PAK-FA and FGFA Thread

Austin · Post by **Austin** » 20 Aug 2011 11:17

neerajb wrote:Su-30 MKI of IAF afterburning.

http://www.flickr.com/photos/bwjones/2831576285/

Cheers....

That certainly not the full afterburning , my observation with afterburning is you should see a straight orange/yellow flame from the nozzle.

You see many civilian airline engine producing some flame/glow and those are dry thrust.

neerajb · Post by **neerajb** » 20 Aug 2011 13:15

shiv wrote:The video below shows an Al-31 ground test. At 1 min 08 sec you can see flame deep in the jet pipe without afterburning. At 1:32 you can see what the diameter of the exhaust nozzle is and the intensity of the flame with afterburning.
http://www.youtube.com/watch?v=wsJyC5g4IBo&NR=1

As Vina mentioned, check the radial orange glowing lines inside the tube, they are spray bars spraying fuel and glowing. Jet engines provide variable augementation and so is the nozzle not opened up fully.

IMO this whole glow thing is getting absurd now, my last post on this topic. Everyone can have his/her opinions and I'll stop at that. A civil engine is different from a military leaky turbojet with AB and IIRC we started this debate with PAK FA engines.

@Vina - Very coherrent post, couldn't put all that at one place.

Cheers....

shiv · Post by **shiv** » 20 Aug 2011 16:50

neerajb wrote: IMO this whole glow thing is getting absurd now, my last post on this topic. Everyone can have his/her opinions and I'll stop at that. A civil engine is different from a military leaky turbojet with AB and IIRC we started this debate with PAK FA engines.

Actually no. You were never involved and you never figured out what was being discussed. Maybe you could take a shot at the answer if you did.

The previous page has four videos linked. One of the PAKFA, one each of a Tornado, F-15 and F-22 at airshows. All the aircraft show glowing musharrafs during large parts of the display. Would you judge that the afterburner was on at those occasions? The entire discussion stated with a point related to that.
Would you be willing to state your view?

VishalJ · Post by **VishalJ** » 20 Aug 2011 18:50

Austin wrote: That certainly not the full afterburning , my observation with afterburning is you should see a straight orange/yellow flame from the nozzle.

You see many civilian airline engine producing some flame/glow and those are dry thrust.

While i'm not an expert on this matter but if i may dare to share my limited knowledge in these things.

As many of you know, the Su30 or AL31FP only produces Blue Flames, other blu burners are those of the Tu22M & Tu160

The photo on the left ^ is SB103 on t/o roll down Waddington for Indradhanush 07 & the one on the right ^ is of mine AI 11 just second(s) after rotation.

Point is: Austin i've not seen anything orange/red/magentaish on the Su30s, even at Max burner these stay blue or blueish at best.

I have a popular Album on JP called ΛFTΞЯBUЯИΞЯ
All Red/Orangish burners are predominantly Western, is what i gather.

neerajb · Post by **neerajb** » 20 Aug 2011 19:24

shiv wrote:Actually no. You were never involved and you never figured out what was being discussed.

I know you are talking about the argument on lack of reserve power in PAK FA here. I never argued on that, nor I want to.

Maybe you could take a shot at the answer if you did. The previous page has four videos linked. One of the PAKFA, one each of a Tornado, F-15 and F-22 at airshows. All the aircraft show glowing musharrafs during large parts of the display. Would you judge that the afterburner was on at those occasions? The entire discussion stated with a point related to that. Would you be willing to state your view?

Actually I did and interestingly you replied on that as well and the main point of contention was presence/absence of glow at the nozzle as the proof of AB engagement. By the way, my 'absurd' comment was not aimed at anyone in particular, just that I feel people are arguing for the sake of arguing.

Cheers....

