NationStates Jolt Archive

OK, I've got mixed feelings and info on SCRAMjets in Nationstates.

While I do think it would be cool to have SJ booster engines for fighter jets... how do you manage to get the aerodynamics right? I mean, sure, at first mention, scramjet tech seems simple enough to do so, and I've seen many people attempt to market them... just go fast enough and the supersonic airflow will begin to combust with a little fuel and all that. But there's just two big problems I see with this... if someone can answer these questions in a positive matter (pro, not con) then I might research scramjet boosters.

1st question is, I know the old RAMjet engines used to burn so hot that they used gallons and gallons of fuel per second... how much fuel would SCRAMjet use?

2nd, most important question is, Everything with a SCRAMjet in real life has some sort of crazy aerodynamically-special airframe to channel the air into the engine... how can a fighter jet, let alone a booster for a fighter jet, hold these special aerodynamic qualities?

Can someone please answer these for me please? I won't be -too- discouraged if someone just says "you can't have a SJ booster, it wouldn't work," but I just want to know, cuz I see many nations with that tech somehow (I'm guessing they pulled it from @$$-space), and many nations are bugging me to develop it.

What do you think?

Ok, I'm not sure about the first, the second isn't too hard.

Simply make a channel in the bottom of the bottom of the jet, not a jutting thing, just a channel from the bottom of the fighter, into the boosters. It's not too hard.

Ok, I'm not sure about the first, the second isn't too hard.

Simply make a channel in the bottom of the bottom of the jet, not a jutting thing, just a channel from the bottom of the fighter, into the boosters. It's not too hard.huh? Like a hole in the plane? Where would the boosters go? Are you talking about internal boosters or external boosters?

Can I -please- have a second opinion on this? Everything I've read so far says you need a big channel...

Well, all I can say is, SCRAMjets are expected to only be deployed in Missiles.

At this stage no military anywhere in the world sees them being placed on fighter jets in the near future. Well atleast no logical nation in the world.

Of course you will find some NASA experiment or something to prove me wrong, but when push comes to shove, they will not be used in combat planes for atleast 40 years.

Missiles, thats a different story, ramjets are already used in those.

Ramjets? Heh... Chellis prefers refined Pulse Jets for new age aircraft, and combat ready designs are already underway...

Ramjets? Heh... Chellis prefers refined Pulse Jets for new age aircraft, and combat ready designs are already underway...I said SCRAMjets...

Anyway, after doing a little more research, I found out that the aerodynamics part was only so that the thing didn't burn up or get ripped apart...

What I want to do is have an external scramjet booster pack, one that can clip onto a fighter jet, or even be permanently and aerodynamically mounted, and would engage for long-distance flights, like international reactions.

What do you guys think?

Well, here is some more info for you:

Air-Breathing Scramjet Engine Technologies

This challenging ground and flight-research program will expand significantly the boundaries of air-breathing flight by being the first to fly a "scramjet" powered aircraft at hypersonic speeds. Demonstrating the airframe-integrated ramjet/scramjet engine tops the list of program technology goals, followed by development of hypersonic aerodynamics and validation of design tools and test facilities for air-breathing hypersonic vehicles. The scramjet engine is the key enabling technology for this program. Without it, sustained hypersonic flight could prove impossible.

Ramjets operate by subsonic combustion of fuel in a stream of air compressed by the forward speed of the aircraft itself, as opposed to a normal jet engine, in which the compressor section (the compressor blades) compresses the air. Unlike jet engines, ramjets have no rotating parts. Ramjets operate from about Mach 2 to Mach 5.

Scramjets (supersonic-combustion ramjets) are ramjet engines in which the airflow through the whole engine remains supersonic. Scramjet technology is challenging because only limited testing can be performed in ground facilities. Long duration, full-scale testing requires flight research. Hyper-X will help build knowledge, confidence and a technology bridge to very high Mach number flight.

