burning Propulsion

#17 2007-01-15 17:22:48

Re: External Fuel Burning Propulsion

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