Air Force to Test Aeroelastic Wings

firegate writes "The New Scientist is reporting that the US Air Force is planning to test a variant of the Wing Warping steering system used on the original Wright Brothers plane to steer new supersonic jets. They've invested $41 million in the project so far, and the first test flight will take place next month at NASA's Dryden research center in California."

Comments

Test speeds.

[Jade E. 2]

From the article:

The technology will be tested at subsonic and supersonic speeds, though not in the unpredictable range close to the speed of sound.

Now, I'm no aerospace engineer, but how exactly do you test at supersonic speeds without at least passing through the range of speeds 'close to the speed of sound'? Or, if the wing snaps in half as it passes mach 1, do they just say "Oops, that didn't count, better not tell anyone."?

Re:Test speeds.

[Ma$$acre]

INAE either, but "passing through" and "[testing] in" are two different things. Going through the sonic barrier and testing within it are two different things. Going through is stressful... testing on the edge of mach 1 introduces amazing stresses. Something that flexes a lot more than a standard wing could set up harmonic vibrations which would shatter the hardware. Passing through would actually stablize after the initial shockwave.

Re:Test speeds.

[nihilvt]

It's extremely hard to test at supersonic speeds because supersonic wind tunnels are designed for a specific mach number. The geometry of the wind tunnel must be changed if a new supersonic mach speed is desired. Most supersonic wind tunnels have multiple test sections, each designed for a specific speed. Because of the nature of supersonic flow, the wind tunnel geometry must be "right" at each supersonic speed in order to ensure wave-free, "clean flow". Otherwise, any data collected is useless. As for testing at a sonic speed (mach = 1), that is extremely hard. The *only* place in a wind tunnel where the mach number can be one is at the throat (in a converging/diverging nozzle). Note that adding heat will always drive flow towards mach 1 (regardless of supersonic or subsonic flow). The only way to accelerate flow once it has reached mach one in a wind tunnel is a cross secional area increase. Wind tunnels are not developed so that one could place a test piece at the throat of the tunnel (I've never heard of one that is.)

More information on the subject...

[prisen]

I'm a USAF member, and at the office lately we've been tossing around this interesting subject. Honestly, the article presented in the story was pretty lame; here's a few good links we've come up with, if you want to know a bit more about the technology:

NASA Press Release
Air Force Research Laboratory brief
AAW photo collection (NASA)

wing warping...

[tanveer1979]

There is a very intersting applet about wing warping on NASA site.

Actually wing warping was discontinued due to the fact that as modern airplanes became bigger and heavier rigid Duralium(Aluminium+Copper) and steel was used, which was not very conductive to bending, But I guess with carbon fibre based materials that will change.

Wing warping gives a large degree of control. It is Demostrated very well in the java applet which shows the lift, the forces, the mechanics and the attitude on a model plane(like the one used by wright brothers).

A little history... and a further resource

[DaedalusLogic]

We are a little over a year away from the centennial of powered flight. The Wrights made their first successful powered flight on December 17th of 1903. The first run was something around 12 seconds... Later in the day they recorded durations of just short of 1 minute. The wing warping technique was used to control the roll of the airplane. The Europeans later developed the control surfaces known as ailerons to get around patents that the Wright Brothers had made on their wing warping technique. Ailerons eventually became the method of choice for future development for many engineering reasons.

An article on this matter was published and graces the cover of the September 2002 Aerospace America magazine. The plane this system is being tested on if not intended for is the F-18, the writer of the article was J.R. Wilson. Aerospace America page at AIAA.org

Re:Air Force Times

[kryonD]

Sorry to pop your bubble, but E-1 to E-4 pay ranges from $1022.70 to $1752.30 per month depending on time in service (dfas.mil). This is on top of the fact that all your food, housing, electricity, water, trash, medical, dental, and training are provided to you free of charge. In other words, the only financial obligations you have are the ones you create yourself. Even if you take a loan out on a car($300/mo. + $100/mo. for expensive insurance + $50/mo. for gas/upkeep), get a cell phone ($50/mo with a ton of minutes), and get cable plus wide-band access (up to $100/mo) that still leaves over $400 pure spending cash for even a boot E-1. Average promotion times are 6 mo. to E-2, 8 more mo. to E-3 and an average of 18 months for E-4 depending on how good of a worker you are. Most folks straight out of high school with little to no work experience usually don't have it nearly that good. Also, starting Oct 1st, the Military pays 100% tuition assistance for undergrad education, so free college to boot!

Now, that being said, the military is still a tad behind the civilian world in overall fiscal compensation. But it's a bit too far to say that enlisted make "almost nothing". As far as the IT field goes, most military people suck up the free training and bail after the 4 year stint for better paying jobs. This rapid attrition rate allows those that stay in to reach the ranks of E-5 and E-6 faster. Benefits begin to increase in the form of priviledges which makes staying in just about as worth while as getting out.

FYI, the daily unclassified, non-critical networks that the E-1 through E-4's usually administer have terrible up-time rates and is usually directly attributed to the lack of experience and education. Most of these self-proclaimed IT wizards couldn't manage a Nintendo without their roomate's assistance.

Before the blasting starts, I enlisted 9 years ago and have worked my way to the officer ranks. I think I made plenty of money then and make plenty of money now with the increase in pay directly related to the increase in my education level and responsibilities.