The T-50 (PAK-FA) Thread

[Pilotasso]

Right. Supersonic aircraf ducts cant be convergent at the intakes. The plane would never go supersonic that way.

[Bucic]

Right. Supersonic aircraf ducts cant be convergent at the intakes. The plane would never go supersonic that way.

Engines are not my major but I dare to say with such ducts engines would barely run.

[Pilotasso]

Can someone translate what the engineer is explaining at 1:54? (pelican tail?)

 

[Griffin]

Yeah, he's explaining that the whole vertical fin is moving.

 

By the way, what would be the correct term for fully moving vertical fin?

 

As fully moving horizontal surface is stabilator, then this is...?

[Bucic]

"all-flying tail surfaces" so it would by all-flying rudder surface maybe.

http://oea.larc.nasa.gov/PAIS/Supersonic.html

 

Edit:

Right. Supersonic aircraf ducts cant be convergent at the intakes. The plane would never go supersonic that way.

I think they can and maybe even they should ;)

 

http://www.concordesst.com/powerplant.html

Edited January 31, 2010 by Bucic

[Pilotasso]

"all-flying tail surfaces" so it would by all-flying rudder surface maybe.

http://oea.larc.nasa.gov/PAIS/Supersonic.html

 

Edit:

 

I think they can and maybe even they should ;)

 

http://www.concordesst.com/powerplant.html

 

Nope, thats not a convergent duct. It has a shockwave ramp wich then lead into a divergent duct. Its different ;)

 

That happens because at subsonic speeds, convergent ducts lead to acceleration of the air, but at supersonic speeds its the opposite, it becomes clogged with trapped air.

 

So the trick is to create a shockwave precisely in 1 spot (only at the ramp, nowhere else) so the remaining flow downards the duct is subsonic, but with higher density. Then it is further reduced as it travels torwards the engine (the divergent part of the duct), the engine further reduces air speed as it proceeds through the compressor.

 

So in short, the rule of thumb is to deccelerate air ever before its fed to the engine. Gases only accelerate aft of the combustion chamber.

 

This brings numerous advantages: Air is slower, so less engine RPM's, and you avoid a fuel flamout. Its denser so it gives more thrust, and you get to avoid supersonic flow and shockwaves inside the engine wich, believe me would be very very very BAD :)

 

EDIT: typos

Edited January 31, 2010 by Pilotasso

[Bucic]

Nope, thats not a convergent duct. It has a shockwave ramp wich then lead into a divergent duct. Its different ;)

 

That happens because at subsonic speeds, convergent ducts leads to acceleration of the air, but at supersonic speeds its the opossite, it becomes clogged with trapped air.

 

So the trick is to create a shockwave precisely in 1 spot (only at the ramp, nowhere else) so the remaining flow dowards the duck is subsonic, but with higher density. Then it is further reduced as it travels torwards the engine (the divergent part of the duct), the engine further reduces air speed of the air as it proceeds through the compressor.

 

So in short, the rule of thumb is to deccelerate air ever before its fed to the engine. Gases only accelerate aft of the combustion chamber.

 

This brings numerous advantages: Air is slower, so less engine RPM's. Its denser so it gives more thrust, and you get to avoid supersonic flow and shockwaves inside the engine wich, believe me would be very very very BAD :)

Oh :)

[Griffin]

"all-flying tail surfaces" so it would by all-flying rudder surface maybe.

I was hoping to see something like "rudderator" or "yawfins". :D

[Boneski]

Video

 

For the guys looking for more info Not sure if this was posted... maybe its old news...?

 

http://news.bbc.co.uk/2/hi/europe/8486812.stm

 

http://www.timesonline.co.uk/tol/news/world/europe/article7007913.ece

 

Edited January 31, 2010 by Boneski

[Griffin]

I don't want to take part (or start it) on the debate about which one is better. Just came across this on mp.net and it's just another way to look at their features:

 

 

http://www.ausairpower.net/APA-NOTAM-081109-1.html

Edited January 31, 2010 by Griffin

[Pilotasso]

the board is VERY WRONG on many accounts. nuff said

[GGTharos]

Wow, I guess Peter Goon needs to find a new job, 'cause analysis isn't something he's good at.