Austin · Post by **Austin** » 20 Aug 2011 19:24

Vishal check the video posted by Shiv on AL-31F from 2:26 to 2:31 one could see yellow/golden flames with what appears to me as full after burner engaged.
http://www.youtube.com/watch?v=wsJyC5g4IBo&NR=1

I think it has some thing to do with throttle settings and on most occasion where its demo to press/public there is probably no need to engage the full after burner when its clean with no payload.

vina · Post by **vina** » 20 Aug 2011 19:51

Austin wrote:Vishal check the video posted by Shiv on AL-31F from 2:26 to 2:31 one could see yellow/golden flames with what appears to me as full after burner engaged.
http://www.youtube.com/watch?v=wsJyC5g4IBo&NR=1

Oh. That is the shots from ONE particular camera from to the slightly behind and to the side, which shows that orangeish color while the camera directly to the side shows a clear blue flame like in a gas stove! My simple explanation is that the white balance in the frames from the camera behind is off and is not showing correct color. Yes.. The SU30 with the burner lit shows a nice blue flame!

Prasad · Post by **Prasad** » 20 Aug 2011 20:29

vina wrote:
Austin wrote:Vishal check the video posted by Shiv on AL-31F from 2:26 to 2:31 one could see yellow/golden flames with what appears to me as full after burner engaged.
http://www.youtube.com/watch?v=wsJyC5g4IBo&NR=1
Oh. That is the shots from ONE particular camera from to the slightly behind and to the side, which shows that orangeish color while the camera directly to the side shows a clear blue flame like in a gas stove! My simple explanation is that the white balance in the frames from the camera behind is off and is not showing correct color. Yes.. The SU30 with the burner lit shows a nice blue flame!

Yep thats partly correct. What is happening is that when viewed from behind the (temp and hence brightness) difference between the interior flames and the background of an evening sky is far greater than the dynamic range of the camera sensor. That is why it appears white and parts reddish compared to the side-on shot showing better colour. Blue is the actual colour and not red/white.

Kanson · Post by **Kanson** » 20 Aug 2011 20:54

Changes in the colour is due to change in pressure/velocity variables of the exhaust gas. The radial orange flame seen behind Su-30 is due to the presence of flame holder ring where the velocity changes.

shiv · Post by **shiv** » 20 Aug 2011 20:55

Austin wrote: http://www.youtube.com/watch?v=wsJyC5g4IBo&NR=1

I think it has some thing to do with throttle settings and on most occasion where its demo to press/public there is probably no need to engage the full after burner when its clean with no payload.

Screen grabs from 1:06 and 1:34. Despite the appearance the nozzle is open wide in the second pic - i.e at 1:34 with the blue dazzle. (Check the width of gaps between white strips on the inside of the A/B nozzle) Same angle. Presumably same camera

The afterburner has kicked in 1:34. What is happening at 1:06?
I

II

vina · Post by **vina** » 20 Aug 2011 21:03

Vishal Jolapara wrote:As many of you know, the Su30 or AL31FP only produces Blue Flames, other blu burners are those of the Tu22M & Tu160
...
All Red/Orangish burners are predominantly Western, is what i gather.

Hmm . Interesting and I am wondering why. Would you know if the AL-31FP and the engines on TU 22M and the TU-160 have mixers ? In any case, the nice blue flame means a well mixed, nice efficient afterburner.

shiv · Post by **shiv** » 20 Aug 2011 21:07

MiG 21, 23, 27 and 29 are all orange.

vina · Post by **vina** » 20 Aug 2011 21:11

Prasad wrote:Yep thats partly correct. What is happening is that when viewed from behind the (temp and hence brightness) difference between the interior flames and the background of an evening sky is far greater than the dynamic range of the camera sensor. That is why it appears white and parts reddish compared to the side-on shot showing better colour. Blue is the actual colour and not red/white.

Oh yes, absolutely.Thanks for thinking of this. Yup, it would be beyond the dynamic contrast range definitely of most color films (I dont dont know how the dynamic contrast of digital sensor is wrt film, I suspect better than film, but I suspect still not enough). With film, the fix is easy, shoot with a gradated filter that darkens the background, bringing the pic back into the contrast , I suspect you would do the same with digital. The basics are the same anyways, aren't they?

vina · Post by **vina** » 20 Aug 2011 21:15

shiv wrote:The afterburner has kicked in 1:34. What is happening at 1:06?