Currently, the world's fastest air-breathing aircraft, the SR-71, cruises slightly faster than Mach 3. The highest speed attained by NASA's rocket-powered X-15 was Mach 6.7. The X-43A aircraft is designed to fly faster than any previous air-breathing aircraft.

Conventional rocket engines are powered by mixing fuel with oxygen, both of which are traditionally carried onboard the aircraft. The Hyper-X vehicles, designated X-43A, carried only their fuel - hydrogen - while the oxygen needed to burn the fuel came from the atmosphere. By eliminating the need to carry oxygen aboard the aircraft, future hypersonic vehicles will have room to carry more payload. Another unique aspect of the X-43A vehicle is that the body of the aircraft itself forms critical elements of the engine, with the forebody acting as the intake for the airflow and the aft section serving as the nozzle. These technologies were to be put to the test during a rigorous flight-research program at NASA Dryden.

Now, the problem with putting them on fighter jets has to do with G-forces, and most importantly Pilot Reaction time. The plane would move so fast, far faster than the SR-71, which took several hundreds of miles just to deccelerate enough to enter a holding pattern for landing.

The SR-71 reaches upto Mach 3, and it is considered one of the world's most demanding and dangerous planes to fly...imagine it going Mach 6. Talk about a Widow-maker.

http://grin.hq.nasa.gov/IMAGES/SMALL/GPN-2000-000378.jpg

Here is a SCRAMjet, very primitive by standards today.

It's not scram if it is subsonic... Supersonic-Combustion RAMjet...

Either way, its not like we'd be maneuvering with these things, just closing distances.

It's not scram if it is subsonic... Supersonic-Combustion RAMjet...

Either way, its not like we'd be maneuvering with these things, just closing distances.

Yes, the above image is regarded by many as the first attempt to break the sound barrier. It was an experimental SCRAMjet, didn't work though, as we all know. The X series has that honor.

It's not scram if it is subsonic... Supersonic-Combustion RAMjet...

Either way, its not like we'd be maneuvering with these things, just closing distances.

Yes, the above image is regarded by many as the first attempt to break the sound barrier. It was an experimental SCRAMjet, didn't work though, as we all know. The X series has that honor.LOL dude, it can't be scram if it is subsonic... SCRAMs only combust at supersonice speeds, nto before... otherwise it'd just be called a RAMjet.

That picture is NOT a scramjet. A scramjet is a ramjet that is made to have everything happen at supersonic speeds. So far is RL only 1 has made postive thrust (able to accelarate itself).

Agrigento some of that information is wrong, ramjets work from about 400mph and over.

Reaction time is not important becuase as Raysia said it's for long cruise only(Not in combat area or near it) if the pilot doesn't have enough time to react to and enemy what is the chance that the enemy will? Basically 0.

G-Force isn't a problem again, scram and ram jet engine don't produce too much thrust so acceleration wouldn't be leading to low g-force levels. Ram and Scramjet engines are only cruise engines and nothing much else.

Raysia 1:Ramjets do have a large thurst specific fuel flow rate (TSFC) but because the actual thurst is low the total fuel flow is not too high(for cruising it's lower than a high bypass ratio turbofan)

2: Fighters shouldn't have ram or scramjets used on them becuase they experience hostile action much more than recon or bombers. Having a ram or scram jet sustainer on a fighter is not really needed.

IF you want to have a sustainer use a RAMJET.

Thank you very much... I think I'll stick with my Pulse-Det/Jet Hybrid engines for now... the real reason I asked was because my RF-11 fighters currently use a pair of auxilury Pulse-Detonation engines for long distance travel and short take off and quicker accel etc... and I was wondering what the chances were of switching those Aux engines out for SCRAMjets was. I'd assume SCRAMjets are pretty light weight compared to turbofans etc, and I would intend them for use in patrol craft and ranger craft. As you said, they almost use less fuel than normal engines, and yet put out a LOT more force for their size... so at the very least it could be a fuel saver for long trips, if not shortening the time with that ;)

EDIT: OH, and check out my new plane :)
http://www.nationstates.net/forum/viewtopic.php?t=103717

Raysia, this is what my nation has used for a long time. NASA (http://www.dfrc.nasa.gov/Research/HyperX/index.html) has been experementing a lot with it.

