Kaveri & Aero-Engine: News & Discussion

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Singha
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Re: Kaveri & aero-engine discussion

Post by Singha »

that would be a billion well spent imo if it truly delivers a product.
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Re: Kaveri & aero-engine discussion

Post by Prasad »

Kartik wrote:This news about Safran being very close to signing a deal with DRDO to develop the Kaveri-M-88 hybrid is apparently true. Got that confirmation from a French source. We'll find out soon enough as to what is being planned.
What have they been working on so far? If at all they have I mean.
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Re: Kaveri & aero-engine discussion

Post by Neela »

Can someone clarify what the m88 core means.
Does it mean turbine section, afterburning section as well HP compressor stages?

If it includes the compressor stages, there is little of our own R&D in it. FADEC will also be Snecmas as core fuel injection etc will be controlled through it.

That leaves only the fan & LP stages
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Re: Kaveri & aero-engine discussion

Post by Neshant »

Will wrote:If the French are investing 1 Bn of their own money think there is something bigger in the pipeline. Probably a joint development of an engine for the AMCA.
They are not really investing anything.
Rather offered their services at the rate of 1 billion to insert the core of their M88 into the kaveri as an offset for India purchasing the Rafales - which India accepted.

India is paying through its nose for what amounts to a largely foreign engine clothe in Indian fabric. i.e. M88-Kaveri

Its perhaps 1 step up from screw driver turning aka assembling foreign designed products and paying a huge bill to do so- which is the lowest cast profession around.

GOI is failing massively on promoting the development of a domestic aerospace R&D base.
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Re: Kaveri & aero-engine discussion

Post by Aditya_V »

I think this is a positive step, Unless GE 414 engines are goign to be manufactured in India will full tot because

1) If this engine will work , it gives designers an engine around which to build the LCA MK 2 and AMCA.

2) This also help us to understand better about Jet engines and Manufacture and keep the production lines going.

3) In such Assembly and manufacture we should be able to overhaul and maintain these engines within India.

So in war time these engines can be maintained in India for atleast 3 to 6 months, making them partly sanction proof.

The only thing I hope GOI is separately funding our own engine developments.
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Re: Kaveri & aero-engine discussion

Post by Vips »

Uncle Sam's next move will be crucial. They will have to offer something more substantive then the the French if they want to have direct/indirect control over new birds which will be with IAF for the next 50 years.
We should have involved greater number of players in the engine program to ensure some hot core TOT.
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Re: Kaveri & aero-engine discussion

Post by madhu »

guys, i am having lunch with Dr. K. Ramachandra, Former Director, GTRE on Friday. if you have any specific questions on kaveri engine just PM/post. will try to get it for you.
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Re: Kaveri & aero-engine discussion

Post by Rakesh »

Cain Marko wrote:
Rakesh wrote:Mithai and Champagne bottle waiting.... :)
Arrey saar jingoes been waiting for famous unobtanium mithai for so long....Ab champagne ke sapno pey latkaogey kya. You must've for sure been part of the MOD in a past life, saarey BR vasiyon ko latka Ke rakha Hai aur ab naye rfi (champagne) ki baat chala Rahe ho.... :D
:rotfl: :lol:
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Re: Kaveri & aero-engine discussion

Post by Rakesh »

madhu wrote:guys, i am having lunch with Dr. K. Ramachandra, Former Director, GTRE on Friday. if you have any specific questions on kaveri engine just PM/post. will try to get it for you.
Can you please ask Dr Ramachandra - if he is aware - on which of the following two has been adopted? Very insightful post by Ramana-ji.
ramana wrote:I think there are two options here.

1) Increase the M88 core diameter to match the Kaveri system. This means keep the rest of the (TCA) T/F+ Casing+ AB same.
- This option is risky as changing core to match the TCA could be tricky.
- However GTRE will learn the most from this option as they learn to resize the core.

