Blackbird
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MiG-29/Su-27 Aerodynamic Question

Fri Sep 12, 2008 2:38 am

The MiG-29 and Su-27, like the F-14 have a wide spacing between the engines forming a lifting-surface known as a tunnel (or in the F-14's case, a pancake) which adds additional lifting area to the plane over just that of the wings.

How much extra lifting-area does the MiG-29 and Su-27's tunnels add in addition to the lifting area of the wings?


BTW: As an interesting note, the F-14's tunnel/pancake adds 443 extra square feet of wing-area (which is actually greater than the entire wing-area of the F-100, or F-8) which is almost that of the wings themselves, at 565 square-feet, which equate to a total lifting area of 1,008 square feet!


Blackbird
 
sovietjet
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RE: MiG-29/Su-27 Aerodynamic Question

Fri Sep 12, 2008 6:20 am

Blackbird, you're killing us with these detailed technical questions  Smile . I will try to find out for you but it's a rather challenging task.
 
Blackbird
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RE: MiG-29/Su-27 Aerodynamic Question

Fri Sep 12, 2008 7:06 pm

Sovietjet,

Quote:
Blackbird, you're killing us with these detailed technical questions  Smile . I will try to find out for you but it's a rather challenging task.

Thank you for your assistance -- My apologies, by the way, about all the questions (especially with the rapid frequency in which I've asked them).


Blackbird
 
prebennorholm
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RE: MiG-29/Su-27 Aerodynamic Question

Fri Sep 19, 2008 12:01 am

Dear Blackbird, wingspan is a much more efficient lift generator than area.

The reason for the quite widely spaced engines is to make room for a lot of internal fuel near the center of gravity of the plane. At a place which is already seriously obstructed by the landing gear wells.

The area between the engines does produce lift at high angle of attack. But not nearly as efficiently per square foot as the wing.
Always keep your number of landings equal to your number of take-offs
 
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Loran
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RE: MiG-29/Su-27 Aerodynamic Question

Fri Sep 26, 2008 12:16 pm

AFAIK this is also a safety feature in case of engine fire, particularly important for naval aircraft.

Loran
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mandala499
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RE: MiG-29/Su-27 Aerodynamic Question

Sat Oct 04, 2008 7:47 pm



Quoting Prebennorholm (Reply 3):
The area between the engines does produce lift at high angle of attack. But not nearly as efficiently per square foot as the wing.

Let's not forget that it adds drag too to have a large surface area between the engines...

Mandala499
When losing situational awareness, pray Cumulus Granitus isn't nearby !
 
Blackbird
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RE: MiG-29/Su-27 Aerodynamic Question

Sat Oct 04, 2008 8:51 pm

Prebennorholm,

Quote:
Dear Blackbird, wingspan is a much more efficient lift generator than area.

The reason for the quite widely spaced engines is to make room for a lot of internal fuel near the center of gravity of the plane. At a place which is already seriously obstructed by the landing gear wells.

The area between the engines does produce lift at high angle of attack. But not nearly as efficiently per square foot as the wing.

I just wanted to know for statistical purposes what the area of the pancake/tunnel area was. As I said, I know what the pancake/tunnel area is for the F-14 (443 square feet) -- I, however, do not know the surface area of the MiG-29 and Su-27's tunnel/pancake


Blackbird

[Edited 2008-10-04 13:52:32]
 
ferrypilot
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RE: MiG-29/Su-27 Aerodynamic Question

Mon Oct 13, 2008 2:35 am



Quoting Sovietjet (Reply 1):
Blackbird, you're killing us with these detailed technical questions Smile . I will try to find out for you but it's a rather challenging task.

...Can't refuse a lady eh!  Smile
 
Jackonicko
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RE: MiG-29/Su-27 Aerodynamic Question

Mon Oct 13, 2008 10:50 am

Don't make the mistake of assuming that 1m2 between the engines gives the same lift as 1m2 on the wing area.

Back in 1988, when the MiG-29 made its Farnborough debut, Valery Menitsky estimated that the tunnel added "somewhere between 10 and 20%" to overall lift."

As MiG's then Chief Test Pilot, I believed him!
 
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ptrjong
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RE: MiG-29/Su-27 Aerodynamic Question

Mon Oct 13, 2008 12:37 pm



Quoting Blackbird (Reply 6):
I just wanted to know for statistical purposes what the area of the pancake/tunnel area was. As I said, I know what the pancake/tunnel area is for the F-14 (443 square feet) -- I, however, do not know the surface area of the MiG-29 and Su-27's tunnel/pancake

Yesterday you think Russia is going to launch a Tu-160 attack against the US from Venezuela, and today you think it is such an open society that the exact dimensions of the bottom parts of the MiG-29 and Su-27 are public information?

You ought to travel a bit.

Peter Smile
The only difference between me and a madman is that I am not mad (Salvador Dali)
 
johns624
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RE: MiG-29/Su-27 Aerodynamic Question

Mon Oct 13, 2008 1:02 pm



Quoting Ptrjong (Reply 9):
Yesterday you think Russia is going to launch a Tu-160 attack against the US from Venezuela, and today you think it is such an open society that the exact dimensions of the bottom parts of the MiG-29 and Su-27 are public information?

I don't understand how some people on this forum can be so interested in military aircarft while at the same time be so anti-military. This hardware was NOT produced to look cool or entertain you but to further its country's aims and goals and (get this) kill people and fight wars...
 
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ptrjong
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RE: MiG-29/Su-27 Aerodynamic Question

Mon Oct 13, 2008 1:25 pm



Quoting Johns624 (Reply 10):

And how does this relate to what I said?
The only difference between me and a madman is that I am not mad (Salvador Dali)
 
johns624
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RE: MiG-29/Su-27 Aerodynamic Question

Mon Oct 13, 2008 1:52 pm



Quoting Ptrjong (Reply 11):
And how does this relate to what I said?

I was agreeing with you that some members are living in their own little, happy world.
 
Blackbird
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RE: MiG-29/Su-27 Aerodynamic Question

Mon Oct 13, 2008 8:16 pm

Johns624,

I know exactly what the purpose of a military aircraft is designed for -- shoot down opposing countries planes, and bomb the living snot out of a variety of ground targets (which can include boats, and ships).


Blackbird

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