 

I mean, to start with - who said the F-35 cannot accomplish supersonic weapon delivery?

Secondly, how come the F-35's EXTREME SA capability not get a +1?

And what's up with the TWR thing? The F-35's engine is pretty tuned up.

And how it is that the T-50 has 'extreme agility' compared to a raptor?

 

He's one of Kopp's friends, isn't he? Aka clue-free.

[Pilotasso]

JSF cant fly above 45000 feet buhahahaha

[Griffin]

Seems the debate on F-35 in Australia is so hot that some are even ready to claim a Russian plane superior to oppose JSF. :D

[GGTharos]

It isn't hot at all. The RAAF isn't listening to him, and I'd say they know better. Basically as far as RAAF is concerned, there's no debate, and Kopp is clue-free. ;)

 

Seems the debate on F-35 in Australia is so hot that some are even ready to claim a Russian plane superior to oppose JSF. :D

[wsoul2k]

Another sugestions:

 

 

 

Dont know... but im sure i can see 4 bay doors on that picture 2 in the front part and other 2 in the rear..... all of then between the engines

[A.S]

I don't want to take part (or start it) on the debate about which one is better. Just came across this on mp.net and it's just another way to look at their features:

 

 

http://www.ausairpower.net/APA-NOTAM-081109-1.html

 

nice post !

[Krippz]

I don't want to take part (or start it) on the debate about which one is better. Just came across this on mp.net and it's just another way to look at their features:

 

 

http://www.ausairpower.net/APA-NOTAM-081109-1.html

 

 

That chart is very partisan. How can they score the T-50 on anything when little is known about it's radar, the data link that it will incorporate, the EWS it will use, etc. I mean as far as I am concerned this is merely a tech demonstrator, the Russians have to develop the following:

 

- AESA radar with LPI and possibly multi-antenna suite

- brand-new jet engines enabling supercruise

- integrated electro-optical IRST/EW suite (DAS + EOTS)

- integrated self-protection and jamming system (Barracuda, SPECTRE)

- advanced RAM materials

- net-centric technology

- advanced methods of integration and quality control for all above

 

And keep it at a reasonable cost i.e. <100 million US Dollars. Sukhoi has a huge task in front of them and almost everything is contingent upon the Indians following through with money.

[Bucic]

F-22 agility yes(0) / PAK-FA (+1) , final score 2 to 5 for PAK-FA...

Was this table posted on HAWX forums?

[Griffin]

Was this table posted on HAWX forums?

Militaryphotos.net. It was squashed pretty soon there too.

nice post !

I regret it already. :D

Or should have said "not to be taken seriously".

[A.S]

i found it interesting at least.....i mean ..erm..is it "unpatriotic" not to be a F-22ski fan? .....im unbiased anyways :D

[Lucas_From_Hell]

Bucic, forget the F-22. The table is just to bash the F-35, the rest is irrelevant :music_whistling:

 

Although the table isn't exactly impartial, and exaggerates in some aspects, it's true that, in some fields (such as CAC), the F-35 is a bit behind its proposed opponents.

 

Putting this "J-XX" thing in the middle was a bit ridiculous. You don't have many info around it, so these can be called educated guesses.

 

If someone wants to take this table seriously, we need to ignore all unknown factors from all aircraft.

 

Maybe we should revisit this table after other PAK-FA flight tests, because now it isn't really complete, making any comparison unfair.

[GGTharos]

i found it interesting at least

 

Really?

 

.im unbiased anyways :D

 

Then you would have rolled your eyes at that chart ;)

[Groove]

How did i know that this chart is from http://www.ausairpower.com BEFORE actually reading the link below ! :D

[Pilotasso]

BUMP this thread, cmon guys dont let it die... :)