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Air Force Builds Quiet Mach 6 Wind Tunnel
An anonymous reader writes "To help design 'scramjets' -- vehicles that'll travel thousands of miles per hour as they leave the atmosphere and zip around the globe -- the U.S. Air Force has just funded a wind tunnel that operates quietly at Mach 6. To get a quiet flow, the throat of the Mach 6 nozzle must be polished to a near-perfect mirror finish, eliminating roughness that would trip the flow."
Scramjets are one of the more interesting types of aircraft in research. I wouldn't mind seeing a link describing how it works :)
(Watch it ed up as an unmanned payload delivery system -_-;;)
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Can anybody with the right background tell me whether that's the case?
Initially I thought, wow! they will be able to test new aeroplanes in real conditions! No more depending on computer simulations of air flow. That's groundbreaking. But my realistic wife said: 'no way, thwy will not put REAL planes there'. So I checked in TFA:
The pipe is only 18 inches in diameter
So long, and thanks for the fish.
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That doesn't bode much good for the final airplane. I do not want to live near the (military) airport where that thing will take off.
My wife's sketchblog Blob[p]: Gastrono-me
do they mean quiet as in 130db compared to so loud it can set your hair on fire? thats the thing im wondering...
neat scramjet pictures here.
The theory of relativity doesn't work right in Arkansas.
We undergrads are the guineapigs of science, the people who do the things no one else wants to... all in exchange for $20. And we LIKE IT!
I'm generally "Interesting," "Insightful," and even "Funny" here. What the hell happens to me at parties?
Grad student 1: This job sucks.
Grad student 2 (turning on wind tunnel): No, it blows!
Thank you, I'll be here all day.
The Air Force is designing a quieter PC case? Replacing the 60mm or 80mm fans with 120mm fans should fix the fan noise problem. I think polishing the fan casing to mirror-like quality to reduce air drag is a bit of an overkill unless you like the polished chrome look.
TFA: that is the only one of its kind... and not the first of its kind....
nitpicking aside, my favorite part was that it's pricetag was under $1 million. if they're sharing their "how we did it" information (a big if since it's the USAF and boeing), scramjet research should take off in leaps and bounds given the cheapness of testing in a controlled environment, sans crashes, accidental or on-purpose.
The IRS is the one organization that you don't want to fuck with. Remember, these are the guys who took down Al Capone.
Computer Simulation can't help the project?
http://www.michel.eti.br
Thank goodness this "mirror" technology is all around us! I've always been an early tech adopter and there's even one on my bathroom wall. It's so smooth (almost has a "mirror finish") that I can actually rub my hand across it without detecting any roughness. It's exciting to know this is the same stuff the U.S. Air Force is using.
It said in the article that having these surfaces would greatly reduce the amount of heat that an aircraft recieves when returning to the atmosphere. And I was thinking, does that mean that one small tear could rip the aircraft apart, like the Columbia? It seems like it might be more beneficial to build craft that don't rip up like the space shuttle did, than craft that are even lighter.
Sure, but can it cool a Pentium 4?
(yes guys, we've still got a good three or four years of Intel bashing ahead of us seeing how the AMD socket-A bashing is still in progress.)
Executives at Gillette have announced the Mach 7 in response to Purdue's Mach 6 wind tunnel. "We simply cannot be outdone on Mach numbers."
When asked what the commercial for the Mach 7 will feature, the unnammed executive replied, "jet fighters, women, racecars, women, missiles, women, bullets...it will be more spectacular than watching the entire French airforce crash into a fireworks factory."
Please help metamoderate.
HA! And that dyson guy spent millions on his vaccum cleaner- and can it suck air at 4000mph+, NO!
This tunnel works in a fashion opposite most wind tunnels. Instead of pressurizing one end, they create a vacuum at the other. That means they only get a run time of 8 seconds, but they use computers to get all the data they need in that short of a time frame.
So, yeah, it really does suck.
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And I quote, " Scramjet technology is challenging because only limited testing can be performed in ground facilities." So, incredibly awsome. As it is operated by subsonic combustion of fuel in a stream of air compressed by the forward speed of the aircraft itself, as opposed to conventional turbojet engines, in which the compressor section (the fan blades) compresses the air. In comparison to turbojets, ramjets have no moving parts. And since this is a scramjet (supersonic-combustion ramjet) it would be double awsome to see them up, and running soonly.
Women- the final frontier...
As far as my background, I stayed at a Holiday Inn Express last night.
I assume that this is a USA-specific cultural reference intended as a joke. Can anyone please explain for those of us who are foreigners?
Stick Men
With 8 seconds they could do a lot more, like the effect of moving control surfaces on an aircraft model instead of just a scramjet engine test - the engine has no moving parts.
I read the Wikipedia article but didn't get something. If the engine only works at a minimum speed, how will we get a craft up to that speed? (1) Tow it or (2) give it two types of engines?
No sig for you!
With an 18" diameter pipe for such air to go through, and the student intern needed to enter it to clean/polish it, what first came to mind was someone turning it on to pull a more circumferentially challenged intern out.
:-)
And then I remembered the same scene in Charlie and the Chocolate factory (with Gene Wilder) and knew that it wasn't such a bad way to go.
From the end of the article with the picture:
"Eventually, scramjets may revolutionise air travel, allowing passenger aircraft to fly to London from Sydney in just two hours, making in-flight movies obsolete."
Remember, it's not a job, it's an indenture.