Raysia, this is what my nation has used for a long time. NASA (http://www.dfrc.nasa.gov/Research/HyperX/index.html) has been experementing a lot with it.Umm, yeah I know, that is why I asked ;)

I know people have been using it, but I wanted to know if it was realistic :P

Raysia, this is what my nation has used for a long time. NASA (http://www.dfrc.nasa.gov/Research/HyperX/index.html) has been experementing a lot with it.Umm, yeah I know, that is why I asked ;)

I know people have been using it, but I wanted to know if it was realistic :P

I'd say it is dude, it works. And has been perfected over the years, so who is to say that it wont work? :D . I used mine for space with a Hydrogen Oxygen drive, go for it i say. At the speed and height you will traveling, you wont be easy to shoot down 8)

Raysia, this is what my nation has used for a long time. NASA (http://www.dfrc.nasa.gov/Research/HyperX/index.html) has been experementing a lot with it.Umm, yeah I know, that is why I asked ;)

I know people have been using it, but I wanted to know if it was realistic :P

I'd say it is dude, it works. And has been perfected over the years, so who is to say that it wont work? :D . I used mine for space with a Hydrogen Oxygen drive, go for it i say. At the speed and height you will traveling, you wont be easy to shoot down 8)gah, you missed the question :P I asked if it was realistic to mount SCRAMjet boosters onto a plane, and if you need some special airframe, or if anything will do. But my question is answered, so nm :)

gah, you missed the question :P I asked if it was realistic to mount SCRAMjet boosters onto a plane, and if you need some special airframe, or if anything will do. But my question is answered, so nm :)

Ok *LOL* i'll never mind :P , but i'd say just to annoy you. Build a new plane thingo :D

gah, you missed the question :P I asked if it was realistic to mount SCRAMjet boosters onto a plane, and if you need some special airframe, or if anything will do. But my question is answered, so nm :)

Ok *LOL* i'll never mind :P , but i'd say just to annoy you. Build a new plane thingo :DHELLO: http://www.nationstates.net/forum/viewtopic.php?t=103717

sheesh...

check that out though, and bump it for me :)

gotta go to bed now, cya

My opinion is that this is all bullshit. Roleplay is BS, but its sometimes fun when done properly. Please nations, buy REAL military equipment. stuff that is on the market in real life. If I ever go to war again I will declare myself the winner if someone states that they have stuff that isn't real.

Are you some form of weed that comes out of nowhere? If you do not like it, ignore it, simple as that. No need to go cussing about it. Besides, this is technology that is possible in real life and has been thought of, thus it is real. Finally, if you declare yourself the winner in that situation, then you better expect to be ignored.

We use SCRAMJet FAST packs on high altitude interceptors. Basically, they put them on a ventral mount, and when you want to use them punch in what you want to close to, the computer takes over, and flies you there, and if necessary, will drop the booster for added manuverability. It's used on interceptors mainly, most on the SADC (Strategic Air Defense Command) wings that were stationed to intercept bombers that can carry nukes.
Kevin Land-Yeah, sure. Real military equipment. OK. Wuss. Afraid of the one thing that war drives? Technological advancement, genius.

I could see perhaps a SCRAMjet interceptor... but it wouldn't exactly be dogfight worthy because its aerodynamics would be driven by satisfying conditions for the SCRAMjet engine. I'd recommend sticking with the hybrid pulse-detonation engines.

I could see perhaps a SCRAMjet interceptor... but it wouldn't exactly be dogfight worthy because its aerodynamics would be driven by satisfying conditions for the SCRAMjet engine. I'd recommend sticking with the hybrid pulse-detonation engines.
Interceptors don't need to dogfight... fly into missile range, release a bunch of missiles, and go back.

