Bharat Rakshak Forum Announcement

Hello Everyone,

A warm welcome back to the Bharat Rakshak Forum.

Important Notice: Due to a corruption in the BR forum database we regret to announce that data records relating to some of our registered users have been lost. We estimate approx. 500 user details are deleted.

To ease the process of recreating the user IDs we request members that have previously posted on the BR forums to recognise and identify their posts, once the posts are identified please contact the BRF moderator team by emailing BRF Mod Team with your post details.

The mod team will be able to update your username, email etc. so that the user history can be maintained.

Unfortunately for members that have never posted or have had all their posts deleted i.e. users that have 0 posts, we will be unable to recreate your account hence we request that you re-register again.

We apologise for any inconvenience caused and thank you for your understanding.

Regards,
Seetal

Kaveri & aero-engine discussion

The Military Issues & History Forum is a venue to discuss issues relating to the military aspects of the Indian Armed Forces, whether the past, present or future. We request members to kindly stay within the mandate of this forum and keep their exchanges of views, on a civilised level, however vehemently any disagreement may be felt. All feedback regarding forum usage may be sent to the moderators using the Feedback Form or by clicking the Report Post Icon in any objectionable post for proper action. Please note that the views expressed by the Members and Moderators on these discussion boards are that of the individuals only and do not reflect the official policy or view of the Bharat-Rakshak.com Website. Copyright Violation is strictly prohibited and may result in revocation of your posting rights - please read the FAQ for full details. Users must also abide by the Forum Guidelines at all times.
chola
BRFite
Posts: 1737
Joined: 16 Dec 2002 12:31
Location: USA

Re: Kaveri & aero-engine discussion

Postby chola » 14 Sep 2017 13:50

Writing in the Iran thread and noting that the Iranians had RE the J-85 turbojet as the powerplant for their Saqeah F-5 clones lit a light bulb over my head. Would it have made more sense for us to cut our teeth on a simpler turbojet engine like the Tumansky 25 (which we had been licensed to build for the Bisons)?

Going all out for a modern turbofan was a bigger bite than we could chew without a foundation. That doomed the Kaveri from the start. If Iranians can build an engine for a fighter under extreme embargo then we should be able to as well. It is just a matter of selecting a realistic initial goal.

brar_w
BRF Oldie
Posts: 6002
Joined: 11 Aug 2016 06:14

Re: Kaveri & aero-engine discussion

Postby brar_w » 14 Sep 2017 14:59

Austin wrote:
brar_w wrote:No it does not. Notice what jay was referring to - the EJ-200, F414 etc etc etc. He was not talking about the Typhoon, Super Hornet, Gripen, LCA etc. The engines did not dogfight each other, the aircraft did. He was specifically referring to the engine technology.


You cant seperate Engine Technology needed for TVC because a lot of low speed flights and high angle of attack afforded by TVC where your air intake is sucked of air/oxygen but engine still has to to be robust enough to keep working without flaming out , If they try to do MKI like low speed charactesistics and extereme manouverability with TVC chances are the engine will just flame out.

TVC is not something you can randomly fit into any engine without understanding how engine will work in all the regiems of flight and high AOA or NO AOA , this is something an aircraft engine does it but TVC just extends the benchmark to another level


OK. So because the Eurofighter Typhoon does not have TVC, its engine is inferior in some way because it does not come with a vectoring nozzle because who knows it may not be able to support high alpha flight regime if the aircraft is properly designed to perform at those regimes. Some logic there boss but whatever floats your boat.

Good thing then that they didn't take their TV nozzle out of the lab, who knows maybe the engine would have not been able to support performance in the PS regime and would have flamed out :wink: . I guess Lockheed and GE really lucked out with the AVEN, some 15 years ago where they integrated a multi axis TV system on an F-16 and its FCS and were able to do cobras and explore the high alpha regime successfully without flaming out. I guess they can now claim to have a superior engine to the EJ which was really designed around high T2W, and dry thrust for supercruise since engines are designed to support a mission requirement.

As Jay points out, if you want to do better in the PS regime, TV helps but so do a host of other things. The YF22 was designed to meet the sustained alpha requirements of the ATF program without TVC. Designers left those big control surfaces out there because they feared that the USAF would come in and ask them to not pursue TVC so they wanted to demonstrate performance independent of it. Northrop did demonstrate on their aircraft even without TV. If the Typhoon wants to do better in that department, it has other potential solutions and those have been written about earlier. It also has the ultimate solution of incorporating a multi-axis vectoring nozzle which they have lab tested over the years. But those are airframe performance requirements and design trades. What we were basically discussing was the technology and its impact on engines specifically, the higher thrust to weight ratios, and higher thrust availability in military settings. Clearly the EJ-200 is one of the leading engines in this category, and it not having TVC does not take anything away form it but may from the Typhoon which may be inferior in that slow and high alpha regime compared to many other aircraft out there.

https://www.youtube.com/watch?v=ss96tsbG5KY

JayS
Forum Moderator
Posts: 2718
Joined: 11 Aug 2016 06:14

Re: Kaveri & aero-engine discussion

Postby JayS » 16 Sep 2017 00:10

Saw a tender for Turbine Blisk by GTRE. Specs for it are:

air flow = 5kg/sec
RPM = 35000
Max Op Temp = 1000deg C

Looks like Manik to me.

NRao
BRF Oldie
Posts: 15868
Joined: 01 Jan 1970 05:30
Location: Illini Nation

Re: Kaveri & aero-engine discussion

Postby NRao » 24 Sep 2017 03:05


JayS
Forum Moderator
Posts: 2718
Joined: 11 Aug 2016 06:14

Re: Kaveri & aero-engine discussion

Postby JayS » 02 Oct 2017 09:55

http://www.thehindu.com/business/Indust ... 9.ece/amp/

Read and understand challenges provided by Indian conditions. Sorry excuse given by PW though. They would have known all the operating conditions beforehand and their design couldnt handle it still. The engine will be improved in time, but keep this in mind, where OEMs like PW struggle to design good engines for Indian conditions, any desi effort will see similar steeper challenge. Given its design point has to be with Indian conditions its gonna be a notch more difficult.