My guess. The spray bars are probably in 2 stations. At 1:34, both the spray bars are putting out fuel , while at 1:06 the ones upstream are on and you see the blue flames from that.. I could be wrong, but I think it is a decent guess

Prasad · Post by **Prasad** » 20 Aug 2011 21:25

vina wrote:
Prasad wrote:Yep thats partly correct. What is happening is that when viewed from behind the (temp and hence brightness) difference between the interior flames and the background of an evening sky is far greater than the dynamic range of the camera sensor. That is why it appears white and parts reddish compared to the side-on shot showing better colour. Blue is the actual colour and not red/white.
Oh yes, absolutely.Thanks for thinking of this. Yup, it would be beyond the dynamic contrast range definitely of most color films (I dont dont know how the dynamic contrast of digital sensor is wrt film, I suspect better than film, but I suspect still not enough). With film, the fix is easy, shoot with a gradated filter that darkens the background, bringing the pic back into the contrast , I suspect you would do the same with digital. The basics are the same anyways, aren't they?

Pretty much. Though better, digital sensors are incapable of handling such a wide range of brightness and we're talking burning jet fuel brightness against evening darkening setting. Modern cameras routinely struggle to accurately expose for a setting/rising sun and foreground combination. One has to bracket the shot or use ND filters as you mentioned. Video cameras are very similar.

Austin · Post by **Austin** » 20 Aug 2011 21:57

This video is quite nice shows a typical yellow flame while take off and displays the T/W ratio in good effect

http://www.youtube.com/watch?v=xsoYm6VkNYo

Austin · Post by **Austin** » 20 Aug 2011 22:01

Kanson wrote:Pls do share these details when and where they are available.

Kanson no details but some news on new engine

State tests of fifth-generation fighter engine to begin in 2013

ZHUKOVSKY, Moscow region, August 19 (Itar-Tass) —— State tests of the engine of the fifth-generation fighter jet will begin in 2013, Lyulka Research Center General Designer Yevgeny Marchukov said.

”Preliminary tests are in progress. About 20 engines have been built. The trials are rather successful, and I think that the state testing program will be launched in 2013,” he noted.

SaiK · Post by **SaiK** » 21 Aug 2011 04:32

would that be the al41 153kN or 180kN wala?

Austin · Post by **Austin** » 21 Aug 2011 15:59

What qualifies an engine to be considered as 5th Gen Engine ?

If i were to check wiki for F119 on F-22 as benchmark for 5th gen Engine , it has a thrust of 156- 160 Kn and T/W ratio of 9:1.

The Saturn designer insist that the current engine 117 qualifies are 5th gen engine ?

So what exactly is the parameter for 5th Gen engine ?

NRao · Post by **NRao** » 21 Aug 2011 16:57

For more about engines (this was posted some pages ago):

May 28, 2011 :: New interview with Al-41F chief designer

I opened the secret and say that we actually already have two 5-th generation engines. The second, which is now conventionally called the "Type 30", has already been tested in flight on the fighter T-50 ". In the future it probably will give the name of "AL-...." According to its parameters it a 15-25 percent better than "117 th".

"Type 30" is the current internal designation for the 117++ engine. Nothing more on Type-30 there..................

SaiK · Post by **SaiK** » 21 Aug 2011 17:52

imu, besides the t:w ratios, the 5th gen engine should be able to provide the required dry thrust to the designed set mach levels for super cruising.

so, it should be all blue on super-cruise!.. and still go yellow-orange-red after burn [well of course, that is debatable in the sense, we still think the color is due to over burn].

Sabyasachi · Post by **Sabyasachi** » 21 Aug 2011 18:23

5th generation fighter aborts flight at MAKS-2011 air show

Strangely reported news.

Austin · Post by **Austin** » 21 Aug 2011 19:46

SaiK wrote:imu, besides the t:w ratios, the 5th gen engine should be able to provide the required dry thrust to the designed set mach levels for super cruising so, it should be all blue on super-cruise!.. and still go yellow-orange-red after burn [well of course, that is debatable in the sense, we still think the color is due to over burn.

