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Old Jul 01, 2010, 03:24 PM
Flying Hazard
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Originally Posted by Jammo View Post
I guess if the flaps raised they would act as spoilers thus aiding high alpha maneuvers.
Don't think so, they would lessen the lift, the spoilers act as they do because they're in the middle of the wing increasing the distance the air has to travel over the wing. You don't get this result when raising flaps, nor slats.

For high Alpha they should be lowered. Look at the real ones!!
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Old Jul 01, 2010, 04:45 PM
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Real ones are, well real ones. They have their own rules. We dont have the mass that they struggle with. We get to fly with styro planes only

Raising the flaps gives you more high angle alpha, by losing some lift. With flaps you have more lift, and slower speed that would brake too much in high alpha, and youd face wing rock and stall possibly. Raising flaps you get more speed, higher alpha and less wing rock. Even though the air moves through high alpha wing, it gets less disrupted by recovering some of the air with spoilerons. Huge lift is not needed, since plane flies more with motors than wings.
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Old Jul 01, 2010, 06:37 PM
Flying Hazard
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Ok, I give you the point.

Well explained.
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Old Jul 01, 2010, 06:50 PM
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Originally Posted by SU-4ever View Post
Well explained.
Not well enough for me. I don't believe it yet . Can you please elaborate some more why raising flaps shall be a good idea in a high alpha flight condition?

Tx,
Henrik
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Old Jul 01, 2010, 06:53 PM
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Man those are some darn sexy pictures!

Danny
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Old Jul 01, 2010, 06:54 PM
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Originally Posted by hklagges View Post
hello,

just found this on china-direct-buy and alibaba. This seems to be the second version of the mig-29 from lanxiang.

Cheers,
henrik
mannn!!!!!!!!!!!!!!!!!!!!
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Old Jul 01, 2010, 06:57 PM
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Old Jul 01, 2010, 07:28 PM
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Originally Posted by jet-ster View Post
Man those are some darn sexy pictures!
So, opinion poll, which do you like more, the red or the grey version? I think the red one is more flashy, but a bit over the top, the grey one is classier.

Cheers,
Henrik
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Old Jul 01, 2010, 08:15 PM
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wa0! Hard to decide... ehmm both?
Maybe the Red One, don't know...

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Old Jul 01, 2010, 09:41 PM
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Originally Posted by kreot View Post
Real ones are, well real ones. They have their own rules. We dont have the mass that they struggle with. We get to fly with styro planes only

Raising the flaps gives you more high angle alpha, by losing some lift. With flaps you have more lift, and slower speed that would brake too much in high alpha, and youd face wing rock and stall possibly. Raising flaps you get more speed, higher alpha and less wing rock. Even though the air moves through high alpha wing, it gets less disrupted by recovering some of the air with spoilerons. Huge lift is not needed, since plane flies more with motors than wings.
Some of this doesn't make any sense. Even though we fly small Styrofoam the physics are still the same. If one were to raise both of the flaps rather than have them drop you are effectively ruining the camber of the wing, spoiling laminar flow, and causing a large amount of drag. Basically you are spoiling lift or creating spoilers. The drag caused is both induced from the low pressure created in the negative behind the flap (tumbling and turbulent airflow), and parasitic from its form. So all you would be doing is spoiling the lift that is much needed to keep your plane aloft at Vmca.

With flaps you are at least gaining some lift due to the change in chamber and chord. You are also creating drag which is something you would want if you want the aircraft to be flown behind the power curve in V-mca. So basically you want a ton of lift, a ton of power, and some drag to balance things. Not a ton of drag, no lift, and power.

It's all about balancing those 4 forces of flight.

Elevator effectiveness would work basically equally with spoilers or flaps. The issue isn't flowing laminar air towards the surface to make it more effective. The issue is allowing the plenty of "arm" or throw to counter-act tail down force. When at high angles of attack, the wings, especially in this configuration, would be blanking out the elevators quite a bit.
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Old Jul 01, 2010, 11:16 PM
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I like Flashy one for sure! Thats about the best looking foamie I have seen YET for me!
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Old Jul 01, 2010, 11:42 PM
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jdlilfan, I fly and kinda understand the whole flap thingie but what about the leading edge thingie do to the wing? what does it do?

Danny
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Old Jul 02, 2010, 12:44 AM
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Originally Posted by jet-ster View Post
jdlilfan, I fly and kinda understand the whole flap thingie but what about the leading edge thingie do to the wing? what does it do?

Danny
Although in this implementation, the lowered leading edge operates like this:

http://en.wikipedia.org/wiki/Leading_edge_cuff

I would imagine that when the leading edge is lowered, the airflow on the upper surface is less disturbed at high alpha, reducing stall speed.
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Old Jul 02, 2010, 01:40 AM
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Originally Posted by SU-4ever View Post
wa0! Hard to decide... ehmm both?
Very rational choice ! I agree with you, hehe...
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Old Jul 02, 2010, 07:04 AM
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Leading edge flaps, slats, slots, kruger flaps and many more leading edge devices all aid in lift, which lower stall speed. What you are doing is increasing the camber (curve) of the wing as well as lengthening the chord line. This generates a stronger area of low pressure (until a certain point). Low pressure above the wing=lift.

Most modern fighter jets feature these devices and most of them deploy automatically through fly by wire and computers when the aircraft is in high angles of attack, either from maneuvering or landing/ takeoff. The F-86 was the first jet aircraft to have them work automatically.
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