Eric Leiderman
BRFite
Posts: 328
Joined: 26 Nov 2010 08:56

Re: Kaveri & aero-engine discussion

Postby Eric Leiderman » 09 Oct 2017 23:37

https://www.siemens.com/innovation/en/h ... lades.html

With 3d printing of a gas turbine blade now a reality, Design to manafacturing stage shortened drastically. Maybe this will help us leapfrog in time

ramana
Forum Moderator
Posts: 48099
Joined: 01 Jan 1970 05:30

Re: Kaveri & aero-engine discussion

Postby ramana » 10 Oct 2017 02:26

chola wrote:Writing in the Iran thread and noting that the Iranians had RE the J-85 turbojet as the powerplant for their Saqeah F-5 clones lit a light bulb over my head. Would it have made more sense for us to cut our teeth on a simpler turbojet engine like the Tumansky 25 (which we had been licensed to build for the Bisons)?

Going all out for a modern turbofan was a bigger bite than we could chew without a foundation. That doomed the Kaveri from the start. If Iranians can build an engine for a fighter under extreme embargo then we should be able to as well. It is just a matter of selecting a realistic initial goal.


GTRE started with a turbojet called GTX-37(?). And built it. Janes used to have pictures and descriptions.

This morphed into Kaveri Turbofan.

It just that GTRE did not understand the challenges and did not scream for help when they needed it. Nor did the project reviewers from DRDO, IAF and MoD. There are three levels of reviewers for each project. Not one said this one needs help by way of funds, expertise or facilities.

Total passive oversight.

Its those guys who should be blamed.
When you are in a review panel its because the government trusts your expertise and to be a passive observer is just wasting taxpayer money and the GOI trust.
The GTRE folks were trying something for first time and can be excused for that.
Am sure if they were successful the reviewers would jump in can claim success.

I have not seen one honest appraisal of the Kaveri saga from the ex-GTRE folks or the review folks.

suryag
Forum Moderator
Posts: 2941
Joined: 11 Jan 2009 00:14

Re: Kaveri & aero-engine discussion

Postby suryag » 10 Oct 2017 11:57

Asking for help is a sign of strength

negi
BR Mainsite Crew
Posts: 12908
Joined: 27 Jul 2006 17:51
Location: Trying to mellow down :)

Re: Kaveri & aero-engine discussion

Postby negi » 10 Oct 2017 12:01

Decisions made only reflect the environment ; for Iranians it was a matter of life or death for us on the other hand there is always a "default" go to Plan B i.e. import the damn thing for it will always work ; once you have a plan B in place plan A if challenging will mostly fail.

Pratyush
BRF Oldie
Posts: 7528
Joined: 05 Mar 2010 15:13

Re: Kaveri & aero-engine discussion

Postby Pratyush » 10 Oct 2017 17:53

I have asked this question multiple times . Will ask once again.

It was known ny 2009 /10 that Kaveri will not work out for the Tejas. When it was delinked from the program.

Why was a new effort not launched by GOI to build a replacement taking into consideration all the lessons learn from kaveri.

Also for the AMCA no efforts are being made for the design of a new engine.

chola
BRFite
Posts: 1737
Joined: 16 Dec 2002 12:31
Location: USA

Re: Kaveri & aero-engine discussion

Postby chola » 10 Oct 2017 19:07

Pratyush wrote:I have asked this question multiple times . Will ask once again.

It was known ny 2009 /10 that Kaveri will not work out for the Tejas. When it was delinked from the program.

Why was a new effort not launched by GOI to build a replacement taking into consideration all the lessons learn from kaveri.

Also for the AMCA no efforts are being made for the design of a new engine.



That is easily answered. If the replacement engine is to be a turbofan then why not just continue with the Kaveri? A new turbofan taking all the lessons learned from the kaveri is just a continuation of the kaveri!

The problem is not mismanagement of the Kaveri program. The problem is the simple fact that we just do not have the manufacturing foundation for a turbofan yet. Setting up a new project team won’t suddenly create this ability.

Look at the RD-33 where Russia, with all its great experience, is still having problems after four decades of research, development and manufacturing. We were asking for an engine that is equivalent of western-state-of-the-art F404 and M-88. In the 1990s! When even today we do not have an indigenous turbojet, turboprop or even piston engine to fit into aircraft of any class.

Again, perhaps we should have built a mass produced turbojet like the Tumansky on the MiG-21 (not a just demonstration turbojet like the GTX-37.) But then again a turbojet would not have fulfilled the specs we set forth for the LCA so we would have needed to scale down our ambitions to a single-engine design more akin to a fully indigenous Bison perhaps.

The lack of the foundational steps hurts us everywhere and not just at the high end like the LCA and AMCA. If we had a turboprop or even a simple reliable piston engine, the UCAV/UAV development would have come along faster and with more designs instead of just the Rustom I/II.

BTW, I dont fault our ambition on the Kaveri/LCA but that exuberance should have been backed up with more practical designs that the Indian manufacturing and technical base could have supported at the time. Shooting for the moon is not a bad thing, just have a backup plan in case the moon is too far away for the rifle you own.

JayS
Forum Moderator
Posts: 2718
Joined: 11 Aug 2016 06:14

Re: Kaveri & aero-engine discussion

Postby JayS » 10 Oct 2017 20:48

Pratyush wrote:I have asked this question multiple times . Will ask once again.

