J-20 5th Gen Fighter Thread IV (Closed to posting)
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That theory was disproven when it was concluded that the feature that inspired it was a sensor and not a gap along the edge of the intake.These GIFs are from late 2011 and allegedly demonstrate J-20's intake design:
shen
Senior Member
the original J-20 was designed around WS-15s. extra engine power could've compensated for the tradeoffs of a fixed DSI intake. if the rumor of push for early entry into service with AL-31 is true, the mesh hexes could be some form of variable intake to compensate for the weaker engines.
On both the J-10 and J-20, I noticed that even on short take-offs and landings, the canards do not deflect a lot even for steep climbs.
I actually doubt I have seen them deflect more than 10 degrees on take-offs or landings.
This struck me as I watched the latest videos of 2011 first flight. And recalling the various videos of previous J-20 and J-10 flights.
The greatest deflections occurred when the pilot was testing the flight controls and when using the canards as air brakes to slow the ground roll.
If for low-speed flight, when aerodynamic forces are much, much smaller, the deflection angles remain modest, then how much LESS deflection might be needed in high-speed flight.
Perhaps past experience with the J-10's canards led CAC to once again choose this configuration as they would not be moving (deflecting) much during high-speed encounters with other aircraft, helping to preserve the J-20's stealthiness.
The need for movement and correction would be even less if the canards were not just control but also lifting surfaces, adding to the overall lift of the aircraft.
And the dihedral angle of the canards might not just be for reducing interference with the main wing and its control surfaces (leading edge slat, aileron and flaps) but also to improve the aircraft's stability at higher speeds.
Just musing here.
I actually doubt I have seen them deflect more than 10 degrees on take-offs or landings.
This struck me as I watched the latest videos of 2011 first flight. And recalling the various videos of previous J-20 and J-10 flights.
The greatest deflections occurred when the pilot was testing the flight controls and when using the canards as air brakes to slow the ground roll.
If for low-speed flight, when aerodynamic forces are much, much smaller, the deflection angles remain modest, then how much LESS deflection might be needed in high-speed flight.
Perhaps past experience with the J-10's canards led CAC to once again choose this configuration as they would not be moving (deflecting) much during high-speed encounters with other aircraft, helping to preserve the J-20's stealthiness.
The need for movement and correction would be even less if the canards were not just control but also lifting surfaces, adding to the overall lift of the aircraft.
And the dihedral angle of the canards might not just be for reducing interference with the main wing and its control surfaces (leading edge slat, aileron and flaps) but also to improve the aircraft's stability at higher speeds.
Just musing here.
manqiangrexue
Brigadier
Hi, I'm new here but have been reading and following this thread and the development of China's military aviation since 2007. I usually like to just sit here and watch but a nagging question has lead me to join so I could ask.
It seems that there is a general consensus here that J-20 2011 uses an AL-31 variant to power it. I would like to ask how this conclusion was arrived at. To me, the engine petals (as seen here ) look like nothing in service from any country, and assuming that Russia would probably not send a prototype to China, the logical conclusion to me, is that they are a variant of WS-10. This is supported by the fact that WS-10A is in service on the J-11B. I understand that there is the possibility that an AL-31 is inside, with the petals changed, but, this seems unlikely to me for 2 reasons. The first reason is that there seems nothing special about those petals; they aren't stealthy, and they aren't thrust-vectored so why bother changing them from the AL-31 petals? The second reason is that there are pictures of a J-20 with 1 AL-31 and 1 unidentified engine (as seen here, in this photo in which everything else was photoshopped ). If they didn't bother to change the petals of the AL-31 here, why would they do that when using 2 engines? So to me, the logical conclusion here is that the engines inside are probably some WS-10X variant but it seems that for other reasons, people think it is AL-31.
So... other than saying that you simply cannot take another heart-break from the Chinese engine industry (xiabonan), why would you assume they are an AL-31 variant and not a WS-10 variant?
It seems that there is a general consensus here that J-20 2011 uses an AL-31 variant to power it. I would like to ask how this conclusion was arrived at. To me, the engine petals (as seen here ) look like nothing in service from any country, and assuming that Russia would probably not send a prototype to China, the logical conclusion to me, is that they are a variant of WS-10. This is supported by the fact that WS-10A is in service on the J-11B. I understand that there is the possibility that an AL-31 is inside, with the petals changed, but, this seems unlikely to me for 2 reasons. The first reason is that there seems nothing special about those petals; they aren't stealthy, and they aren't thrust-vectored so why bother changing them from the AL-31 petals? The second reason is that there are pictures of a J-20 with 1 AL-31 and 1 unidentified engine (as seen here, in this photo in which everything else was photoshopped ). If they didn't bother to change the petals of the AL-31 here, why would they do that when using 2 engines? So to me, the logical conclusion here is that the engines inside are probably some WS-10X variant but it seems that for other reasons, people think it is AL-31.
So... other than saying that you simply cannot take another heart-break from the Chinese engine industry (xiabonan), why would you assume they are an AL-31 variant and not a WS-10 variant?
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Welcome aboard, manqiangrexue.
Thanks for the well thought out and reasoned question.
We'll see how forum members respond.
lcloo
Captain
That is a good point. Similar mesh also appeared on intake of JF-17, although they are not hexagonal shape. I suspect they could be serving the same function.
the matter of J-20's engine was settled a long time ago when the picture of 2001's afterburner flameholder matches AL-31 flameholder
whether 2011 uses the same Al-31 engine or not remains to be seen, but we can assume it's still AL-31 as no changes made to the engine nozzle petals, and it's still the same blue afterburner flame
whether 2011 uses the same Al-31 engine or not remains to be seen, but we can assume it's still AL-31 as no changes made to the engine nozzle petals, and it's still the same blue afterburner flame
Hi and wellcome on bord !
To admit Your question regarding the new silverish pedals has been discussed here already so often and I try to summarise what we concluded (or at least me !)
First there is a number of certain items which are substantially different between an AL-31FN and a WS-10A, these are the number of pedals, the inner structure of the flame holder ring, the external - sorry, difficult to say for me - composition of the engine's exhaust like how long is it, how many seperate visible rings /items are visible between airframe and final end of the engine and even more the distance between them.
Overall - I hope You got what I meant - the items found on the J-20's exhaust are identical to an AL-31F ... only the colour is wrong and even here we have images showing the silver to peel off and even a J-20 with one silver exhaust and one standard exhaust. As such - and please don't ask me why - these engines are simply a version of the AL-31FN with a silver coat.
Deino
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