J-20 5th Gen Fighter Thread V

[Air Force Brat]

Not knowing what the actual angle of attack really is in that particular moment, I believe it's still likely that the canards, while having a negative angle of incidence here, do have a (slightly) positive angle of attack. And therefore also / mainly contribute to a continued pitching moment?
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After some study, you may be and are quite likely right, I was rather thrilled when I read this at first, because I was certain that of your gazillian or so posts you had finally made a boo-boo?, but well "KRAP" yes that is Tuetonic for "stuff", you are prolly right again. Not that I want you to be wrong or anything, maybe just a little "human"??? I believe the Eng has corrected me on that before?? sorry Eng, I am a slow learner??? but once again I can exclaim, "if only I could see some "blue smoke" from the wind-tunnel testing on this bird?

I would add that the "PHOON" has recently sprouted delta shaped "strakes" beneath the cockpit on both sides that "help" it between 25-35 degrees angle of attack, how bout you doing a little research, and reporting back to us on their function, and posting it on the aerodynamics thread???

 

[Ultra]

I don't know what are the things that looked like two hexagons joined together, but the rhombus shaped "hole" just in front of the cockpit is probably aperture for the EODAS. I think it was actually discussed here before and others have pointed out other possible places.

Actually I wonder if the two larger black thing on the back centre of the plane between the two engines are the intake and exhaust for generators that start the engines (Jet fuel starter or auxiliary power unit). 2001 and 2002 have them on the bottom but perhaps due to the weapon bay being loaded from the bottom they decided it could be better to have those on the top?

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You can see prototype 2001 with APU on the bottom side start its engines here:

Does anyone know where F-22's APU intake and exhaust is situated?

Pretty sure those are the EO-DAS apertures similar to F-35.
DAS Apertures are at the same locations as J-20.

 

[Ultra]

I don't think these has been posted. The 2015 underside looks beautiful.

 

[no_name]

Nice details there, not as large as 2012 but you can make out the serrated pattern of the canard trailing edge on the 2015. I wonder if the light 'strip' convering the edges of the canard are of radar absorbing material?

The leading edge flap have those segmented parts, maybe they are places to put further array band in, like the F-35? Or they could also be RAM.

 

[Scratch]

After some study, you may be and are quite likely right, I was rather thrilled when I read this at first, because I was certain that of your gazillian or so posts you had finally made a boo-boo?, but well "KRAP" yes that is Tuetonic for "stuff", you are prolly right again.

Just been rethinking what I was telling here before. I think delta designs, especially those with relaxed stability, tend to experiance a shift of the center of pressure under high AoA. This may cause further pitch-up. As such, at least to break that high AoA condition, a pitch down moment (negative AoA) may be required to return to straight flight. Therefore, maybe throughout, or at least when ending a turn, the canards may indeed have a negative AoA.

 

[Air Force Brat]

Just been rethinking what I was telling here before. I think delta designs, especially those with relaxed stability, tend to experiance a shift of the center of pressure under high AoA. This may cause further pitch-up. As such, at least to break that high AoA condition, a pitch down moment (negative AoA) may be required to return to straight flight. Therefore, maybe throughout, or at least when ending a turn, the canards may indeed have a negative AoA.

Now here gentlemen, we have A+ work by master Scratch, he has used his thinking cap not just to answer the question to my satisfaction, but upon further reflection, has come back with a much more accurate answer! In fact Dr. Song stated for the record that the J-20 MUST be able to recover from high alpha, post stall maneuvering----"whether or not it has thrust vectoring"? the only way to achieve that is to enable the canards to have a very large deflection both upward and downward, in addition to the "distant coupling" of his canard design.
Thank you master Scratch, your integrity is as impeccable as the rest of your thinking, you would make a very fine pilot! you should be in those "Phoons"!

 

[Ultra]

I don't think this has been posted...

 

[lllchairmanlll]

 

[Air Force Brat]

Now that is more like it, "turn and burn baby, turn and burn", almost looks like setup for some airshow occurring somewhere, but there is no mistaking the pride and joy in that "citizens" voice and the excitement being created by the J-20, my own little brothers several low passes in his own aircraft were almost as exciting to myself and my neighbors, and way lower! woo-hoo, even the Honey-Badger stated for the first time, that looks like fun!

let me state it once again for our noo-BBBs, this aircraft flys "very well", very well indeed!"

 

[SpicySichuan]

Whoever came up with the flight plan above that area is kind of a jerk. I feel bad for the car owners and their employees at the Geely and Ford factories.