It was known ny 2009 /10 that Kaveri will not work out for the Tejas. When it was delinked from the program.

Why was a new effort not launched by GOI to build a replacement taking into consideration all the lessons learn from kaveri.

Also for the AMCA no efforts are being made for the design of a new engine.


Unless its a rhetorical question, do you really expect someone will/can answer for that "Why". Or any answer given here will satisfy you..? A book can be written on this or one can simply shake head and ignore thinking "Its like this only in India".

Eric Leiderman
BRFite
Posts: 328
Joined: 26 Nov 2010 08:56

Re: Kaveri & aero-engine discussion

Postby Eric Leiderman » 15 Oct 2017 02:09

P&W are testing a turbo fan engine with a gear box that decelearates the compressor from the turbine, with an estimated 15% gain in efficiency
The reason for reducing the the compressor is the fan tips are have an angular velocity greater than the spped of sound , which causes issues with compressor efficiency.

Sorry for the long winded intro, however if gurus could answer questions.

In a fighter aircraft with a smaller dia for compressor would the efficiencies be comparable? Are any of the major turbo engine OEM's getting something ready for military applications?

a 15 % increase in range would be something to think about.

shiv
BRF Oldie
Posts: 33961
Joined: 01 Jan 1970 05:30
Location: Pindliyon ka Gooda

Re: Kaveri & aero-engine discussion

Postby shiv » 15 Oct 2017 07:58

Eric Leiderman wrote:
In a fighter aircraft with a smaller dia for compressor would the efficiencies be comparable? Are any of the major turbo engine OEM's getting something ready for military applications?

a 15 % increase in range would be something to think about.


By no means a guru - but I try to keep up with what is happening on the engines side of things.

Do not expect anything similar to happen for military engines for several reasons

1. The "efficiency" that they aim for in civil engines is for the engine to run at pretty much constant speed and the most efficient altitude. They are not looking for sudden changes in RPM and altitude that military engines require (except transports maybe). Sudden changes in RPM, surges or power etc could end up being a real headache for the reduction gearbox.

2. Civil engines are made efficient by the realization that a "core" (narrow) engine has the potential to develop far faar more power if the fans could be much broader and bypass air around the engine - this is the reason for the wide-mouthed "Aaaaaaaaaah" engines in civil air liners. But those broader fans with longer fan blades have traditionally been made to turn at a speed that is controlled by the core engine itself - using a common central shaft. The longer blades spinning faster were more likely to go supersonic at the tips as a result restricting the RPM of the core engine itself. If a real kick-ass gearbox could be made to reduce the speed of the broader "fan" section - efficiency can be improved allowing the core engine to run faster and hotter , but the engine faceitself also becomes very broad with long fan blades and not compact as is more desirable for a space-challenged combat aircraft where you cannot simply hang a broad faced "Aaaaaaaaah" saying engine off the wings like Boeing or Airbus. The Boeing 777 engines are particularly "Aaaaaaaah!" wide open - a man can stand at the engine entrance and hope the pilot does not press the "aage chalo" button or whatever

3. The long fan blades of high bypass engines have more inertia and take more time to spool up to higher RPM. This is fine for a civil airliner that does not need to accelerate suddenly - but useless for a military jet that may have to go for sudden acceleration and deceleration and airflow changes. For example the "tailslide" of the MiG 29 and other aircraft - the plane is made to zoom up vertically on full power + afterburner - and then the engine is cut off to a much lower power setting to it stops climbing, slows down and starts sliding backwards and down.

The A 320 crash in Bengaluru in the1980s (in which we lost some friends) resulted from the fact that the pilot (I think) found himself too low on the approach and tried to spool up the engines (increase power) - but those efficient high-bypass engines needed 15 seconds to reach full power. Contrast that with airshows where a fighter simply turns around, lines up and lands like the pilot needs to go to toilet urgently. Most fighter engines tend to have low bypass ratios that are less efficient that staid civil engines in terms of fuel burning, more compact in size and better capable of sudden acceleration and deceleration

shiv
BRF Oldie
Posts: 33961
Joined: 01 Jan 1970 05:30
Location: Pindliyon ka Gooda

Re: Kaveri & aero-engine discussion

Postby shiv » 15 Oct 2017 08:06

Pratyush wrote:Why was a new effort not launched by GOI to build a replacement taking into consideration all the lessons learn from kaveri.

Who in India would GoI have approached to make a new engine?

1.Ask GTRE that had already taken decades and failed?
2. Ask HAL which has never designed a de novo engine?
3. Ask Infosys/WIPRO/Kirloskar/L&T/Tata/Mahindra who have never built a jet engine ever?
4. Approach SNECMA, GE, Pratt and Whiney, Safran, Klimov, Tumansky, Rolls Royce etc who have built engines for 70 years.

What we have now is 2 and 4. HAL is building 2 engines and they have asked for phoren help in other cases

JayS
Forum Moderator
Posts: 2718
Joined: 11 Aug 2016 06:14

Re: Kaveri & aero-engine discussion

Postby JayS » 15 Oct 2017 09:48

Eric Leiderman wrote:P&W are testing a turbo fan engine with a gear box that decelearates the compressor from the turbine, with an estimated 15% gain in efficiency
The reason for reducing the the compressor is the fan tips are have an angular velocity greater than the spped of sound , which causes issues with compressor efficiency.

Sorry for the long winded intro, however if gurus could answer questions.

In a fighter aircraft with a smaller dia for compressor would the efficiencies be comparable? Are any of the major turbo engine OEM's getting something ready for military applications?

a 15 % increase in range would be something to think about.


I guess you are talking about PW1000G series. In that case the one engine is already in service. Two are in advanced flight testing and will be in service by 2020-21. One more will come eventually.

