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no it was a shell.
"As I have already pointed out, the air force has already tested a scram jet shell. You said it yourself. It was the precursor to the 120mm scramshell version."
That was a missile.
http://www.arnold.af.mil/aedc/scramjet.htm
no it was a shell.
Originally Posted by Defcon 6
No the Af (and NASA) have tested the X-43. The ADT scramjet round is a DARPA project that was tested at the AF lab. The only test facility capable of doing that type of work.
SNiper, The reason I don't see scramjet rounds is the length required. Talos is a good example. As are various, mostly Russian, Ramjet missiles. You need a rocket booster to get it to Ramjet speed.
You will need the same to get it to Scramjet speeds. It will have to be a much bigger rocket. Especially since you are doing this from 0 speed at sealevel vice starting the booster at 20 thous feet from a moving plane and it climbing to 100 k.
This would make for an extremely long round that may cause tube troubles.
The newer series of 155 rounds (DPICM/RAP/825 smk) often hit the muzzle brake.
No big when dealing with 20 mile ranges, big deal when talking a couple of hundred miles.
RamJets are good to about Mach 5. Only bennie to scramjets is that they don't need to carry O2 for combustion.
Another thing that would have to be worked out is the temps that the projectile will be exposed to.
From NASA: When the second X-43A research vehicle flew Mach 6.83, or nearly seven times the speed of sound (the speed of sound is about 760 mph at sea level), the friction-generated 2600-degree Fahrenheit temperature on the leading edges of the vehicle's horizontal tails was more than enough to melt unprotected metal. Carbon-carbon thermal protection material kept them cool enough to withstand the searing heat. This is a challenge for even the most advanced thermal protection materials.
(And this was for less than 100 miles, how thich woild the protective coating have to be for a long range, USNFSA envisioned round?)
When the third and final X-43A flies in November, blistering temperatures created by the Mach 10 (7000 mph) speed will be in the neighborhood of 3600 degrees, the hotspot this time being the nose of the vehicle. The heat distribution is different this time around due to material differences. For further protection, Vehicle 3 will have additional thermal coatings on the horizontal tails' carbon-carbon leading edges.
Before we progress to a Scramjet round, I think we will have to crack the ramjet round nut.
A ramjet round would actually be a lot more complex because of the moving parts(ie spinning turbine sections).
A scramjet has none of that, just a fuel injector.
Snipe, a ramjet doesn't have any moving parts either. The only difference between a ram and scram jet is the air velocity at ignition.
You are thinking of a turbojet or turboramjet(as used on SR-71)
Last edited by Gun Grape; 27 Sep 05, at 02:04.
No the Af (and NASA) have tested the X-43. The ADT scramjet round is a DARPA project that was tested at the AF lab. The only test facility capable of doing that type of work.
The first-ever successful free flight of a hypersonic projectile powered by a supersonic combustion ramjet (scramjet) engine burning hydrocarbon fuel has been made at the Air Force’s Arnold Engineering Development Center, Arnold Air Force Base, Tenn. The test is an important step towards the realization of flight at hypersonic speeds.
On July 26, AEDC fired a hydrocarbon-fueled scramjet projectile developed by GASL Inc., of Ronkonkoma, N.Y and funded under contract to the Defense Advanced Research Projects Agency (DARPA).
The test was the second of two successful launches, the first occurring on June 20. Together, these tests demonstrate that scramjet engines will provide enough thrust to power a free-flying vehicle. The demonstration also identifies gun launch as a viable method for boosting scramjet vehicles to the hypersonic speeds at which they operate.
The tests used the Arnold Engineering Development Center’s two-stage light gas gun to accelerate the projectile to the flight condition through a 130-foot long gun barrel using 235 feet of an enclosed 1,000-foot ballistic range at a simulated altitude of 50,000.
The projectile experienced peak acceleration of approximately 10,000 Gs, and was launched from the gun at Mach 7.1. Arnold’s G-Range facility is the only range in the country capable of providing the low-acceleration loads required to launch the projectile. Then after the titanium projectile was launched, it used its scramjet engine to cover a distance of 260 feet in slightly over 30 milliseconds. The projectile is a four-inch diameter, 20-percent scale model of a conceptual missile.
Scramjet engines provide propulsion at speeds above Mach 5 by capturing atmospheric air to burn on-board fuel. These air-breathing engines are more efficient than rocket motors for hypersonic propulsion, and will ultimately allow the possibility of longer duration flight with greater payload.
Applications for such engines include powering long-range hypersonic missiles, gun-launched kinetic energy weapons, and access to space vehicles. In order to operate, scramjet engines must first be traveling at hypersonic speed. An accepted approach to reach scramjet take-over speeds is to attach the scramjet to a rocket booster as a first stage and then operate the scramjet once the rocket has increased the speed sufficiently. In the past, this boost method has proven risky and costly because rocket technology capable of reaching these speeds in the atmosphere can be complex. The DARPA program aimed to demonstrate gun launch as a low-cost alternative. DARPA anticipates that gun-launch flight-testing can reduce costs by one to two orders of magnitude, thereby accelerating the development of scramjet technology.
Additional launches at AEDC are planned, with higher performance scramjet engines and longer flight durations. GASL is performing the tests under a Phase II Small Business Innovation Research contract with DARPA.
AEDC is the nation’s premier aerospace ground flight simulation facility that is becoming known as America’s aerospace advantage. The center operates 58 test facilities at Arnold Air Force Base, Tenn. and at AEDC remote operating location, Hypervelocity Tunnel 9 in White Oak, Md. AEDC test facilities can simulate flight from sea level to 300 miles and speeds above MACH 16. Named after General of the Air Force Henry ‘Hap’ Arnold, AEDC was dedicated in 1951. Every high performance aircraft, missile, space launch system and most satellites operated by DoD today have been tested at AEDC. All NASA manned space systems have been tested at AEDC as well as many civilian aircraft designs and commercial jet engines.
No, it was a shell. Unless the X-whatever can be fired from a gun.
Didn't anyone have anything to say to this?
Hypersonic scramjet lab "Holod", made 5 successful flights from 1991 to 1998 and reached M=6.5 on a final test.The first-ever successful free flight of a hypersonic projectile powered by a supersonic combustion ramjet (scramjet) engine burning hydrocarbon fuel has been made at the Air Force’s Arnold Engineering Development Center, Arnold Air Force Base, Tenn.
Is the bottom one a gun fired projectile? because the one ontop sure isn't?
Both of them are pictures of the same craft. It's a missile.
Oh, the article I posted was about a gun fired shell. So it was indeed the first scramjet shell. But that missile is interesting. What do you think about BB's armed with 16" guns firing scram-shells? lol
I think it's an expensive idea.
Having a scramjet will means having targeting system also (Just to hit anything behind a horison).
So essentially that shell would be a missile. Missile that can survive a huge pressure in a gun barrel.
The main point of using a gun instead of missiles - is that they are CHEAP. This thing will not be cheap. Don't see a point of using it.
the ultimate reasoning behind it is greatly increased ammo capacity. A missile launcher fires, and is then empty. But a gun can be reloaded more easily. Also, a 16" gun turret can fire more ordinance at one time than a missile can carry.
Whatever happened to my opposition? I think GG gave up.
That looks more like a rocket then any screamjet I've seen, by definition don't screamjets need air intake somewhere?
As I understand it the only advantage of using a screamjet engine over a more convential rocket is you get more control over thrust/speed and more range. I beleive rockets are usually cheaper.
Last edited by canoe; 12 Dec 05, at 07:25.
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