I could see perhaps a SCRAMjet interceptor... but it wouldn't exactly be dogfight worthy because its aerodynamics would be driven by satisfying conditions for the SCRAMjet engine. I'd recommend sticking with the hybrid pulse-detonation engines.
Interceptors don't need to dogfight... fly into missile range, release a bunch of missiles, and go back.

Exactly.

What I was saying was that that plane was designed to be a SCRAMjet, it WASN'T though. Or atleast thats what NASA Dryden said. Guess they labelled it wrong.

Now, I doubt that any of that information is wrong, as I got it from www.globalsecurity.org. But then again, who knows.

Also, when I was at the Paris Airshow they had a big display on both Ram and SCRAMjets. According to them there is no fighter in current development for "Combat" that would be able to handle the stresses of a SCRAMjet and that the only application a SCRAMjet will have in the next 40 years will be on Reusable Space Ships, such as Hypersoars and on Missiles.


Now I must admit that I am certainly not strong in this area of information, but I think that is already obvious. Now my only point is that if NASA and other reputable institutions believe it is unuseable on Atmospheric Manned Aircraft, then I don't think it would work...but this is NS so c'est la vie.

And that was my other question...

Does the plane have to have a special shape for the scramjet to work? Or does it just havo be strong enough to hold the speed?

In order to withstand the thermal stresses and aerodynamic flows at hypersonic speed, yes, the airframe does have to be a special shape.

ACS, check t-grams

In order to withstand the thermal stresses and aerodynamic flows at hypersonic speed, yes, the airframe does have to be a special shape.Well, what if it only went, say, mach 4?

A SCRamjet fighter would be EXTREMELY useless, because it uses fuel like mad, so it would have something around 5 minute lifespan. I believe Japan made a SCRAMjet plane. It was called "Cherry Blossom", or something. It would be a sidewinder with a driver.

In order to withstand the thermal stresses and aerodynamic flows at hypersonic speed, yes, the airframe does have to be a special shape.Well, what if it only went, say, mach 4?

I believe that is actually too slow for a SCRAMjet to function.

A SCRamjet fighter would be EXTREMELY useless, because it uses fuel like mad, so it would have something around 5 minute lifespan. I believe Japan made a SCRAMjet plane. It was called "Cherry Blossom", or something. It would be a sidewinder with a driver.Umm, that other guy said SCRAMjets would use less fuel than most jet engines. Maybe you are thinking of RAMjets? There is a difference...

In order to withstand the thermal stresses and aerodynamic flows at hypersonic speed, yes, the airframe does have to be a special shape.Well, what if it only went, say, mach 4?

I believe that is actually too slow for a SCRAMjet to function.Really? It says supersonic combustion, that denotes that at supersonic speeds, it would kick in. The fighter I am planning to put this on can reach mach 3 on its own.

If I remember correctly, the operating range of SCRAMjets is Mach 5+

In order to withstand the thermal stresses and aerodynamic flows at hypersonic speed, yes, the airframe does have to be a special shape.Well, what if it only went, say, mach 4?

I believe that is actually too slow for a SCRAMjet to function.

Yes Mach4 is too slow:

OOC:Scramjet is an acronym for Supersonic Combustion Ramjet. The scramjet differs from the ramjet in that combustion takes place at supersonic air velocities through the engine. It is mechanically simple, but vastly more complex aerodynamically than a jet engine.

The Sambizie Areospace Division has completed the final testing and development of the SCRAMjet. Test resulted in the decesion being made to use Helium (HE3) as the best type of "injector-fuel" for the SCRAMjet. Due to the combustion needed during supersonic airflow, Helium is the needed source.

The scramjet grabs most of its fuel from the air it rushes through. Mechanically simple - it has no moving parts - it has proved very tricky to develop, chiefly because it only starts to work at speeds above Mach 5.

