Chengdu J-20 5th Generation Aircraft News & Discussions

[Asoka]

The J-20's wing span serves better supersonic maneuver, which was purposely decided by the designer. The loss of lift from the relatively small wings, when in subsonic and transonic regimes, is being offset by the lift from the vortex generated by the leading edge root extensions (LERX) behind the canards. One of the design key point of the LERX shape and position is direct the left and right vortex to meet and join together above the fuselage and hence create a low air pressure area to lift up the fuselage further.

Typhoon is well known for its good supersonic maneuver even though it's still inferior to F-22 in regards to supersonic performance. But, same with canard delta configuration, J-20 is even further optimized for supersonic maneuver while trying to maintain acceptable subsonic and transonic performance.

J-20 don't have a small wing. It's wingspan is about the same as F-22's. And swept back at about the same angle to maximize supersonic performance.

At 6.63m (vs J-20's 13.47m) , the F-104 has ridiculously small wingspan and wind surface area. It is noted for ridiculous fast acceleration and dangerous tendency that killed many new pilots.

"The Lockheed F-104 Starfighter is a single-engine, supersonic interceptor aircraft which later ...... Crew: 1; Length: 54 ft 8 in (16.66 m); Wingspan: 21 ft 9 in (6.63 m); Height: 13 ft 6 in (4.11 m); Wing area: 196.1 sq ft (18.22 m2); Airfoil: Biconvex ..."

 

[星海军事]

The world's largest integral titanium alloy frame.

 

[Asoka]

Both the J-20 and Eurofighter Typhoon are canard delta designs. Both are relatively modern designs.

However, one aircraft clearly has more wing area relative to the size of the fuselage.

Why did the J-20 designers put such tiny wings on the aircraft?

Would you design an aircraft like this? Why?

The enormous size difference between the Euro Typhoon and J-20.

• Crew: 1 (operational aircraft) or 2 (training aircraft)
• Length: 15.96 m (52.4 ft)
• Wingspan: 10.95 m (35.9 ft)
• Height: 5.28 m (17.3 ft)
• Wing area: 51.2 m²[388] (551 sq ft)
• Empty weight: 11,000 kg[389][N 6] (24,000 lb)
• Loaded weight: 16,000 kg[390][N 7] (35,270 lb)
• Max. takeoff weight: 23,500 kg[388] (51,800 lb)
• Fuel capacity: 5,000 kg (11,020 lb) internal[391][392]
• Powerplant: 2 × Eurojet EJ200 afterburning turbofan
  • Dry thrust: 60 kN (13,500 lbf) each
  • Thrust with af
• We know the length of J-20 from nose to tailboom is: 21.76, and nose to canted vertical tail tips is:22.3m, and wingspan is:13.47m

J-20 and Typhoon Nose to Nozzle Difference: 6.3m, which is more than that of difference between J-20 and F-22's 4.4m

 

[Figaro]

Another FYJS drawing of 2021 ... it appears to have the sawtooth nozzles.

http://www.fyjs.cn/thread-1882221-1-1.html

If there would be a 2D flat nozzle version for the J-20 in the near future, then it would definitely destroy the previous WS-15 theory.

Otherwise, nobody can easily tell which one is the WS-15, which one is not, unless the WS-15 got the 2D flat nozzle which can be easily distinguished.

If it has even 2D thrust vectoring on 2021, we shall see very soon when it performs aerial maneuvers. I'm of the kind that TVC isn't necessary but it would one bonus to the J-20's subsonic maneuverability if the latter does indeed incorporate it.

 

[cirr]

 

[ozranger]

Furthermore, supersonic maneuver combined with the J-20's large fuselage means MASSIVE ENERGY LOSS. Therefore, high thrust to weight ratio is desired, i.e. you need sufficient engines to make this design work.

Nope. J-20's fuselage is not bigger than other heavy fighters. Most people witnessing a real J-20 in Chengdu or Zhuhai said it's quite thin (I'd rather say it is relatively thin). While it is definitely not short, they described it as sort of "like a pencil".

Also J-20 is not a highly energy bleeding plane. All the J-20 performance we have seen so far showed that intervals between turns or climbs are pretty short without significant speed or altitude loss. Most of the time the climbs are rapid and steep as witnesses described the J-20 climbed like a rocket, which means that it maintains or regains energy even better than quite a lot of generation 4 fighters in low speeds. I for myself noticed that from quite a few YouTube videos that it was accelerating during the vertical climbs and showing it's gaining energy even when its climbing.

Don't mess it up with generation 4 fighter demos you usually see from the airshows. Most of them are doing eye catching tight turns with heavy energy loss that they normally end up with a long acceleration flight for regaining the energy. Those aircraft will not fly that way in real battles with stupid tight turns all around though.

The fighter demo which mostly impresses me with hints of heavy energy bleeding is the F-35 demo at Paris airshow. Every session of turns or rolls started after a required vertical climb. Yes it was able to climb vertically because the fuel it was carrying only half filled the tank or even less. But what's the point to have all its subsequent maneuvers only bleed energy until it is fully dried out without any sign of recovery? They seemed to put F-35 over there just to prove that it is a very sluggish plane when in normal flights with normal payloads.