It has gear box to reduce speed of Fan not compressor. The Gearbox connects LP shaft to Fan. Reduction ratio is about 3:1. LP Compressor is different, and Fan is different module in Civil engines. In mil engines Fan is part of LPC or Booster.

Civil and military engines are designed with very different design goals and seat on a different part of Turbofan spectrum now. Its difficult to compare efficiency based on single parameter namely diameter.

There is no publically know program for use of GTF in Mil engines. Mil engies are moving towards Adaptive or Variable cycle operations. Efficiency and cost is not of paramount importance in Mil engines, performance and reliability are.

chetak
BRF Oldie
Posts: 15951
Joined: 16 May 2008 12:00

Re: Kaveri & aero-engine discussion

Postby chetak » 15 Oct 2017 12:08

shiv wrote:
The A 320 crash in Bengaluru in the1980s (in which we lost some friends) resulted from the fact that the pilot (I think) found himself too low on the approach and tried to spool up the engines (increase power) - but those efficient high-bypass engines needed 15 seconds to reach full power. Contrast that with airshows where a fighter simply turns around, lines up and lands like the pilot needs to go to toilet urgently. Most fighter engines tend to have low bypass ratios that are less efficient that staid civil engines in terms of fuel burning, more compact in size and better capable of sudden acceleration and deceleration


The pilots had a huge fight in the cockpit prior to take off from Bombay because due to a last minute and unannounced crew substitution, a " junior" was to ride check on his "senior".

This was when the airbus was a new entrant to the airline and the envelope protected entity was an ill understood concept among flight crews.

After the fight, all communications ceased between the cockpit crew who were both command rated.

Approach to BLR was made in the wrong mode, a mistake that was not caught by both crew and they wound in an unrecoverable situation quite close to the ground. The pilot opened throttle and also pulled back on the "stick".

the V2500 engines, like all other big engines has a time lag before they spool up (about 6-8 seconds) and deliver the demanded power, unlike a turboprop where power delivery is almost instantaneous.

In the meanwhile, back at the ranch, the envelope protected software suppressed the nose up command because, at that height, it had determined that the tail would have struck the ground had it allowed the sharp nose up attitude that was required.

This fatal accident was decided in Bombay, even before takeoff and it was just looking for a place to happen.

Around this time, give or take, an airbus "test" pilot also mushed into the ground during an airshow demonstration because even he hadn't quite grasped the fundamentals of an "envelope" protected aircraft.

I have seen hundreds of routine analyses of many many airline flight data recorders and it is surprising as to how many command qualified pilots still don't seem to get or even understand envelope protection.

Rishi_Tri
BRFite -Trainee
Posts: 81
Joined: 13 Feb 2017 14:49

Re: Kaveri & aero-engine discussion

Postby Rishi_Tri » 15 Oct 2017 20:53

chetak wrote:
shiv wrote:
The A 320 crash in Bengaluru in the1980s (in which we lost some friends) resulted from the fact that the pilot (I think) found himself too low on the approach and tried to spool up the engines (increase power) - but those efficient high-bypass engines needed 15 seconds to reach full power. Contrast that with airshows where a fighter simply turns around, lines up and lands like the pilot needs to go to toilet urgently. Most fighter engines tend to have low bypass ratios that are less efficient that staid civil engines in terms of fuel burning, more compact in size and better capable of sudden acceleration and deceleration


The pilots had a huge fight in the cockpit prior to take off from Bombay because due to a last minute and unannounced crew substitution, a " junior" was to ride check on his "senior".

This was when the airbus was a new entrant to the airline and the envelope protected entity was an ill understood concept among flight crews.

After the fight, all communications ceased between the cockpit crew who were both command rated.

Approach to BLR was made in the wrong mode, a mistake that was not caught by both crew and they wound in an unrecoverable situation quite close to the ground. The pilot opened throttle and also pulled back on the "stick".

the V2500 engines, like all other big engines has a time lag before they spool up (about 6-8 seconds) and deliver the demanded power, unlike a turboprop where power delivery is almost instantaneous.

In the meanwhile, back at the ranch, the envelope protected software suppressed the nose up command because, at that height, it had determined that the tail would have struck the ground had it allowed the sharp nose up attitude that was required.

This fatal accident was decided in Bombay, even before takeoff and it was just looking for a place to happen.

Around this time, give or take, an airbus "test" pilot also mushed into the ground during an airshow demonstration because even he hadn't quite grasped the fundamentals of an "envelope" protected aircraft.

I have seen hundreds of routine analyses of many many airline flight data recorders and it is surprising as to how many command qualified pilots still don't seem to get or even understand envelope protection.


A Lil OT but still recall the images and remember reading detailed report on this. Of course, at least in airliners the communication between pilots perhaps plays the largest role as evidenced in so many unfortunate incidents that are well documented.

As to the more 'mechanical' cause (I am no A320 expert nor claim to be one), the report stated that the aircraft was in 'Open Descent Mode' which prevented the engines from being powered up. So, though the commander, powered up the engine didn't respond and rest of the sequence happened. The commander, despite communication breakdown in cockpit, would have known from his experience that he was not in best approach. The report further stated that had the aircraft been in 'full power on mode' it would not have happened. Think this incident served to bring about changes in instructions and when to engage / disengage different modes. Tks

chetak
BRF Oldie
Posts: 15951
Joined: 16 May 2008 12:00

Re: Kaveri & aero-engine discussion

Postby chetak » 15 Oct 2017 21:26

Rishi_Tri wrote:
chetak wrote:
The pilots had a huge fight in the cockpit prior to take off from Bombay because due to a last minute and unannounced crew substitution, a " junior" was to ride check on his "senior".

This was when the airbus was a new entrant to the airline and the envelope protected entity was an ill understood concept among flight crews.

After the fight, all communications ceased between the cockpit crew who were both command rated.

