J-20 5th Gen Fighter Thread IV (Closed to posting)

[latenlazy]

What the J-20 would look like with clipped wing and control surface corners. I suspect though that the canards won't actually have clipped corners, as that may affect the vortices generated at the canard wing tips.

View attachment 8576

 

[andyhugfan]

I this can be believed, the decision to choose Chengdu's design over Shenyang's more conventional layout for China's fifth generation fighter was made around end of october, 2007.

While the first leaked flight of Chengdu's prototype J-20 was made in January 2011.

Does this mean that Shenyang had a 5th gen. prototype ready by 2007?

 

[Air Force Brat]

What the J-20 would look like with clipped wing and control surface corners. I suspect though that the canards won't actually have clipped corners, as that may affect the vortices generated at the canard wing tips.

View attachment 8576

While clipping the verts would decrease RCS, the J-20 likely wouldn't suffer from that aerodynamically, as the ventral fins give it plenty of yaw stability, clipping the main wing and the canards will reduce lift, not a good thing, particulary when you don't have all the thrust you were hoping for. So if you reduce the area of the canards, you will have to increase the deflection to achieve the same rate of pitch transition, also you reduce the effective wing area of the whole aircraft and thus its total lift, not going to happen, but it looks "snarky"! brat

 

[Air Force Brat]

Does this mean that Shenyang had a 5th gen. prototype ready by 2007?

No, but they had proof of concept engineering data and likely drawings to illustrate that, also the J-20s first flight, was its first flight , a ballsy move to impress not only the sec-def, but your neighbors and other skeptics, I keep wondering where people get the idea that the Chinese people are so "cautious"??????? brat

 

[vesicles]

I keep wondering where people get the idea that the Chinese people are so "cautious"??????? brat

Because they are. Not only that, but it's human nature to be cautious on important stuff on this. Would you try a new dish for the first time on an important occasion, like a Thanksgiving dinner? I know someone does, but most people would have tested their recipes ahead of time... And it would be a smart thing to do. We went to a cousin's house for Thanksgiving dinner one year and he decided to try deep-frying his turkey for the first time on the big day. And he almost burned down the house...

And the Chinese govn't has been very cautious in terms of displaying their high tech stuff in public. That is a fact. And historically, Chinese have been known to be fully prepared for important things. They don't simply "jump into it". And I know most govn't in the world are like that.

 

[latenlazy]

While clipping the verts would decrease RCS, the J-20 likely wouldn't suffer from that aerodynamically, as the ventral fins give it plenty of yaw stability, clipping the main wing and the canards will reduce lift, not a good thing, particulary when you don't have all the thrust you were hoping for. So if you reduce the area of the canards, you will have to increase the deflection to achieve the same rate of pitch transition, also you reduce the effective wing area of the whole aircraft and thus its total lift, not going to happen, but it looks "snarky"! brat

The production version of the F-22 had clipped wing corners. I'd imagine the aerodynamic penalties were small enough for that to not matter, so it's really a matter of degrees. That said, the drawing was a hypothetical. We'll see what the rest of the plane looks like, if there are further changes to the production model.

 

[no_name]

Does this mean that Shenyang had a 5th gen. prototype ready by 2007?

I don't think a full scale prototype was built until the design is selected. Of coure they would have stuff like wind tunnel data, models of the plane and exhibition of aircraft subsystems.



-601 sent 15 reports and 14 presentation script on 18 august.

-on august 23rd 601 did a whole day report to experts in beijing, including
videos, the overview report and 13 other reports.

-611 did their reports on 24th august

On 29th august experts went to Shenyang, visited laboratories on 30th, displays on the design, listened to their reports. They compared canard and conventional designs as well as caret and dsi designs.

 

[Quickie]

The J-20 has a smaller wing area (relatively to the aircraft itself). Clipping a part of its wing has a greater effect on aerodynamics lift than would be the case with the F-22.

No need to sweat over it though. We'll know when more pictures start to come in.

 

[latenlazy]

The J-20 has a smaller wing area (relatively to the aircraft itself). Clipping a part of its wing has a greater effect on aerodynamics lift than would be the case with the F-22.

No need to sweat over it though. We'll know when more pictures start to come in.

Haha, I drew the picture for fun. Didn't think it'd stir a serious conversation XP.

 

[Air Force Brat]

Haha, I drew the picture for fun. Didn't think it'd stir a serious conversation XP.

Well, and I'm very happy that you did, waiting on a picture, or someone to re-post an old picture is maddening, especially as I noted the first flight with the US Sec Def in country was a brilliant PR move, but also a statement of Chinese "competency". For whatever reason the new team has put a lid on what was arguably one of the most interesting aircraft roll-outs of this Century, and a brilliant leg up in Chinese posterity in the known world. There are lots of news threads on the internet, this is the only place where one can get the engineering/application/aerodynamic perspective that make the Sino Defense forum "worth the time", such as Jeff Heads thread on the Zumwalt, I have learned a great deal. Same here with the J-20, it truly is a "new generation" fighter, in many more ways than one, and its departure from the "status quo" aerodynamically and structurally, have been well illustrated by the Eng and you fellows who have waited so patiently for this very important airplane.

Like Deino's article on the J-15, there is something here for every-body, and in-put from many different perspectives and disciplines, these things give the "Sino-Defense" forum depth, so keep drawing those little sketches, the passionate involvement of our members may occasionally result in "discussions" and "diversions", but provide what is likely one of the few true "forum" type discussions on the web. NOW Where is 2003?????? good grief, the least they could do is let us in on the secret????

Lots of brilliant aircraft ideas have been "doodles on a napkin or legal pad to while away the hours that the world is trying to bore us to death! keep posting. brat