J-XY/J-35 carrier-borne fighter thread

[taxiya]

The paper is really just a proof of concept.

And yeah, hence my guess that the J-35 would be around 14.5 tonnes.

The paper is actually report from design and manufacturing method of FC-31. So it is a realization rather than proof of concept. Two examples in the paper are actually seen by public:

1. One piece wing-body structure that reduces 38% mass compared to conventional construction. We have seen FC-31's wing-body being paraded through China.
2. The horizontal stablizer design in version 2 reduces 17% mass compared to version 1.

In reference, similar sized aircraft F-18 is above 10t empty, F-35A is above 13t empty, both of them are made in a more conventional method. FC-31's 12.5t or 14.5t are more or less around F-35A but with a radically improved manufacturing process that is proven to reduce mass by anything from 10% to 38%. Why is that "too good to be true" or hard to believe?

 

[Alfa_Particle]

Why is that "too good to be true" or hard to believe?

I mean, an empty t/w of 1.5 or even higher. Who wouldn't drool at that? I'm just being slightly pessimistic.

Considering it's huge wingspan and thrust, it probably has pretty mental low and high speed performance potential.

Aside from dogfighting and supercruise capabilities which are basically given, it can 'throw' missiles faster, execute evasive maneuvers easily, and have impressive payload capabilities.

It's quite literally the dream 5th Gen.

F-22 @ 19t empty weight and 31,8 tons of thrust comes in at 1.67 twr...


What does the Su-57 engine got to do with this? And why start with a higher number than the lower? It's confusing.

19 tonnes is the (as far as I'm aware) unofficial lowest figure. I've heard some say 20+.

But even so, if we take a reasonably optimistic figure for the J-35, 14 tonnes and 235.36 kN, it'd be 1.714 TWR. Still above by a somewhat considerable margin.

I was originally talking to someone else about this, and the rumour of the AL-51 having 245 kN thrust was mentioned before this. I didn't remove this part when I pasted here.

Why is it confusing? I start with the safer figures to the more iffy ones.

 

[Temstar]

I mean, an empty t/w of 1.5 or even higher. Who wouldn't drool at that? I'm just being slightly pessimistic.

Considering it's huge wingspan and thrust, it probably has pretty mental low and high speed performance potential.

Aside from dogfighting and supercruise capabilities which are basically given, it can 'throw' missiles faster, execute evasive maneuvers easily, and have impressive payload capabilities.

It's quite literally the dream 5th Gen.


19 tonnes is the (as far as I'm aware) unofficial lowest figure. I've heard some say 20+.

But even so, if we take a reasonably optimistic figure for the J-35, 14 tonnes and 235.36 kN, it'd be 1.714 TWR. Still above by a somewhat considerable margin.

I was originally talking to someone else about this, and the rumour of the AL-51 having 245 kN thrust was mentioned before this. I didn't remove this part when I pasted here.

Why is it confusing? I start with the safer figures to the more iffy ones.

Empty TWR of 1.5 is a lot, by my calculation Super Hornet's empty TWR is 1.37, F-35C is 1.24.

I imagine higher TWR would help it take off from Liaoning and Shandong, so compared to CATOBAR-only fighters high thrust may be particularly selected for in the design if STOBAR take-off is important.

 

[Alfa_Particle]

Empty TWR of 1.5 is a lot, by my calculation Super Hornet's empty TWR is 1.37, F-35C is 1.24.

I imagine higher TWR would help it take off from Liaoning and Shandong, so compared to CATOBAR-only fighters high thrust may be particularly selected for in the design if STOBAR take-off is important.

Definitely. It's ridiculous already, but to think they have the potential to hit 1.7+, STOBAR takeoff should be a walk in the park.

Assuming these figures of the J-35 are accurate, we're looking at potentially the most capable carrier fighter here.

 

[ACuriousPLAFan]

Empty TWR of 1.5 is a lot, by my calculation Super Hornet's empty TWR is 1.37, F-35C is 1.24.

I imagine higher TWR would help it take off from Liaoning and Shandong, so compared to CATOBAR-only fighters high thrust may be particularly selected for in the design if STOBAR take-off is important.

Just a side question: What are the empty TWRs of the J-20 (with WS-10C) and J-20A (with WS-15), for comparison?

 

[Engineer]

I've came across some figures regarding the J-35 and quite frankly, I don't know if I should take them seriously.