Regarding super sonic performance, I don't know if J-20 can do supersonic cruise or not, but there is no problem on supersonic maneuver as its relatively large length/width ratio puts nearly all the fuselage behind the shock wave when flying supersonic. Supersonic performance optimization even applies to details such as the pointing direction of the actuator fairings under each wing.

 

[Figaro]

Nope. J-20's fuselage is not bigger than other heavy fighters. Most people witnessing a real J-20 in Chengdu or Zhuhai said it's quite thin (I'd rather say it is relatively thin), while it is definitely not short, and describe it as sort of "like a pencil".

Also J-20 is not a highly energy bleeding plane. All the J-20 performance we have seen so far showed that intervals between turns or climbs are pretty short without significant speed or altitude loss. Most of the time the climbs are rapid and steep as witnesses described the J-20 climbed like a rocket, which means that it maintains or regains energy even better than quite a lot of generation 4 fighters in low speeds. I for myself noticed that from quite a few YouTube videos I have seen, that it was accelerating during the vertical climbs, which meas it's gaining energy even when its climbing.

Don't mess it up with generation 4 fighter demos you usually see from the airshows. Most of them are doing eye catching tight turns with heavy energy loss that they normally end up with a long acceleration flight for regaining the energy. Those aircraft will not fly that way in real battles with stupid tight turns all around though.

The fighter demo which mostly impresses me with hints of heavy energy bleeding is the F-35 demo at Paris airshow. Every session of turns or rolls started after a required vertical climb. Yes it was able to climb vertically because the fuel it was carrying only half filled the tank or even less. But what's the point to have all its subsequent maneuvers only bleed energy until it is fully dried out without any sign of recovery? They seemed to put F-35 over there just to prove that it is a very sluggish plane when in normal flights with normal payloads.

Regarding super sonic performance, I don't know if J-20 can do supersonic cruise or not, but there is no problem on supersonic maneuver as its relatively large length/width ratio puts nearly all the fuselage behind the shock wave when flying supersonic. Supersonic performance optimization even applies to details such as the pointing direction of the actuator fairings under each the wing.

He doesn't know what he's talking about. That black dragon guy still insists that the J-20 is a giant plane with tiny wings ... 10 year old logic.

The J-20's wing span serves better supersonic maneuver, which was purposely decided by the designer. The loss of lift from the relatively small wings, when in subsonic and transonic regimes, is being offset by the lift from the vortex generated by the leading edge root extensions (LERX) behind the canards. One of the design key point of the LERX shape and position is direct the left and right vortex to meet and join together above the fuselage and hence create a low air pressure area to lift up the fuselage further.

Typhoon is well known for its good supersonic maneuver even though it's still inferior to F-22 in regards to supersonic performance. But, same with canard delta configuration, J-20 is even further optimized for supersonic maneuver while trying to maintain acceptable subsonic and transonic performance.

J-20 pilot says both it's supersonic and subsonic maneuverability are very good.

 

[aliaselin]

Really ??? It wasn't me !

But I just checked ... it is open.

It may have been set authority but not to every person.

 

[Figaro]

It may have been set authority but not to every person.

You're right, the engine thread is still closer for me. Weird.

 

[Deino]

You're right, the engine thread is still closer for me. Weird.

Strange ???? I see it open on my control-board.

Will check again.

 

[Figaro]

Strange ???? I see it open on my control-board.

Will check again.

"Not open for further replies"

 

[Deino]

Another FYJS drawing of 2021 ... it appears to have the sawtooth nozzles.

http://www.fyjs.cn/thread-1882221-1-1.html


If it has even 2D thrust vectoring on 2021, we shall see very soon when it performs aerial maneuvers. I'm of the kind that TVC isn't necessary but it would one bonus to the J-20's subsonic maneuverability if the latter does indeed incorporate it.

Ohhh come on guys ... CAC, You once had such a good photographer available always posting images taken even from within the fence. Just one clear image of 2021 at best from the rear side.

 

[Figaro]

Ohhh come on guys ... CAC, You once had such a good photographer available always posting images taken even from within the fence. Just one clear image of 2021 at best from the rear side.

This was drawn by a different witness ... all but confirming the WS-10X serrated nozzles even without a clear photo

 

[Deino]

This was drawn by a different witness ... all but confirming the WS-10X serrated nozzles even without a clear photo

Yes, but You know the usual suspects will again say: "Without a clear image or it never happened!"

 

[星海军事]

Another FYJS drawing of 2021 ... it appears to have the sawtooth nozzles.

http://www.fyjs.cn/thread-1882221-1-1.html


If it has even 2D thrust vectoring on 2021, we shall see very soon when it performs aerial maneuvers. I'm of the kind that TVC isn't necessary but it would one bonus to the J-20's subsonic maneuverability if the latter does indeed incorporate it.

That's true. Even WS-15 adopts axisymmetric TVC nozzle.