Approach to BLR was made in the wrong mode, a mistake that was not caught by both crew and they wound in an unrecoverable situation quite close to the ground. The pilot opened throttle and also pulled back on the "stick".

the V2500 engines, like all other big engines has a time lag before they spool up (about 6-8 seconds) and deliver the demanded power, unlike a turboprop where power delivery is almost instantaneous.

In the meanwhile, back at the ranch, the envelope protected software suppressed the nose up command because, at that height, it had determined that the tail would have struck the ground had it allowed the sharp nose up attitude that was required.

This fatal accident was decided in Bombay, even before takeoff and it was just looking for a place to happen.

Around this time, give or take, an airbus "test" pilot also mushed into the ground during an airshow demonstration because even he hadn't quite grasped the fundamentals of an "envelope" protected aircraft.

I have seen hundreds of routine analyses of many many airline flight data recorders and it is surprising as to how many command qualified pilots still don't seem to get or even understand envelope protection.


A Lil OT but still recall the images and remember reading detailed report on this. Of course, at least in airliners the communication between pilots perhaps plays the largest role as evidenced in so many unfortunate incidents that are well documented.

As to the more 'mechanical' cause (I am no A320 expert nor claim to be one), the report stated that the aircraft was in 'Open Descent Mode' which prevented the engines from being powered up. So, though the commander, powered up the engine didn't respond and rest of the sequence happened. The commander, despite communication breakdown in cockpit, would have known from his experience that he was not in best approach. The report further stated that had the aircraft been in 'full power on mode' it would not have happened. Think this incident served to bring about changes in instructions and when to engage / disengage different modes. Tks


This seniority/juniority nonsense, excessive deference towards authority, the absolute unwillingness to challenge authority, even when the captain/senior does wrong, is a very peculiar asian character flaw and social phenomena. It has led to many a fatal accident.

The last major and fatal CRM eff up in India was the AI express boeing crash in mangalore.

Remember the incident where an engineer was sucked into the aircraft engine at Bombay??

According to an eyewitness, it appeared that the flight captain may have started the engine before the clearance, though officials could not confirm this immediately.

Subramanian was near the nose wheel along with the pushcart when the engine started and he was sucked in.


this was also another CRM failure.

elsewhere this would probably come under Culpable homicide, not amounting to murder.

There is a process called "CRM, cockpit resource management" which is taught to all airline air crew which is supposed to take care of smooth and fail safe crew interaction, communication and cooperation in the cockpit.

Cybaru
BRFite
Posts: 1950
Joined: 12 Jun 2000 11:31
Contact:

Re: Kaveri & aero-engine discussion

Postby Cybaru » 18 Oct 2017 06:09

IAF doesn't seem to be happy with Russian engines from all indication. It doesn't think Russia is materially as well functionally.

Is there any way we could start working with Safran and RR on multiple engine projects that would end up powering the next generation of our fighters and helicopters?

For us GTRE isn't there yet. And perhaps they have a long way to go, but still it should be possible to do what we are doing for Tejas and start working for future projects from get go like AMCA, PAKFA, MKI Super-30, Mig29 and mig29K. This is one project we should throw as much money as possible. 60% control on our engine is far better than zero percent control.

Navy and Indian Railways would benefit hugely as well.

ramana
Forum Moderator
Posts: 48099
Joined: 01 Jan 1970 05:30

Re: Kaveri & aero-engine discussion

Postby ramana » 18 Oct 2017 22:02

The problem to me is the Research mentality of GTRE (Gas Turbine Research Establishment).

Asking them to design an engine is wrong task.
They can do research and their papers are among the best in the world but design requires a different mindset.
Its not there in the GTRE.
The same attitude hinders DRDO.

If you note DRDO greatest success was when Kalam was in charge.
He was a technologist and not a researcher.

You cant innovate what you don't make.


Maybe the GTRE should be confined to pure research and the design group split away and work with HAL Engine division to ensure things get innovated.

If needed it can have design engineers from HAL also in it.

Call it Gas Turbine Engine Design Group.

Not a Laboratory.

Current model is unsustainable and worse unproductive.

Vivek K
BRFite
Posts: 1788
Joined: 15 Mar 2002 12:31

Re: Kaveri & aero-engine discussion

Postby Vivek K » 19 Oct 2017 06:57

You're right. HAL's Engine Division should collect its specialists and take the people closest to the Kaveri and spin this into an Hindustan Jet Engine (HJE) Manufacturing Company. And the research minded folks with GTRE should be sent to Midhani and given GOI support to build a company called Defense Metallurgy Ltd.

That would be much better than GTRE. But one of their tasks should be to duplicate the performance of a bison engine (Tumansky R-25?) before starting on the Kaveri.

ramana
Forum Moderator
Posts: 48099
Joined: 01 Jan 1970 05:30

Re: Kaveri & aero-engine discussion

Postby ramana » 19 Oct 2017 07:28

Vivek K we have convergence!!!

I know you are an engineer.
Can you write a policy paper on this focusing on the need, synergies, and benefits and why current mode is not working.
I would rather they work on Jaguar or Mig-29 engines as the Bisons will get phased out.
Modern engine with the same footprint and FADEC with longer life.

Pratyush
BRF Oldie
Posts: 7528
Joined: 05 Mar 2010 15:13

Re: Kaveri & aero-engine discussion

Postby Pratyush » 19 Oct 2017 13:33

I have seen multiple posts regarding the need to work on a previous generation engine. If we are going to work on copying a jet engine, why not copy the 404. Which will have future application for the IAF.

chola
BRFite
Posts: 1737
Joined: 16 Dec 2002 12:31
Location: USA

Re: Kaveri & aero-engine discussion

Postby chola » 19 Oct 2017 16:12

Pratyush wrote:I have seen multiple posts regarding the need to work on a previous generation engine. If we are going to work on copying a jet engine, why not copy the 404. Which will have future application for the IAF.


