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Cone-shaped screens attached to the intake of a jet engine should not only block entry of foreign material large enough to cause turbine damage; ie, birds, but also immediately deflect said materials off and from the screen so as not to disrupt the passage of air into the engine.
The conical shape of
the screen might also increase aero-dynamics or at least minimize air-intake reduction.
A very dashing C-130
http://badc.nerc.ac...a/mrf/c-130_big.gif Turkey kebabs, anyone? [coprocephalous, Feb 25 2009]
Examples
http://oopslist.com/ Search for "Bird" on page. [kamathln, Feb 26 2009]
[link]
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Aside from the getting-sucked-in problem, there's also
presumably a question of whether it would be strong enough
to deflect, say, a 1kg bird travelling at a relative speed of
500mph. |
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That entirely depends on the angle of impact, which depends on the lenght of the cone - and wouldn't jets look dashing with lances protruding far beyond the nose cone? |
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Actually, to protect the intakes of a jet engine, maybe you could mount large mincer blades, a bit like a C-130's on a forward extension of the turbine shaft, which would a) mince the pesky birds before they reach the intake AND b) give added thrust into the bargain. |
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Large collection baskets underneath would allow the recovery of the mince for in-flight catering purposes. |
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For sufficiently sharp cones , even an impact to the very center would not transfer much momentum. For a one meter intake diameter, i would envision, say, 20 meters of needletipped cone, shaped lifting-body style. Crosswinds might be detrimental, admittedly. |
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How fast are the planes going when birdstrike happens though? Assuming it's an airport-based problem (most of the rest of the time, the planes are flying too high up) AND since planes taking off or landing are (hopefully) at the slow-end of their operational speed range, then maybe some kind of retractable shielding might be appropriate - of course, I'm making all of this up, but how reasonable does that sound [21 Quest]? |
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//the plane wouldn't be able to takeoff in time and would
run off the end of the runway.// Yes, but apart from that? |
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I suspect the only way to protect against this kind of problem completely is an airfoil in front of the engine around which objects of a certain mass would be unable to navigate but that would not obstruct the ramming flow of air. On the scale of small engine manifolds such a curvature is imminently possible but at some loss of pressure, on the scale of a jet the losses may be unsuitable. This is a relatively rare problem and I'm not sure that a solution that decreased fuel economy would be worth the small decrease in rebuilding and passenger mortality. Such a restriction would be an invitation to icing and mechanical failure, problems that possibly pose a greater threat to the plane. I say keep the birds away from the runway through ecosystem engineering rather than trying to protect the plane in flight. |
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Glue birdseed to the plane but *behind* the engines, like near the tail. This would attract more birds to the plane but all safely out of reach. ("If you know where your enemies are, you are safer") |
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The way to avoid birdstrike is to put enough engines on the plane that you can lose one and still fly the plane. |
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Some stealth aircraft reduce their heat signatures by channeling the engine's exhaust to a large number of seperate ducts; perhaps something similar could be done for intake? |
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That is, a half dozen intake ducts join together to provide the engine's air... if a bird is sucked into any one of these ducts, it gets stuck there, while the other air ducts still provide enough air for the engine to breath. |
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Obviously, designing a duct which constricts enough to stop a bird, while not excessivly restricting airflow, will be a bit of a challenge. |
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How about having the bottom half of the engine casing slide forward and turn upwards. This would provide lift from oncoming air plus a small amount of extra lift as the engine sucks air down (technically the engine is lowering the air pressure in front of the fans and the atmosphere is pushing its way in). |
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Put fierce-looking cats in streamlined perspex boxes near the engines so the birds will be suitably deterred. |
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Make the whole plane look like a hawk ... |
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yeah.. like any bird would be able to see clearly objects zooming past at 500 miles an hour. |
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I'm guessing that the rotation of the jet turbine generates a significant electro-magnetic charge. Could this be used to power some sort of electric death ray-type affair mounted on the jet engine?Program it to obliterate anything directly in front of the engine intake (within effective range obviously) whilst the plane is in the air. |
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You can kill the bird with a death ray but its corpse will still nuke the engine. |
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I said 'obliterate' not kill. A suitably designed death ray should reduce the target to a number of much smaller and less dangerous components. It should also reduce the momentum of the incoming object. |
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The problem is not so much the 1kg of a bird hitting the compressor vanes, as bird is condiderably softer than compressor vane. The problem comes when the compressor vanes suddenly try to accelerate 1kg of anything substantially more dense and less elastic than air. |
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Perhaps the engine itself could be made mobile by affixing it to a rail or hydraulic piston of some sort. In this manner, a computer controlled early warning system utilizing a laser detection grid could be employed to quickly and temporarily move the engine away from the fuselage and out of the way when foreign objects are detected on a collision vector. But then I suppose that would be a jet engine protractor. |
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If you're gonna have a grid of lasers, why not make them full-strength and chop any incoming matter into small pieces? |
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// I said 'obliterate' not kill // [marked-for-tagline] |
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Because, my dear [Skrewloose], doing so would obliterate the pun. |
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What is the airspeed velocity of an unladen sparrow? |
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The answer to this problem is obviously, again, laser-triggered
automatic shotguns. The laser detects incoming birds just
before they enter the engine. The shotgun mounted next to
the engine goes off, blasting the bird sideways. It may carom
off the wing but its trajectory changes for the better. The
poorly aerodynamic shot slows quickly after leaving the gun,
and poses little risk to anything more than a few hundred
feet away. |
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