J-20... The New Generation Fighter II

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MiG-29

Banned Idiot
First, J-20's wings have higher swap angle. It has less drag than F-22 when going straight (more drag when turning).

It has smaller vertical stabilizers (40% smaller). That's less drag and weight.

Based on public published papers by Chengdu designers, the delta/lifting body/canard configuration generates 80% more lift than delta only.

There is also unconfirmed rumor that J-20 has full control with the main wings only without canards. That means at high speed, it can use wing flaps to control, instead of canards.

So, while at a glance, J-22 has a large body. It comes down to whether the additional weight is canceled out by the much smaller vertical stabilizers. It may still be heavier, but I doubt the difference is that big. Remember J-8B (which does not use any modern materials) is 21m long, but only 9ton+ empty.

On lift, I am pretty sure J-22 has better lift than F-22.

On drag, I would call them even. Again, the additional drag created by longer body is canceled out by smaller vertical stabilizers.

a wing with more sweep will generate less drag at higher speed but will have less ability for AoA handling, the J-20 has smaller vertical dorsal stabilizers but it has two extra ventral fins thus increasing drag, by the position of the wing, the main landing gear is ahead of the main aerodynamic center, and center of lift, thus the center of gravity of the J-20 is quit ahead of the wing, as in the case of the AJ-37 the canard bears more weight and needs to generate more lift reducing its AoA and its deflection, the canard is a lifting canard in the J-20, all aircraft with canards can use flaps instead of canards for trimming, however the use of flaps or vertical tail for trimming means extra drag.
this configuration makes for a more stable aircraft which means a nose heavy aircraft.

The J-8II does not use internal weapons bays neither canted bodyside fuselage chines, stealth aircraft are heavier always than conventional aircraft, also one of the claims of the J-20 longer fuselage is to hold more weapons and fuel, so it is unlikely it is lighter than the F-22
 
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i.e.

Senior Member
well you will need to prove the rear cross section of the aft fuselage of the J-20 is narrower than the F-22`s specially when the widest part of the wing of the J-20 is at the aft of the aircraft, longer fuselages also generate more boundary layer thus drag is higher

I marvel at your ability to perform wind-tunnel and/or CFD test with eyeballs.

btw, this year's AIAA Conference on Fluid Dynamics in Honalulu? you coming?
 
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MiG-29

Banned Idiot
I marvel at your ability to perform wind-tunnel and/or CFD test with eyeballs.
you must be a national treasure or something like that.

btw, this year's AIAA Conference on Fluid Dynamics in Honalulu? you coming?

of course you can not prove the J-20 is narrower, so now you turn into the no one knows however the J-20 is better than the F-22, prove that the J-20 has narrower rear fuselage with less drag even it is longer, however i will give some data that will open your eyes, the F-35 had several design configurations, canard wing, canard wing and tailplane and wing tailplane configuration were tested, you know what they did discover? supersonic trim drag and drag in general are equal in aircraft having same wing size and shape, unstable static stability and canard or tailplanes.

Ask your self why the F-22 and F-35 have no canards? less agility? since you think having canards give better drag seems you know nothing, do you know why fighter aircraft with canards use delta wings like the J-10 or Gripen ? why the F-35 does not use a delta wing but uses tailplanes?
delta wings have less drag but canards generate more drag, trapezoidal wings have less drag but tailplanes generate less drag due to a wake downwash away from the main wing.
Thus a F-35 can use a trapezoidal wing, tailplanes and be longitudinally unstable and achieve the same drag/lift ratios of an aircraft with canards and delta wings.
By the way the F-22 supasses the Eurofighter and Rafale in agility.
 
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latenlazy

Brigadier
The J-20 is around 2 meters longer than the F-22 without probe, the F-22 is almost 19 meters, the J-20 easily is 21 meters without probe and 23 meters with it
*Sigh* How many times do we have to dispel this. Every measurement done with a known objective reference indicates the J-20 is roughly 19-20 meters long.
 

siegecrossbow

General
Staff member
Super Moderator
*Sigh* How many times do we have to dispel this. Every measurement done with a known objective reference indicates the J-20 is roughly 19-20 meters long.

Correct. However we have to account for the fact that the total length of the F-22 include the length of the horizontal stabilizers that protrude a good length from the nozzles.
 

johnqh

Junior Member
Correct. However we have to account for the fact that the total length of the F-22 include the length of the horizontal stabilizers that protrude a good length from the nozzles.

Correct. However, F-22 has much bigger vertical stabilizers and its horizontal stabilizers are much bigger than J-20's canards.

There is really no point discussing this right now because none of us has any data. F-16E's empty weight is 25% heavier than F-16A, with same (or close to same) airframe. So all I can say is "who knows". It may be heavier than F-22, maybe lighter. We will have to wait to see.
 
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