Because the F404 is a turbofan like the Kaveri and we cannot build the Kaveri. The same goes for the Adour and RD-33 from the Jag and MiG-29 respectively.

Unlike a simpler turbojet, a turbofan has the intricate fan section in front as well as the bypass tube surrounding the the core.

Those two sections mentioned makes it far more expensive and so requires a turbofan to last longer which in turn requires the development of advance materials — which even the Russians have issues with today in the RD-33 and AL-31.

Look at the Iranian example. They are able to RE the J-85 turbojet from the F-5 for their Saqaeh but they are not able to do the same for the early generation F-110 turbofan of the F-14. It is many magnitudes harder. But by building a turbojet that can power production fighters Iran is productionizing the core for any future turbofan. The heart or core of any turbofan is a turbojet.

So a production turbojet is a foundational step we should take and targeting a Tumansky-like engine is an very achievable goal at our current level of development, especially in manufacturing.

I would go further back on the technical rung to turboprop and even pistons where we are not dealing high temperatures though those have their own intracies. The fact we have not master productionizing even those technically less advance engines mean we are attempting a turbofan with no foundation, i.e. in American parlance a moonshot.

And don’t think the lack of turbojet, turboprop and piston haven’t play havoc with our development elsewhere. We cannot even build prototype drones without importing a Lycoming piston for Rustom I or a Saturn turboprop for Rustom II. It is stifling our ability to build any aircraft from cropdusters to UAVs. We are so in intent with the high level stuff like 4th gen fighters that we forgo the huge range of aircraft that doesn’t require a state of the art turbofan.

The reason why Cheen is able to develop endless models of drones (not to mention cropdusters and light utility planes) and sell them everywhere is their companies have a readily available supply of local pistons and turboprops. They don’t have to import a fvcking piston for a goddam drone prototype like we needed to do.

Do the needful and build our foundation, please.

Vivek K
BRFite
Posts: 1788
Joined: 15 Mar 2002 12:31

Re: Kaveri & aero-engine discussion

Postby Vivek K » 19 Oct 2017 18:53

ramana wrote:Vivek K we have convergence!!!

I know you are an engineer.
Can you write a policy paper on this focusing on the need, synergies, and benefits and why current mode is not working.
I would rather they work on Jaguar or Mig-29 engines as the Bisons will get phased out.
Modern engine with the same footprint and FADEC with longer life.

Will give it a shot Ramana!

Vivek K
BRFite
Posts: 1788
Joined: 15 Mar 2002 12:31

Re: Kaveri & aero-engine discussion

Postby Vivek K » 19 Oct 2017 20:18

Chola you are absolutely spot on. Working and failing at the Kaveri is not too bad. However, not producing an R-25 style afterburning Turbojet for a country the size of India is perhaps criminal and treasonous! Especially when IAF was having spares issue, to have not stepped in with a turbojet - I would pin a lot of blame on DRDO for the deaths of 100s of pilots.

In the same vein, IAF and DRDO should have worked in the 80s to develop a Mig-21++ (kind of an Iron Bird LCA without the composites but without the high landing speeds of the Mig). They should have also developed twin engined prototypes to study the aerodynamics. A Marut body could have been prepared with two R-13 (R-25 came in later I think) or something similar to be technology demonstrators.

That is why the ADA should be either given more responsibilities in the Aviation sector or merged with HAL. ADA could be charged with building up Taneja Aerospace as a rival to HAL with some production lines for LCA set up with Taneja. NAL should be made a part of Taneja. GOI should use funds from HAL to develop capabilities with Taneja and DRDO should fund Midhani's efforts in metallurgy and also provide talented staff to Midhani for free.

I would love to see HAL/DRDO work on the following:
a) LCA - 500 a/c production (MK1, MK1A, MK II)
b) AMCA - Twin Engined fighter + naval variant (use all the knowledgebase from NLCA) - prototype TD to be in skies in 3-5 years (wishful thinking)
c) Conceptual Design - Long range Bomber to take the fight to distant shores using dedicated aircraft - if India wants to project power away from its shores.
d) AJT and IJT (ongoing - take to completion)
e) AESA and other radars for fighters, AWACS (ongoing presently)
f) 12 more EMB AEWs (wishful thinking)

chola
BRFite
Posts: 1737
Joined: 16 Dec 2002 12:31
Location: USA

Re: Kaveri & aero-engine discussion

Postby chola » 19 Oct 2017 20:44

^^^ That is a great point wih the deadly issue of MiG-21 spares and the high landing speed of the 21 itself. Necessity alone should have made us look into building a turbojet and reworking a modernized MiG-21 equivalent. But probably a combination of contract obligations — Russia would never allow us to put another engine into the MiG-21s we were assembling — and simply wanting the latest and greatest (FBW, composite and turbofan) kept us from doing so. All things and attitude that need to be fixed.

When you talk about AEW, look at this:
Image

A carrier aircraft for the tip of a superpower’s proverbial spear. Powered by the humble turboprop. So could you imagine all the possibilities if we had a production turboprop powering a modest airframe like the Saras? Instead, our Saras prototypes depend on PWs that were subjected to embargo after Pokhran.

Vivek K
BRFite
Posts: 1788
Joined: 15 Mar 2002 12:31

Re: Kaveri & aero-engine discussion

Postby Vivek K » 19 Oct 2017 21:02

True. Need a new company to first develop a turbojet and a line of turboprops - these could also go into the HTT 40.

But why does India care so much for contract obligations - no one else does! Pakistan let the Chinese look inside the F-16, the Chinese REed the Mig-21, the SU-27, the Su-30. Why do we observe regulations that no one else does?