Eurofighter engine EJ200 and Su-35 engine 117S provides supercruise capability to both fighter using dry thrust both are 4th or 4 plus gen fighter , on the other hand another 5th gen fighter F-35 with engine F135/F136 cannot provide supercruise capability

Hence supercruise may not be the only criteria to call an engine 5th Gen

Philip · Post by **Philip** » 21 Aug 2011 19:57

The simplest solution would be to replace all the MIG-27 UGs,MIG-21 Bisons,Jaguar UGs,etc.,with a new aircraft that is a follow on to the LCA Mk-1 and 2.A steady progression of the LCA project would result in success with "incremental",not revolutionary devlopment with an entirely new aircraft.One can see that there will be a demand for a smaller multi-role stealth aircraft to replace a few hundred of these legacy types.In the next decade,the use of stealthy UCAVs and stealth aircraft will predominate and the $++ gen. aircraft will be found lacking in comparison with newer stealth types like the FGFA,F-22,JSF,J-20,etc.

See how carefully Russia is developing its own T-50/FGFA for us.It developed the SU-27 into the SU-30/30MKI and then further developed it into the SU-35,with more advanced tech and fitted systems that would be on the FGFA as part of the SU-35 package.So when the FGFA flies,it will already have perfected weapon systems and sensors and other eqpt. which have already been validated on the SU-35.

If we use the LCA programme as a stepping stone to the MCA it will make sense.Otherwise,we will be trying to "reinvent the wheel" ,with another "new" design,and deluding ourselves into thinking that the MCA/AMCA or whatever it will be called is entirely indigenous after using the FGFA which willa rrive long before the MCA/AMCA whatever!

SaiK · Post by **SaiK** » 21 Aug 2011 20:08

The generation speak is an aspect of the fighter itself, and not specific to the engine is my understanding.. so, besides super cruise, it could be many from:-

- MTBF or overhaul.
- T:W
- Reduced Weight itself, from advanced materials.
- Reduced IR signature or devices to reduce the IR.
- not sure about flat rating? and it also depends on IAF requirements, in the sense can't tank at sea level or humid conditions, and able to take off from leh or higher altitude runways.

and generations can also include requirements specific features like variants in VTOL trubofan integration, all aspect fadec, etc.

how about considering reverse thrusters much before combustion chambers? possible? fangs out from top, bottom or sides, and releases the thrust.

shiv · Post by **shiv** » 21 Aug 2011 20:13

I find this expression "5 gen engine" an odd one. To have a 5th gen engine one needs definitions for 1, 2, 3 and 4th gen engines. Maybe the man meant engine for a 5 gen fighter.

Considering that HF 24 could supercruise I don't think a special "5h Gen engine" is what is necessary for supercruise. But I guess a 5 gen fighter would need reliable, lean burning efficient engine that can not help the a/c cruse supersonic but also respond like a fighter engine for sudden demands in thrust and ruggedness. Apart from civilian airliner engine like reliability and acceptable performance at a range of altitudes, high MTBF, self diagnostics, easy maintainability under harsh conditions.Should be able to swallow some smoke and dust and still feel OK.

Maybe I am asking for heaven and earth. Just a guess...

Singha · Post by **Singha** » 21 Aug 2011 21:23

> lean burning, rapid throttling up and down
> civilian airliner engine like reliability and acceptable performance at a range of altitudes,
> high MTBF, self diagnostics, easy maintainability under harsh conditions.

all of that is already there in most good 4th gen engines like EJ200 / F414 / M88 et al.

to me the term 5th gen engine is even more ambiguous than the 5th gen fighter fight we have been through.

T:W ratio could be a parameter, just high raw thrust alone cannot be - there are plenty of older gen engines like the D-30 on Mig31 that provide huge thrust levels. a small jet trainer engine could be 5th gen too if reqd parameters were met.

materials used could be a parameter - but I am sure the EDE/EPE 414, M88-4 , EJ220 would be using the same exotic materials that a more greenfield design like F119/F136 did..these are infact newer proposed engines than the F119/F136 and could be more advanced in science and engineering terms.

