2nd Pak FA prototype maiden flight pics

[Project 627]

He is trolling but you should repudiate with facts.

The J 20 uses serpentine intakes and F 35 style LOAN engines, so yes its quite stealthy.

J-20 engines have some stealth features, but saying it is quite stealthy is over the top. You can only say that for the F-22 and B-2 engines.

As for those J-20 fanboys, you keep bashing the PAK FA, just don't be shocked one day as you find out how advanced PAK FA really is.

 

[tanlixiang28776]

J-20 engines have some stealth features, but saying it is quite stealthy is over the top. You can only say that for the F-22 and B-2 engines.

As for those J-20 fanboys, you keep bashing the PAK FA, just don't be shocked one day as you find out how advanced the PAK FA really is.

F 22 , F 35, and J 20 all use methods to lower the IR signature of the Engine exhaust and radar reflectivity.

For Radar stealth all three use serpentine intakes with the F 35 and J 20 also using DSI so in radar stealth they are approximately equal.

For IR stealth they also use similar methods.

The F22 uses a rectangular ceramic lined exhaust to the detriment of power as round ones are more efficient. The F 35 use round exhausts with LOAN jagged and ceramic lined exhausts. There is not a enormous difference in the core of the methods.

The J 20 follows the F 35 method.

Personally I am just disappointed the Russians did not do a better job. Such visible problems should not be ignored simply because you want to. I hope they can fix it soon.

 

[Project 627]

F 22 , F 35, and J 20 all use methods to lower the IR signature of the Engine exhaust. They also all use serpentine intakes.

The F22 uses a rectangular exhaust to the detriment of power as round ones are more efficient. The F 35 use round exhausts with LOAN jagged and ceramic lined exhausts.

The J 20 follows the F 35 method. There is not enough difference to warrant such a large classification change.

Personally I am just disappointed the Russians did not do a better job. Such visible problems should not be ignored simply because you want to.

We will see how disappointed you still are when the third prototype rolls out.

 

[tanlixiang28776]

We will see how disappointed you still are when the third prototype rolls out.

I honestly thought they would fix most of it on the second prototype. That is not the case. If the third prototype comes out and they don't fix it then I will be truly disappointed.

 

[Project 627]

I honestly thought they would fix most of it on the second prototype. That is not the case. If the third prototype comes out and they don't fix it then I will be truly disappointed.

The first two prototypes were for aerodynamic testing only, and pretty much the whole damn world knew that the second prototype would be nearly identical to the first.

 

[tanlixiang28776]

The first two prototypes were for aerodynamic testing only, and pretty much the whole damn world knew that the second prototype would be nearly identical to the first.

Well let them surprise me next time then. I can only judge what I See. I'm not a freaking seer.

 

[Roybot]

Well let them surprise me next time then. I can only judge what I See. I'm not a freaking seer.

I read somewhere, that there wont any major visible change until the 4th prototype.

 

[Project 627]

I read somewhere, that there wont any major visible change until the 4th prototype.

YES and NO

We will see some changes on the third prototype, but in my opinion the major changes will be in the pre-production prototype.

 

[angeldemon_007]

F 22 , F 35, and J 20 all use methods to lower the IR signature of the Engine exhaust and radar reflectivity.

For Radar stealth all three use serpentine intakes with the F 35 and J 20 also using DSI so in radar stealth they are approximately equal.

For IR stealth they also use similar methods.

The F22 uses a rectangular ceramic lined exhaust to the detriment of power as round ones are more efficient. The F 35 use round exhausts with LOAN jagged and ceramic lined exhausts. There is not a enormous difference in the core of the methods.

The J 20 follows the F 35 method.

Personally I am just disappointed the Russians did not do a better job. Such visible problems should not be ignored simply because you want to. I hope they can fix it soon.

Any official reports are on these claims or you got all these from some of the blurred images taken from 500 m away ???

 

[gambit]

For Radar stealth all three use serpentine intakes with the F 35 and J 20 also using DSI so in radar stealth they are approximately equal.

Diverterless Supersonic Inlet was never for radar reflectivity but for inlet air control. Its effect on radar reflectivity, if any, is incidental, not deliberate. If anything, for the J-20's DSI there are no credible data to say that the DSI have any reduction in engine radar reflectivity. I see you got suckered.

For IR stealth they also use similar methods.

The F22 uses a rectangular ceramic lined exhaust to the detriment of power as round ones are more efficient. The F 35 use round exhausts with LOAN jagged and ceramic lined exhausts. There is not a enormous difference in the core of the methods.

A non-circular exhaust will produce a greater surface area for cooling than a circular exhaust one.

 

[tanlixiang28776]

Any official reports are on these claims or you got all these from some of the blurred images taken from 500 m away ???

First of all images are quite clear as well as videos. They are very prominent and visible.

Try contributing something next time.

If you want official you should avoid discussing Chinese military matters.

 

[tanlixiang28776]

Diverterless Supersonic Inlet was never for radar reflectivity but for inlet air control. Its effect on radar reflectivity, if any, is incidental, not deliberate. If anything, for the J-20's DSI there are no credible data to say that the DSI have any reduction in engine radar reflectivity. I see you got suckered.

I said they were approximately equal. I never said the DSI was superior here. Do you need to insult posters that don't agree with you every time?

A non-circular exhaust will produce a greater surface area for cooling than a circular exhaust one.

Depends on how long the exhaust is as well. Have any figures for the F 22 vs F 35 exhausts? If there is a difference it wouldn't be large. Newer ceramics would also be more efficient I presume.

 

[gambit]

I said they were approximately equal. I never said the DSI was superior here.

And that remain a baseless claim.

Depends on how long the exhaust is as well. Have any figures?

A Chinese claim about the J-20 among the many that has no supporting evidences and yet demand supporting evidences of others...

But here is a teaser on engine exhaust design...

Note the last sentence. The USAF is not going to release comparative data on engine IR emission levels, suffice to say that engine exhaust shapes and patterns are exhaustively researched and their effects on IR emissions are well documented.

 

[tanlixiang28776]

And that remain a baseless claim.

How so? Very similar designs have extraordinarily different results?

A Chinese claim about the J-20 among the many that has no supporting evidences and yet demand supporting evidences of others...

But here is a teaser on engine exhaust design...

Note the last sentence. The USAF is not going to release comparative data on engine IR emission levels, suffice to say that engine exhaust shapes and patterns are exhaustively researched and their effects on IR emissions are well documented.

Do you have to be an a** every time you respond. You know perfectly well the Chinese military does not release data on these things and neither does the US for that matter.We don't even know the exact ballistic performance of the 5.8mm and you want data on stealth engine exhausts?

As for the rectangular vs round exhausts it certainly can be compensated by longer exhausts or more effective ceramics along with LOAN design like in the F 35 and J 20.

 

[gambit]

How so? Very similar designs have extraordinarily different results?

It remains baseless and there is a play on words here. In order to have a reasonable comparison, we need a 'base' and a 'comp'. It does not matter if A is 'base' or 'comp'. But as long as one is missing, you cannot make statements even to the effect of 'approximately'.

Do you have to be an a** every time you respond.

No...Not every time.

You know perfectly well the Chinese military does not release data on these things. We don't even know the exact ballistic performance of the 5.8mm and you want data on stealth engine exhausts?

Then do not make statements like 'approximately equal' for anything.

As for the rectangular vs round exhausts it certainly can be compensated by longer exhausts or more effective ceramics along with LOAN design like in the F 35 and J 20.

The issue here is not so much the exhaust stream length but the core temperature of the exhaust itself. A rectangular shape will have a lower core temperature overall.