"For Sweden" (rallybeetle) 09/12/2013 at 14:05 • Filed to: Planelopnik, F-22 Raptor, F-22, Raptor, Lightning II

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AbigGRNboot > For Sweden 09/12/2013 at 14:06

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Every time you hear a bell ring....

willkinton247 > For Sweden 09/12/2013 at 14:13

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Here you go.

Osiris - I can haz Euro spec? > For Sweden 09/12/2013 at 14:15

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I love being able to see/hear these guys every day. One of the great things about living/working on an Air Force base. By the way, they are not nearly as loud as you'd think. C-130 is louder but the A-10 is definitely quieter.

DailyTurismo > For Sweden 09/12/2013 at 14:18

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Some may attempt to explain lift via Bernolli's principle

which is really just another form of an energy conservation equation for compressible flow, but to really understand why the air flows faster on the top side of the wing vs lower side you need to use the Kutta–Joukowski theorem

where

which describes the flow around a cylinder generating lift (L') based on velocity, density et cetera. However, I find the simplest version of lift is the one described by Euler in his derivation of Newton's 2nd law.

which essentially states that when fluid flow is curved there is a pressure differential orthogonal to the flow direction.

For Sweden > DailyTurismo 09/12/2013 at 14:24

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...he told the aerospace engineer...

DailyTurismo > For Sweden 09/12/2013 at 14:33

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Okay, let me translate into aerospace engineer-speak.

Here is this chart someone developed in the 1950s, this here is our design target, we'd update the charts but that would require FAA approval...

Hey what is this curve?

Err...I think that is a coffee stain...

Are you sure it isn't a cigarette burn?

Look, we used to use this chart developed by someone in the 1950s, but now we are replacing it with something much more modern and up-to-date, a fancy colored picture based finite difference model computer model developed by someone in the 1970s...its quite advanced.

BaconSandwich is tasty. > DailyTurismo 09/12/2013 at 15:18

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When you explain it that last way (generating a force orthogonal to the flow of direction), it actually makes more sense to me. Interesting.

ttyymmnn > DailyTurismo 09/12/2013 at 16:10

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DailyTurismo > ttyymmnn 09/12/2013 at 16:25

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You got a little something on your shirt...right there...no...there...

Chteelers > For Sweden 09/12/2013 at 17:24

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So at high-alpha, I'm assuming that's the flight control computer figuring out that it needed leading edge down, and both airlerons up? Fascinating how modern controls allow a much wider flight envelope.