Apparently, with the research of Wang Xiangming, they managed to control the empty weight of the J-35 to a ridiculously light figure. There are images floating around of the new, revised structural design in a paper. Called 《飞机新概念结构设计与工程应用》, which translates to "New concept of aircraft structural design and engineering applications".

The figures floating around ranges from 16-14 tonnes (which is already quite unbelievable), and a few claiming 12.5 tonnes (AL-51 having 200+ kN thrust level delusion imo, but we'll see).

The figure I heard the most is 14.5 tonnes. With WS-19 rumored with having around 112.5 kN of thrust each and a pair's combined weight being *less* than a F135, that makes approx. 225 kN per aircraft.

That means a whooping thrust to weight ratio (empty) of 1.582. Taking fuel, payload, even 2D TVC into consideration, it'd still be around 1.3 to even 1.5. The J-35 would have the highest t/w figure in terms of fighter aircraft, in the entire world, right now.

I'm taking this figure with an entire salt mine. Even if I increased the empty weight to 17 tonnes and a combined thrust of 210 kN, the t/w would still be 1.26.

Onto the most ridiculous rumor, 12.5 tonnes empty and 235 kN combined, the t/w would be 1.9. Which, quite frankly, have an *extremely slim* probability to straight-up impossible.

My *very* optimistic guess would be 1.45. The realistic, safe figure would probably be 1.3, or even lower. But still, in an optimistic scenario of the J-35 having 2D TVC, it has the potential of being the most versatile (and perhaps even agile) and stealthiest 5th generation fighter. Hence I'm quite doubtful of these figures. Take em with a whole mine of salt.

Does anyone know any solid info about the J-35's weight?

Here's some pictures from the said paper:
View attachment 124839

Nothing unrealistic about the figures. Look up the F-15 variant called Streak Eagle and the Su-27 variant P-42, airframes that are stripped down to the bare necessities for beating world records. Streak Eagle had a TWR of 1.4. P-42 had a TWR of 2. Obviously, you should expect production models to be a lot more heaiver.

 

[Alfa_Particle]

Nothing unrealistic about the figures. Look up the F-15 variant called Streak Eagle and the Su-27 variant P-42, airframes that are stripped down to the bare necessities for beating world records. Streak Eagle had a TWR of 1.4. P-42 had a TWR of 2. Obviously, you should expect production models to be a lot more heavier.

I didn't say it's unrealistic though. I'm just a bit taken aback. The examples you mentioned are all non-production 4th Gens, no surprise they have a ridiculous TWR.

But a production carrier 5th Gen with those numbers? Anyone would do a double take.

 

[Michaelsinodef]

I didn't say it's unrealistic though. I'm just a bit taken aback. The examples you mentioned are all non-production 4th Gens, no surprise they have a ridiculous TWR.

But a production carrier 5th Gen with those numbers? Anyone would do a double take.

Newer materials, production methods, design etc.

Like, older 4th gen fighters (and even a lot of newer 4.5th gen upgrades and the likes) use older methods for airframe production and the likes from like ~80s, 90s and 00s.

Versus newer 5th gen with late 00s and 10s tech and upgrades (especially stuff like carbon fiber).

Shouldn't be that surprising that weight savings of some 10-30% happens.

 

[Michaelsinodef]

Newer materials, production methods, design etc.

Like, older 4th gen fighters (and even a lot of newer 4.5th gen upgrades and the likes) use older methods for airframe production and the likes from like ~80s, 90s and 00s.

Versus newer 5th gen with late 00s and 10s tech and upgrades (especially stuff like carbon fiber).

Shouldn't be that surprising that weight savings of some 10-30% happens.

Oh yea, this is also something that's gonna be very hard for other nations to catch up with as well.

Such as Turkiye's '5th gen' or Korea's 4.5++ (KFX or KF-21 I think it was), which from videos and pictures, seems like they are more akin to 4th gen (F16, which is a plane that they have license build).

 

[Alfa_Particle]

Just a side question: What are the empty TWRs of the J-20 (with WS-10C) and J-20A (with WS-15), for comparison?

Can't remember any solid figures of the top of my head, so feel free to correct any of my figures used.

For the J-20, assuming an empty weight of 19 tonnes, with WS-10C having a thrust of 150kN each, the TWR would be 1.61.

The J-20A has to be somewhat heavier with the hump and WS-15, so I'll assume 21 tonnes. WS-15 has 181kN each so that makes a TWR of 1.758.