SaiK · Post by **SaiK** » 22 Aug 2011 00:59

So, going by F119, we could then say these along with TVC:-

Features
http://www.globalsecurity.org/military/ ... 2-f119.htm

Integrally bladed rotors: In most stages, disks and blades are made from a single piece of metal for better performance and less air leakage.
Long chord, shroudless fan blades: Wider, stronger fan blades eliminate the need for the shroud, a ring of metal around most jet engine fans. Both the wider blades and shroudless design contribute to engine efficiency.
Low-aspect, high-stage-load compressor blades: Once again, wider blades offer greater strength and efficiency.
Alloy C high-strength burn-resistant titanium compressor stators: Pratt & Whitney's innovative titanium alloy increases stator durability, allowing the engine to run hotter and faster for greater thrust and efficiency.
Alloy C in augmentor and nozzle: The same heat-resistant titanium alloy protects aft components, permitting greater thrust and durability.
Floatwall combustor: Thermally isolated panels of oxidation-resistant high cobalt material make the combustion chamber more durable, which helps reduce scheduled maintenance.
Fourth-generation full-authority digital electronic engine control (FADEC): Dual-redundant digital engine controls - two units per engine, two computers per unit - ensure unmatched reliability in engine control systems. The same experience that introduced full-authority digital control to fighter engines works with the aircraft system to make engine and aircraft function as a single flight unit.
No visible smoke: Reduces the possibility of an enemy visually detecting the F-22.
Improved Supportability: All components, harnesses, and plumbing are located on the bottom of the engine for easy access, all line replaceable units (LRUs) are located one deep (units are not located on top of one another), and each LRU can be removed with just one of the six standard tools required for engine maintenance.

negi · Post by **negi** » 22 Aug 2011 01:46

Al-31++ generation have higher BPR than any of their western counterparts not sure if that contributes to the blue flame though, ideally during full reheat the flame colour should turn from blue>yellow spectrum as the combustion won't be complete in an ideal sense (not all the fuel dumped in the nozzle will get burnt).

PratikDas · Post by **PratikDas** » 22 Aug 2011 02:00

Hindustan Times: Indo-russian stealth fighter project hits turbulence {Not really}

"The T-50 fighter aborted the take-off for technical reasons due to engine overflow and its pilot Sergei Bogdan decided to apply emergency brakes with the tail parachute," Interfax reported quoting defence industry sources.

SaiK · Post by **SaiK** » 22 Aug 2011 03:12

Be thankful that nothing unforeseen happened as predicted by our Austin here... wow, quite a close call from him.

raja_m · Post by **raja_m** » 22 Aug 2011 04:35

5th generation fighter aborts flight at MAKS-2011 air show

http://en.rian.ru/russia/20110821/166002069.html

PratikDas · Post by **PratikDas** » 22 Aug 2011 04:55

SaiK wrote:Be thankful that nothing unforeseen happened as predicted by our Austin here... wow, quite a close call from him.

Absolutely. Sergey Bogdan in control.

Source: El Hangar De TJ

Source: Chindits

SaiK · Post by **SaiK** » 22 Aug 2011 05:19

those flames doesn't look good at all.. anyways, it is good that they have something now for corrections.. it is better than a hidden defect.

Singha · Post by **Singha** » 22 Aug 2011 08:00

well atleast we now know it can produce yellow flame too!

suryag · Post by **suryag** » 22 Aug 2011 08:58

nazar lag gayi bhaiyon t-50 ko

Austin · Post by **Austin** » 22 Aug 2011 11:20

Rear view PAK-FA

http://www.sukhoi.ru/forum/attachment.p ... 1313952764

PratikDas · Post by **PratikDas** » 22 Aug 2011 11:38

Austin wrote:Rear view PAK-FA

http://www.sukhoi.ru/forum/attachment.p ... 1313952764

Menacing, to say the least. The aperture of the rear-facing radar will be quite substantial once integrated! Just what the doctor ordered.

Austin · Post by **Austin** » 22 Aug 2011 17:23

Pictures of PAK-FA engine flame out reportedly FADEC malfunction

http://farm7.static.flickr.com/6073/606 ... c450_o.jpg
http://img52.imageshack.us/img52/121/img6607h.jpg

SaiK · Post by **SaiK** » 22 Aug 2011 17:46

sounds like a wrong way to dump fuel.