Do you see the sig? Do you have it in your sights? Why yes, Miss Moneypenny...
They're working on breaking wind quietly? What else is new?
First, air is pumped out of a large tank that is connected to one end of the wind tunnel, creating a vacuum inside the tank. Then a valve is opened between the tank and the wind tunnel, sucking a burst of air through the wind tunnel at high velocity. The short run time requires less expensive equipment, unlike the large compressors needed for other wind tunnels that pump air continuously.
I would have thought they could clean and polish by simply operating the thing, but no they have to do it with elbow grease. Remember that scene from the movie Heavy Metal, where aliens suck up two people from the Pentagon? That's one hell of a ride that ends with a bang.
It's nice to see them saving money, but we can only hope they don't send anyone in when the thing is primed.
Friends don't help friends install M$ junk.
Does it really need to be super smooth and mirror like?
I'm sure if it gave it a huge bonus in range, they would make golf balls with mirror finishes.
Perhaps we could dimple the surfaces of the tube...and achieve warp 1.
Really...or do dimples only work on spherical objects?
Who is this that even the wind and the waves obey Him? Surely this computer must submit also!
Also, the dimples mean that the ball reacts the opposite way to spin than a smooth ball would react. A smooth ball spinning clockwise will hook left due to lower pressure on it's left side due to the bernouli (sp?) effect. A dimpled ball will actualy experience higher pressure on that side and slice right.
This is why topspin is bad (on a drive) for a golfball cause you hit the dirt and loose distance.
"You saved 1968." - Ms. Valerie Pringle to the crew of Apollo 8
I read and thought "A million bucks? Is that all?" then I read it was 18" in diameter. Oh well.
They build a multi million dollar device and forget to build a gawddamn pipe cleaner...
Oh well, what the hell...
As I recall, there are already some very high power and large wind tunnels at the NASA Ames research center in Mountain View California. http://windtunnels.arc.nasa.gov/. For those of you that live in Silicon Valley, I'm sure you are all familiar with the gigantic wind tunnel that is large enouph to handle a complete mid-sized airliner.
Turns out it's just Steve Jobs talking into a sound-proof tube at MacWorld.
They hit 2 birds with one stone!
Its ok if the reynolds number (which is merely a ratio of the inertial forces to the viscous forces) is off a little bit... since the size of the model compared to the real craft is probably only an order of magnitude smaller, compared to many orders of magnitude larger than an atom, its inconsequential ... And actually it won't be off at all, in a modern wind tunnel it is calculated as a function of dynamic pressure , which will not vary.
Using the Pi theorem we can find nondimensional quantities. The quantities we measure in the test case will be the same for the real case.
-everphilski-
After all, they're trying not to trip the flow, yo.
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Anywhere the wind blows ...
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The Russians apparently lead the way in hypersonic missiles which are practically unstoppable while travelling at Mach4 or 5. The US is behind on this technology hence the rig...
spoonerize "magic trackpad"
"Despite the Pentagon's development of a new generation of hypersonic missile, the U.S. is still a decade behind Russia in high-speed cruise-missile design, according to defense analysts. According to the Defense Advanced Research Project Agency, the U.S. military is developing a new hypersonic robot missile reported to be capable of traveling in excess of six times the speed of sound and armed with its own miniature smart bombs. The new weapon, called the Advanced Rapid Response Missile Demonstrator, or ARRMD, is designed to cruise at over 4,000 miles an hour and strike targets hundreds of miles away in only a few seconds. "
Wow! This type of weapon would be a devastating weapon that could penetrate any defense system known today. A missile moving toward a target at 4,000 miles per hour would move so quickly through even the most sophisticated defense system that no computer could react quickly enough to shoot it down before it blew the targeted ship out of the water. Thank God we are working on it, and not the Russians and Chinese. Right? Wrong!!
"Nevertheless, defense analysts agree that the U.S. is fully a decade behind Russia in high-speed cruise missile designs. Russia currently deploys and exports the supersonic SS-N-22 Moskit cruise missile, NATO codenamed "Sunburn." The SS-N-22 is considered the most lethal anti-ship missile in the world, and flies at over 2.5 times the speed of sound only a few feet from the surface of the water." [This speed amounts to almost 1,700 miles per hour, or 28 miles per minute].
So Mach2.5 for the Russians right now, but they are still ahead.
spoonerize "magic trackpad"
FYI, the quiet Mach 6 wind tunnel was developed by the Purdue University School of Aeronautics and Astronautics and deserves credit / mention for it's development (would the same omission have occured if it was MIT that did something half as worthwhile?)
Go Boilers!
I like the bit where they talk about scramjets leaving the atmosphere as if they are going to remain in operation without air. How exactly does this work again? I thought scramjets required air to operate...
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When the space shuttle re-enters, it generates so much heat partly because it is intentionally flown belly-first to slow the thing down. Improving the aerodynamics of the craft and high speeds would cut down on heat generated, but also increase the stopping distance of such a craft to something rediculous, wouldn't it? Conservation of energy: the kinetic energy of the moving re-entry vehicle must be converted to some other kind of energy in order to stop, and there are not many options. Heat, crushing and melting of metal...
Besides that, the kind of sensitivity on the shape of the craft that the laminar flow would require would put the craft even more at the mercy of Murphy's law. The tiniest imperfection in the surface of such a craft could cause enough heating to melt a wing off, once the heat shielding is removed as "unnecessary."