CONSEPTUAL TEST RESULTS:
Actual NASA Test Results
The test was of a 10-centimetre- (four-inch) diameter, 20% model of a conceptual missile fired from a gun. The projectile experienced a peak acceleration of approximately 10,000 Gs, and emerged from the gun at Mach 7. After the titanium projectile was launched, it used its scramjet to cover a distance of 80 metres (260 feet) in slightly over 30 milliseconds.
Scramjet engines provide propulsion at speeds above Mach 5 by capturing atmospheric air to mix with on-board fuel. These air-breathing engines are therefore more efficient than conventional rocket motors because they do not need to carry an oxidant with them.

We have proven these test to be succesful and have started the manufacturing of the SCRAMjet. Due to the fuel used, Helium (HE3), the engine has been named: He3-SCRAMjet.

He3-SCRAMjet:
http://www.g2mil.com/scramjet.jpg

Ok, we all know in reality the G's and structual engineering would be "near" impossible. However, this is NS and anything is possible :lol:
In RL, SCRAMjets are much more practical for missiles...not planes. We use SCRAMjets for our SA-43 Hammerheads...but again, these are Transatmospheric Endo Exo Fighters...not RL.

Rysia, hope this helps...if you have any questions feel free to ask away.

Umm, so how is mach 4 too slow? As far as I know, Mach 4 is well supersonic... mach 5 and above is hypersonic... if it needed to be at mach 5 to combust, they would not have called it SUPERsonic.

Like I said, if I remember correctly, a SCRAMjet engine will not operate below speeds of Mach 5... thus the big rocket boosters that all current designs ride on.

Umm, so how is mach 4 too slow? As far as I know, Mach 4 is well supersonic... mach 5 and above is hypersonic... if it needed to be at mach 5 to combust, they would not have called it SUPERsonic.

Mach 4 is Supersonic, but the whole point of SCRAMjets is to reach Hypersonic speeds. Its a waste to use it for Mach 4.

Umm, so how is mach 4 too slow? As far as I know, Mach 4 is well supersonic... mach 5 and above is hypersonic... if it needed to be at mach 5 to combust, they would not have called it SUPERsonic.

Hmmm, don't know...Good question, but then again I didn't give it the acronymn...NASA did...lol.

Umm, so how is mach 4 too slow? As far as I know, Mach 4 is well supersonic... mach 5 and above is hypersonic... if it needed to be at mach 5 to combust, they would not have called it SUPERsonic.

Hmmm, don't know...Good question, but then again I didn't give it the acronymn...NASA did...lol.

Raysia, the S in SCRAMjet does indeed stand for 'supersonic'. However, this denotes the speed of the reactants through the engine itself. Normal RAMjets often move at supersonic speeds; however, they are not SCRAMjets because the fuel/air mixture is not moving at supersonic speeds through the engine itself.

Hope that helped.

my RF-11 fighters currently use a pair of auxilury Pulse-Detonation engines for long distance travel

Pulse-detonation CANNOT be used for long distance travel, because they explode a large amount of fuel at the same time in a small area extremlyt quickly the metal would not be able to stand the stress of long distance travel in pulse detontation.

my RF-11 fighters currently use a pair of auxilury Pulse-Detonation engines for long distance travel

Pulse-detonation CANNOT be used for long distance travel, because they explode a large amount of fuel at the same time in a small area extremlyt quickly the metal would not be able to stand the stress of long distance travel in pulse detontation.Hmm, I did not know that... That's why we use hybrids. The Pulse dets are just for added kick every now and then.

my RF-11 fighters currently use a pair of auxilury Pulse-Detonation engines for long distance travel

Pulse-detonation CANNOT be used for long distance travel, because they explode a large amount of fuel at the same time in a small area extremlyt quickly the metal would not be able to stand the stress of long distance travel in pulse detontation.

Actually, both GE and Pratt & Whitney are developing hybrid PDEs that use the bypass air from turbofans to feed into small PD chambers to improve efficiency... so, those could be used over long-ranges.

http://www.g2mil.com/scramjet.jpg

I've seen that pic.. and have copyrighted 16-inch scramjet projectiles which are fired from my battleships' main guns.

God bless,

The Republic of Syskeyia