Featured Project Azm: Pakistan's Ambitious Quest to Develop 5th Generation Military Technologies.

[帅的一匹]

Single WS-15 design would makes sense for China, since it uses same engine as J-20, I kinda hope CAC design something like that.

That's what I always keep saying. A single engine design based on WS15 engine.

 

[enroger]

That's what I always keep saying. A single engine design based on WS15 engine.

I agree with you that a single WS-15 is a good option, but I was responding to his point about TWR, single WS-15 does not have more thrust then 2xWS-19.
As for PLA I'd agree single WS-15 makes a lot of sense in terms of cost and maintenance.

 

[帅的一匹]

I agree with you that a single WS-15 is a good option, but I was responding to his point about TWR, single WS-15 does not have more thrust then 2xWS-19.
As for PLA I'd agree single WS-15 makes a lot of sense in terms of cost and maintenance.

But a single engine AZM can have two side weapon bays.

 

[enroger]

But a single engine AZM can have two side weapon bays.

You mean like F-35 side bay? They don't necessarily offer more volume, may have more depth since they don't have to compete with air-intake for thickness.

My ideal design would be a single-engine delta canards with very thick wing-root/wing-blending section for internal bay and it also provides great lifting body profile. This combined with integrated structural design where the whole center frame + wing-root formed as single-piece with 3D printing.... man I'm jizzing all over myself, what bliss!

 

[Armchair]

When you say small wings, you mean small wing span or small wing chord? Those means very different things. For example changing to delta wings with same span but higher sweep angle will reduce wing-loading, however it will not produce more lift, merely reduce trans-sonic drag at the cost of shallower lift vs AoA curve.
However if you simply increase J-31 wingspan that will definitely increase lift, however at the cost super-cruise abilities. Therefore I've asked before whether super-cruise is needed for Paf.
As for TWR, I've said it before WS-19 has ample thrust. If you want even more TWR, you would be into twin ws-10/ws-15 territories.

I meant a very ballpark figure by smaller wings. Obviously so many factors come into play, including issues of what altitude and speed we are talking about. While the JSF / J-31 may produce body lift (which is another factor), my MK1 analysis is that the wings are generally smaller than they should be on an air superiority platform.

Wing lift is also relative to the drag produced. If you look at the Mirage series (3 or 2000), they are low drag designs, and their wings provide great capability for a high altitude, high speed profile, even with rather weak engines. Compare that to the J-31:
http://i.imgur.com/W1poDrS.jpg

Even in the latest videos, for a turn, they had to resort to afterburner. Showing that the plane, even with these wings, was still underpowered.

This becomes even more clear when you compare it to the general form of the F-22:
https://c7.alamy.com/comp/HDW871/a-...et-in-flight-showing-its-underside-HDW871.jpg

Or the Su-57:
https://thechive.files.wordpress.com/2017/08/russias-new-stealth-fighter-vs-the-f-22-raptor-215.jpg

For a design like that to work, you need TWR engines, that can overcome the large drag of a large wing. A large wing, which in turn gives the aerodynamic performance of a fighter specially for high altitude and high speed combat.

There is no real information on the WS-19. Or when it can be operational. What kind of performance it has. Its at this moment, a real pie in the sky. If and when it does show up, how much better will it be than the RD-93? We know that with Chinese assistance, the RD-93 now gives out over 105 kn of thrust.

If it is significantly superior and in the class of US turbofans, small wings and boxy air-frame or not, the J-31 will be worth the buy and perform competitively.

 

[enroger]

I meant a very ballpark figure by smaller wings. Obviously so many factors come into play, including issues of what altitude and speed we are talking about. While the JSF / J-31 may produce body lift (which is another factor), my MK1 analysis is that the wings are generally smaller than they should be on an air superiority platform.

Wing lift is also relative to the drag produced. If you look at the Mirage series (3 or 2000), they are low drag designs, and their wings provide great capability for a high altitude, high speed profile, even with rather weak engines. Compare that to the J-31:

For a design like that to work, you need TWR engines, that can overcome the large drag of a large wing. A large wing, which in turn gives the aerodynamic performance of a fighter specially for high altitude and high speed combat.

