J-20 5th Gen Fighter Thread VI

[Engineer]

The J-20 then can be easily considered more of an interceptor interdictor fighter.

The Su-35 and Su-57 can also easily be considered interceptors, since the two have similar thrust-to-weight as J-20.

You have to consider the thrust it has now, not what it might have in 10 years.

The weight is not 15 tonnes as a poster suggested it will not make sense for the following reason, Su-27 will operate at 24 tonnes and its Al-31s will give it enough TWR to be in the 1:1.27 ratio, if the J-20 is so light then it will not need WS-15.

J-20 at least weight 29-30 tonnes at normal take off weight and a Max weight of 36 tonnes, thus to get a fighter type TWR it will need at least engines in the region of 15-17 tonnes like Su-57 and F-22.

WS-15 even you think the lowest thrust should be 15 tonnes and that will be a decent 1:1.1 TWR at normal take off

More or less like Su-57, thus it will explain you easily why they bought Su-35.


If in the future it has engines in the range of 15-17 tonnes it will become very likely a pure fighter, but as for now it has the numbers of an interceptor and an interdictor.

You have to consider what thrust Su-35 and Su-57 have now, not tens year in the future. Right now, the Su-35 and Su-57 have weaker thrust-to-weight ratio than F-22, so are in the same situation as J-20. The Su-35 and Su-57 are nevertheless classified as fighters, so J-20 is a fighter.

 

[b787]

No. The Flanker has a wing area of 62 m^2.

In case you didn't know, this is how you measure wing area mister plane expert.

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You're supposed to calculate the entire area between the wings. So much for all that "studying".

You supposed to know the equation includes wing span, oh! wing span guess what Flanker has longer wing span haha do you know why F-14 has more lift when its wings are less swept? bigger span, one thing is exposed area and another is reference area, do you know what is the reference area of a helo?

 

[b787]

The Su-35 and Su-57 can also easily be considered interceptors, since the two have similar thrust-to-weight as J-20.


You have to consider what thrust Su-35 and Su-57 have now, not tens year in the future. Right now, the Su-35 and Su-57 have weaker thrust-to-weight ratio than F-22, so are in the same situation as J-20. The Su-35 and Su-57 are nevertheless classified as fighters, so J-20 is a fighter.

my friend you lose your time there is a saying to a fool never answer if i am one do not answer me

 

[Inst]

Still surprised b787 isn't banned yet. He's not even an effective provocateur, he's just a troll.

That said, it's somewhat disappointing to realize the J-20 is limited in wing area (73m^2 vs 78m^2 on the comparably-sized F-22); it strongly suggests it will be closer to the interceptor side of the fighter-interceptor combo.

 

[ougoah]

There's just no method in dealing with this is there? It's like talking to a brick wall or playing chess with a pigeon, or arguing with an idiot. Whatever commonly used phrase. When you make a point, it is countered by a sentence that doesn't address what you have said. At first glance, it seems like a riddle designed to impress and inspire greater knowledge or wisdom, but after reading it several times, you realise the aim has been achieved. Your time was wasted.

 

[ougoah]

Still surprised b787 isn't banned yet. He's not even an effective provocateur, he's just a troll.

That said, it's somewhat disappointing to realize the J-20 is limited in wing area (73m^2 vs 78m^2 on the comparably-sized F-22); it strongly suggests it will be closer to the interceptor side of the fighter-interceptor combo.

Yeah it does have very small wings for its size. Said this before as well. But it could have something to do with lifting bodies and fuselage. Same reason why F-35 wings are small, Japanese concept has tiny wings. KFX concepts are drawn with small wings as well. Small wings do reflect less radar in bottom or top directions and all three have similar fuselage bodies. I think there is some speed and stealth benefits to smaller wings but i'm no aeronautical engineer. Just seeing patterns. B787 is probably paid to do these things. I find it hard to believe normal people can be so thick and yet intentionally annoying. Won't be a surprise to know heaps of people belonging to particular organisations read these forums along with others. Some may even be paid to say certain things. Only explanation. This guy's the craziest and most stubborn i've encountered my entire life. Something's amiss. No one is this ridiculous of a person.

 

[Engineer]

The answer is very easy if you know the distance the main wing has with the jet engine nozzles, on a fighter like Gripen, the main wing is farther form the nozzles, thus the supersonic center of lift moves much less aft and its wing its farther ahead of the main center of gravity, this tells you the J-20 needs to compensate that with big canards that increased drag, also in fighters like F-22 the TVC nozzles reduces drag at supersonic speeds, since the J-20 lacks them and the wing is pretty aft, the jet can not be so agile even at supersonic speeds add the aircraft has the main weapons bay ahead of the center of gravity, compared to a Typhoon the weapons are pretty ahead, the Typhoon for example has semi recessed weapons and these are farther aft, this releases a lot of pressure on the lift required fully loaded, it is not that the Chinese did not know that, but they were forced to designed like that due to stealth requirements and less advanced engine technology.
Add the type of inlet and you can see pretty much it flies in the region of Mach 1.2 to Mach 1.4 at supercruise with very good engines, as it stand now its cruising speed is subsonic, with high short burst of supersonic speed with afterburner.

The aircraft obviously is designed to achieve its max supersonic speed around Mach 1.8.

That is why the article does not rate so high the J-20 as our colleges do here

The J-20 configuration is a result of wind tunnel experiments that proven such configuration offers the largest lift-to-drag ratio, especially in high AoA flight regime. All this can be found in the designer of the configuration in his Journal Paper, in which he explicitly refers to requirements of jet-fighter and high-maneuverability and their application to J-20. The J-20, is no doubt a fighter, regardless of how much space there is between the wing and nozzles.

For those who haven't read the paper,

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An English translation kindly done by one of Sinodefence members

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[jobjed]

Still surprised b787 isn't banned yet. He's not even an effective provocateur, he's just a troll.

He has. His old username is mig29, which got banned. This is his new account which hasn't been banned because mods don't have banning powers anymore. The only one who can ban is webby who only shows up once a full moon.

That said, it's somewhat disappointing to realize the J-20 is limited in wing area (73m^2 vs 78m^2 on the comparably-sized F-22); it strongly suggests it will be closer to the interceptor side of the fighter-interceptor combo.

See my comment here.

 

[Engineer]

my friend you lose your time there is a saying to a fool never answer if i am one do not answer me

I wasn't answering you, but exposing the bullshit in your posts, thereby allowing others to benefit from true flight-dynamics knowledge.

 

[vesicles]

it has small wings great part of the lift is generated by the canards and a forward fuselage, it is designed to be relatively low drag because of the very large frontal cross section, it is not so bad in terms of drag, i think they wanted to reduce drag a lot specially since the widest part of the wing is at the end of the fuselage.

I do research and I mentor students and postdocs. If one of my postdocs tries to make any conclusion based on his/her "eyeballing" some of their images, I would tell them to stop talking and show me actual data! You have no right to say anything without any actual data to support you. By data, I mean actual numbers. It's difficult to come by, but that does not mean people can simply make random eyeballing conclusions. You shouldn't make any conclusions if there is no sufficient data.

All this "eyeballing" is equivalent to the claims made by those alien visitation theorists. They make conclusions based on what they "see" in the sky...