If our CFD staff are sitting around twiddling their thumbs, they should be tasked with modeling the aircraft in IAF inventory and study their aerodynamics and look for improvements. It is time for India to not play stupid anymore.

NRao
BRF Oldie
Posts: 15868
Joined: 01 Jan 1970 05:30
Location: Illini Nation

Re: Kaveri & aero-engine discussion

Postby NRao » 19 Oct 2017 21:44

There was a vid, posted by Brar, on IIRC the f-35. The skunk works engineer mentions that they used to tweak an engine, run it until it failed, figured out why it failed, found a fix and repeated the process until they got an engine they wanted. I think this is a common thread for "engine"s. I doubt there is a way around it. One can do only so much via RE. Flip side, there is no alternative to a local effort.

Also, there is a need to have a team that looks into disruptive techs. Beyond the effort to either complete the Kaveri or dup a F414. The two teams need to constantly hook up to ensure a contemporary engine, one that will be able to stand on its own on some platforms.

And form a base for future engines.

15-20 years IMHO. At least.

Vivek K
BRFite
Posts: 1788
Joined: 15 Mar 2002 12:31

Re: Kaveri & aero-engine discussion

Postby Vivek K » 19 Oct 2017 23:39

NRao wrote:.... One can do only so much via RE. Flip side, there is no alternative to a local effort.

Also, there is a need to have a team that looks into disruptive techs. Beyond the effort to either complete the Kaveri or dup a F414. The two teams need to constantly hook up to ensure a contemporary engine, one that will be able to stand on its own on some platforms.

And form a base for future engines.

15-20 years IMHO. At least.

If Metallurgy is not a barrier, then RE can help you overcome design challenges. Also, how does it help to say 15-20 years and after the Kaveri experience, does it still take 15 years? Is Kaveri struggling for metallurgy or due to design?

chola
BRFite
Posts: 1737
Joined: 16 Dec 2002 12:31
Location: USA

Re: Kaveri & aero-engine discussion

Postby chola » 19 Oct 2017 23:48

Vivek K wrote:True. Need a new company to first develop a turbojet and a line of turboprops - these could also go into the HTT 40.

But why does India care so much for contract obligations - no one else does! Pakistan let the Chinese look inside the F-16, the Chinese REed the Mig-21, the SU-27, the Su-30. Why do we observe regulations that no one else does?

If our CFD staff are sitting around twiddling their thumbs, they should be tasked with modeling the aircraft in IAF inventory and study their aerodynamics and look for improvements. It is time for India to not play stupid anymore.


Well, you know my take on RE. I don’t think you can RE truly modern stuff like the F-16/Su-27/30 or F-404 or AL-31.

If the chini could RE the F-16, they would do it and the PAF would have unlimited supply of their favorite F-Solah. But even the PRC can’t and they didn’t with the Su-27/30 either. Those are pure ToT. I’ve shown that in other threads.

The MiG-21/Tumansky 25 and F-5/J-85 are the last reverse engineerable technology combination IMO. The J-7E/PG and the Iranian Saqeah are the last examples of real indigenous clones. J-10 and J-11 are technology transfers from Israel and Russia respectively.

So being faithful to contracts is not necessarily wrong. It’s negotiations that prioritize (politically sensitive) local offsets and jobs over actual tech transfers that is wrong.

That said, why should we not use the HAL Su-30 MKI line and what we’ve learnt from operating that line to build our own variants? Why should HAL cry and moan that the last 30 MKIs will be up soon? Hell, why not use the production line and the ecosystem built around the MKI in a new project? We can call it a new name and say it is a new indigenous aircraft if the Russians piss and moan. I bet you they won’t if the first couple of hundred or so of this Hindi Flanker use Russian AL-31s.

chola
BRFite
Posts: 1737
Joined: 16 Dec 2002 12:31
Location: USA

Re: Kaveri & aero-engine discussion

Postby chola » 19 Oct 2017 23:58

Vivek K wrote:
NRao wrote:.... One can do only so much via RE. Flip side, there is no alternative to a local effort.

Also, there is a need to have a team that looks into disruptive techs. Beyond the effort to either complete the Kaveri or dup a F414. The two teams need to constantly hook up to ensure a contemporary engine, one that will be able to stand on its own on some platforms.

And form a base for future engines.

15-20 years IMHO. At least.

If Metallurgy is not a barrier, then RE can help you overcome design challenges. Also, how does it help to say 15-20 years and after the Kaveri experience, does it still take 15 years? Is Kaveri struggling for metallurgy or due to design?


You see the issues we have had with the MKI’s AL-31 and the MiG-29’s RD-33? You think the Russuans don’t have the design down pat after all these years? Brand new Russian engines can generate power just as well as their western counterparts. They just break down a lot more and a lot faster than western engines.

So that tells me it is material. We will not be able to beat the Russians with our first design so if THEY are having these problems . . .

My guess is it is material related. Design can be inferred by taking engines apart. We’ve done enough with the RD-33 (which in the Kaveri class) to know the design. But taking apart an engine gives you NOTHING about the alloys going into making the actual parts of that engine.

ramana
Forum Moderator
Posts: 48099
Joined: 01 Jan 1970 05:30

Re: Kaveri & aero-engine discussion

Postby ramana » 20 Oct 2017 05:40

Or all those long endurance drones.

Its the combustion through the hot stage.

Fact that Kaveri will have a French core tells you something.

Anyway whats the progress of the HAl jet engine project?

shiv
BRF Oldie
Posts: 33961
Joined: 01 Jan 1970 05:30
Location: Pindliyon ka Gooda

Re: Kaveri & aero-engine discussion

Postby shiv » 20 Oct 2017 07:34

The Kaveri AFAIK is a working engine. Please allow me a rude analogy. Hammering Kaveri is like complaining that a genetically engineered lab grown test tube penis is not working. It cannot work until it is attached to a human and tested to do its thing.