There is no real information on the WS-19. Or when it can be operational. What kind of performance it has. Its at this moment, a real pie in the sky. If and when it does show up, how much better will it be than the RD-93? We know that with Chinese assistance, the RD-93 now gives out over 105 kn of thrust.

If it is significantly superior and in the class of US turbofans, small wings and boxy air-frame or not, the J-31 will be worth the buy and perform competitively.

I see you keep coming back to mirage, as I've explained there're pros and cons with highly sweep back delta wings.
Pros: Low wing loading, low transonic drag, good for high speed high altitude.
Cons: Shallow lift vs AoA curve, that means to pull high-g they tend to need to pitch into high AoA, thus induce a lot more drag -> lose energy fast. Low sustained turn rate unless you have high TWR.

Those are what you get with delta-wings, this is the major difference in kinematics in M2k vs F-16, or J-31 vs J-20. No design is absolutely superior, it only depends on how you use them.

In terms of wing-span / length aspect ratio, J-31 is somewhere between F-22 and F-35, so it is not a marked difference by any stretch of imagination, I don't know how you get your feelings... As to the videos we have no idea what g and what air-speed J-31 is doing so I won't pay attention to it unless I have more info to go by.

If you want larger wings AND more powerful engine, you might as well go for twin engine heavy fighter, the likes of J-20, F-22 of Su-57....

Do you have source of Rd-93 getting 105kn? Anyhow WS-19 is slatted to have TWR over 9, max thrust over 11 tons wet, no idea on delivery date, however consensus is that it will come out around 2020 since it is the engine designed for J-31.

 

[Armchair]

I see you keep coming back to mirage, as I've explained there're pros and cons with highly sweep back delta wings.
Pros: Low wing loading, low transonic drag, good for high speed high altitude.
Cons: Shallow lift vs AoA curve, that means to pull high-g they tend to need to pitch into high AoA, thus induce a lot more drag -> lose energy fast. Low sustained turn rate unless you have high TWR.

Those are what you get with delta-wings, this is the major difference in kinematics in M2k vs F-16, or J-31 vs J-20. No design is absolutely superior, it only depends on how you use them.

In terms of wing-span / length aspect ratio, J-31 is somewhere between F-22 and F-35, so it is not a marked difference by any stretch of imagination, I don't know how you get your feelings... As to the videos we have no idea what g and what air-speed J-31 is doing so I won't pay attention to it unless I have more info to go by.

If you want larger wings AND more powerful engine, you might as well go for twin engine heavy fighter, the likes of J-20, F-22 of Su-57....

Do you have source of Rd-93 getting 105kn? Anyhow WS-19 is slatted to have TWR over 9, max thrust over 11 tons wet, no idea on delivery date, however consensus is that it will come out around 2020 since it is the engine designed for J-31.

Source for 105 kn is Messiach on this forum. Problem with Chinese engine deadlines is they have tended to not pan out as planned, given the history of the WS-10.

Look at the dry thrust of the F-35. Compare that to the dry thrust of two RD-93s. Compare the weights of the engines. You'll see that J-31 is not near the same league. And its trying to be "something between an F-22 and and F-35", which makes things considerably worse (F-22 wings are high drag, designed for high altitude and high speed fight, critical for BVR based combat).

There is really no comparison, China is just not there yet. Its all "yes in 2020 we will do so and so..."

A stealth fighter isn't just a fact sheet or an airframe (not that China has gotten there yet). Its about how the subsystems are integrated. The data fusion, the synergies developed. Its about the quality and reliability of the parts. Like:

"look mama, I have an J-31, but when I fire the missiles, they don't work". Chinese AAMs have not always been very reliable. PAF experience. See @Bilal Khan 777 's posts.

There is a limit to how much state enterprises can do. Ultimately, competition and the spirit of constant improvement has to be there. I am sure China will get there...

 

[Basel]

No need to get antsy

Cost of developing F35 approx $400 billion by US and projected order book in excess of 2000+ examples!!

For argument sake, AZM development costs $50 billion to Pak. Now thats a lot of money.

Pakistan will not reinvent wheel, so China assistance means that it will be made much quicker as China have already invested heavily in its Stealth projects and it will benefit Pakistan, also Turkey can be good help in the matter.

 

[Silicon0000]

Pakistan will not reinvent wheel, so China assistance means that it will be made much quicker as China have already invested heavily in its Stealth projects and it will benefit Pakistan, also Turkey can be good help in the matter.

Just curious to know what help turkey could do in AZM. TFX will be air superiority while AZM will be multirole. In avionics China will be ahead of Turkey by the time AZM fighter rollout if not it is already. May be compatibility with western platform is the only thing where they can help which will be good for export.

Pardon my poor english but i think you can understand what i wanted to know.

 

[Armchair]

Spool up times for AL-31s are very long. Thus not suitable for Pakistan, assuming WS-15 has similar spoolup times. In the short distance and thin geographical shape of Pakistan, you need something that can get in the air in a hurry.

 

[Basel]

Just curious to know what help turkey could do in AZM. TFX will be air superiority while AZM will be multirole. In avionics China will be ahead of Turkey by the time AZM fighter rollout if not it is already. May be compatibility with western platform is the only thing where they can help which will be good for export.

Pardon my poor english but i think you can understand what i wanted to know.

Do you even know what kind of support and resources are available to Turkey for their TFX project?? BAE will help them which is also part of another 5th gen project.

Spool up times for AL-31s are very long. Thus not suitable for Pakistan, assuming WS-15 has similar spoolup times. In the short distance and thin geographical shape of Pakistan, you need something that can get in the air in a hurry.

If Pakistan can afford EJ-200 updated version with TVC will be available for project AZM, which is quite capable engine, also it may be used in TFX of Turkey.

 

[enroger]

Source for 105 kn is Messiach on this forum.

Look, for an engine to increase max thrust fro 80kn to 105kn is quite a substantial claim, the least you can do is provide some valid link instead of pointing me to some id I don't know, it's called basic respect.

Now, to compare TWR of J-31, it has empty weight of 13.5 tons, assume 5 tons fuel + 1.5 tons weapon and 11 tons WS-19 will give it air combat TWR of 1.1. I'll just leave it at that.

F-22 wings are high drag, designed for high altitude and high speed fight, critical for BVR based combat

This sentence doesn't even makes sense, I don't know where to begin.....

A stealth fighter isn't just a fact sheet or an airframe

Now, of course stealth fighter is not just fact sheet as you call it, but then we weren't discussing subsystems are we? We started this discussion because you were making some statement about J-31 airframe. I don't know whether your little comment is meant to be condescending or it just came off this way....

"look mama, I have an J-31, but when I fire the missiles, they don't work"

If your previous comment weren't meant to be insulting, this one certainly is. Well done.

Now, I've tried to back up my arguments with facts and logic. I don't see any useful rebuttal from you except thinly veiled insult or your "feelings" about Chinese technology. I see you have already made up your mind on the matter, there is no need for further discussion. I bid you farewell.

 

[Silicon0000]

Do you even know what kind of support and resources are available to Turkey for their TFX project?? BAE will help them which is also part of another 5th gen project.



If Pakistan can afford EJ-200 updated version with TVC will be available for project AZM, which is quite capable engine, also it may be used in TFX of Turkey.

First i am not an expert thats why i asked things, not argue.
Secondly with BAE, doesn't it means lot of string attached?

 

[Army research]

The plane is a new locally designed with China's aid , dual engine plane. It's a clean sheet design.

 

[CriticalThought]

The plane is a new locally designed with China's aid , dual engine plane. It's a clean sheet design.

It makes perfect sense for it to be a clean sheet design, given that PAC has established a new Aviation Design Institute, it makes perfect sense.

The work we have already seen is taking the Chinese Wingloon design and making it more aerodynamically optimal. But this is preliminary work. Let's wait and watch for what the future holds