By now, in any engine manufacturing country it would have been mounted on a flying test bed at home and would have made hundreds of flights. It would then have been tested on a real fighter test bed. Running the engine for 10,000 hours in a test tube er shed is no use. The oldest jet engines and many newer ones were not reliable. But even if an engine can fly for 10 hours it is enough for a few tests. Fly 25 minute sorties and then take the engine apart to see how the parts are doing. We need to develop a mindset and an ecosystem for engines. We have not done that. But I am hoping that HALs engines will work. That is the next great hope.

We cannot remain stuck in Kaveri mode forever. We need to move on and create new engines of differing thrust specs for different application. One lab and one engine simply does not cut it.

BTW - why can't a well equipped engineering college produce a gas turbine engine?

ramana
Forum Moderator
Posts: 48099
Joined: 01 Jan 1970 05:30

Re: Kaveri & aero-engine discussion

Postby ramana » 20 Oct 2017 19:52

Shiv asked:

BTW - why can't a well equipped engineering college produce a gas turbine engine?


Same reason GTRE cant produce a GT engine.

The college has very good engineering but not technology.

Makin products needs in addition to engineering, technology. The nitty-gritty of what should be the tolerances on the part to ensure free running at high temperatures, what pressure for the fuel pumps to inject fuel into the high pressure section of the turbine to ensure continuous combustion. In college we were taught how to calculate the overall compression ratio and the what blade frequencies (the beauty of Dan Hertzog's variable thickness disc natural frequency calculations etc.) etc. but not the technical drawings to make the parts. The first cut of design based on these calcs is all that is taught. Then it has to be built and the dimensions adjusted for the engine design to run smoothly. This part is left for the industry which is non-existent.


One guy in Voltas interview demanded how I will tolerance a shaft with stepped diameters. I left one part with out dimensions to allow for float. And he wanted to know why? I told him and he gave big lecture about how colleges don't teach such skills.
But obviously I did no? Turns out he was a from the ranks engineer and had a chip against college graduates.

Any way all they were making were assembly of water coolers and didn't need my skills.

Zynda
BRFite
Posts: 1295
Joined: 07 Jan 2006 00:37
Location: J4

Re: Kaveri & aero-engine discussion

Postby Zynda » 20 Oct 2017 20:02

ramana wrote:One guy in Voltas interview demanded how I will tolerance a shaft with stepped diameters. I left one part with out dimensions to allow for float.


Is this the float you are referring to is the floating bearing centre dimension? As illustrated in this figure below?

Image

ramana
Forum Moderator
Posts: 48099
Joined: 01 Jan 1970 05:30

Re: Kaveri & aero-engine discussion

Postby ramana » 20 Oct 2017 20:22

yeah some thing like that. Its was so long ago.

Not germane to this thread and sorry for bringing it up.

chola
BRFite
Posts: 1737
Joined: 16 Dec 2002 12:31
Location: USA

Re: Kaveri & aero-engine discussion

Postby chola » 22 Oct 2017 17:22

While doing research on Kaveri and how other nations managed on aircraft engines, I realized that we, Japan and Cheen are the ones who had even tested a prototype turbofan outside the Big Three of US, EU (UK/France) and Russia.

So comparison with the Japonese and chinis (again) would be most relevant. Cheen more relevant to our situation than Japan since the Japanese are technically on par with the Big Three but are under an enforced pacifist regime by the Amreekis so their history is skewed.

The Japanese have produced high bypass turbofan engines for transport and civvy planes for decades but mostly not the low bypass types for fighters except a few for trainers. (Their F-2 was originally designed to have indigenous airframe and engine but US pressure turned it into a F-16 derivative and a F-110 engine.) That could change in the future as Abe is a nationalist and their stealth X-2 has the XF-5 3D thrust vectoring turbofan.

So not only are the Japanese on a vectoring turbofan(!), they were so experienced and confident that two of them powered the X-2’s first flight in April, 2016. Albeit it is twin engine with a margin of safety, still can you imagine plugging a Kaveri on the LCA now never mind its first flight!

So comparison with Japan is probably not very useful.

Brazil, with Embraer is an aircraft manufacturing giant in the third world. Ahead of us and Cheen as a builder of civilian aircraft. But they have never attempted a turbofan and have only recently developed turbojets mainly for their drones and cruise missiles.

I’ll write up Cheen later (maybe in the Chin mil thread.) But the surprising thing about their turbofan program is that it originates in the CMF56 civvy turbofan for the DC 8.

The fact we got the Kaveri to a test platform in Russia was a MASSIVE achievement restricted to a very select few. But failure was probably a foregone conclusion when attempting something this difficult without a foundation. Sort of a heroic tragedy that was fated.

VKumar
BRFite
Posts: 301
Joined: 15 Sep 1999 11:31
Location: Mumbai,India

Re: Kaveri & aero-engine discussion

Postby VKumar » 22 Oct 2017 19:01

Vivek K wrote:True. Need a new company to first develop a turbojet and a line of turboprops - these could also go into the HTT 40.

But why does India care so much for contract obligations - no one else does! Pakistan let the Chinese look inside the F-16, the Chinese REed the Mig-21, the SU-27, the Su-30. Why do we observe regulations that no one else does?

If our CFD staff are sitting around twiddling their thumbs, they should be tasked with modeling the aircraft in IAF inventory and study their aerodynamics and look for improvements. It is time for India to not play stupid anymore.


Sir, powers that can influence armed forces to ignore or even vilify indigenous products can influence the defence manufacturing set up NOT TO COPY OR REPRODUCE FOREIGN MAAL.


Return to “Military Issues & History Forum”

Who is online

Users browsing this forum: Aditya_V and 41 guests