2) Keep the M 88 core as it works and redo the TCA as GTRE knows how.
- Could be long drawn out process as three systems have to be developed: T/F+ Casing + AB And more costly from Indian side. Kind of defeats the offsets as India gets to spend twice.
- GTRE wont learn anything new as they already had developed the TCA. Redoing the TCA is not new technology.
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Re: Kaveri & aero-engine discussion

Post by JayS »

madhu wrote:guys, i am having lunch with Dr. K. Ramachandra, Former Director, GTRE on Friday. if you have any specific questions on kaveri engine just PM/post. will try to get it for you.
Thanks for the generous offer. There are many questions but if would be good to get some authoritative word on following two.
1. Has the Kabini core achieved design objectives..? And Dry thrust meeting the design goal..?
2. What are the gaps remaining still for Kaveri to reach finish line. As far as I figure out two main issues are there - one is flutter in Fan blades at certain flight regimes and second is sub-optimal functioning of A/B. Can you confirm if this is correct assessment or there's more to it..?
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Re: Kaveri & aero-engine discussion

Post by ramana »

And above all please invite him to join the forum. Would add a lot of value.
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Re: Kaveri & aero-engine discussion

Post by Rakesh »

Safran close to India combat jet engine deal: sources
https://in.reuters.com/article/safran-i ... NKCN1GB31E

France’s Safran (SAF.PA) is close to an agreement to supply a version of its M88 military jet engine for India’s Tejas light combat aircraft, two people close to the discussions said. The deal, if confirmed, could be finalised during a visit to India by French President Emmanuel Macron next month, they said, adding that negotiations could still be blown off course. Safran declined comment. French newspaper La Tribune, which first reported the possible deal, said the M88 would be offered as part of a revived version of India’s stalled Kaveri jet engine programme, which was initially linked to the Tejas. The Tejas fighter entered service in 2016, 33 years after it was approved as the country sought to build a modern fighter from scratch for an air force that was entirely dependent on foreign - mostly Soviet-origin - aircraft. But the single-engine plane has been dogged by production delays at state-run Hindustan Aeronautics and only a small number have so far entered the air force, currently powered by engines from General Electric.
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Re: Kaveri & aero-engine discussion

Post by Singha »

the euros may be more likely to share things given their funding situation and arms embargo on china the moneybags.
for GE, a billion here or there is a coin in piggy bank due to massive scale of massan orders.
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Re: Kaveri & aero-engine discussion

Post by ramana »

A Deshmukh
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Re: Kaveri & aero-engine discussion

Post by A Deshmukh »

Are they planning a M88-Kaveri engine for Tejas Mk1A? this will need a round of testing and re-certification. will delay the procurement of Mk1A.

IMHO, M88-Kaveri should be used for Tejas Mk2 or M1B or whatever, without delaying the 83 M1A procurement.
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Re: Kaveri & aero-engine discussion

Post by SaiK »

It would be an upthrusted version of M88. JMT
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Re: Kaveri & aero-engine discussion

Post by Yagnasri »

French are largely sanction proof deal. That should be one of the main considerations. Not fully as it used to be. Remember the ship deal they broke with Russia? They may allow us to export LCA more than Khan.
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Re: Kaveri & aero-engine discussion

Post by madhu »

JayS wrote: Has the Kabini core achieved design objectives..? And Dry thrust meeting the design goal..?
He told that he do not remember exact number for the thrust but it was close to what was needed. In fact it is too compact and he felt that GTRE has done a very good job on core engine.
JayS wrote:What are the gaps remaining still for Kaveri to reach finish line. As far as I figure out two main issues are there - one is flutter in Fan blades at certain flight regimes and second is sub-optimal functioning of A/B. Can you confirm if this is correct assessment or there's more to it..?
The major problems of flutter induced vibration of fan and initial compressor blades were fixed. In fact due to pattern factor combustor LP turbine blades were getting excitied to torsional mode. He told all these were fixed. The issue are meeting the dry thrust and thrust with A/B. currently with out A/B is still around 47 kN( ~8% short) and Full afterburner ~76 kN ( not sure) or so…
He told this can be achieved by pluged the leak and other small redesign to increase. He feels another 5% ( in short fall of current 8%) can be done with ease but reaching 100% thrust will be tough.
JayS wrote:What are the gaps remaining still for Kaveri to reach finish line...?
It has to be ground tested on actual flight: taxing , low altitude flight and high altitude flights to get qualification. He told India do not have region specific certification criteria. What is following is best from all certificates. So we have a tight requirements.
Rakesh wrote:Can you please ask Dr Ramachandra - if he is aware - on which of the following two has been adopted? Very insightful post by Ramana-ji
He told the issue was sorted back in 2000 itself that we will have Kaveri core and rest of it be re-designed. In fact all the people (GE/France/Russia) were ready to work with GTRE with Kaveri core and develop.
Ramana wrote:And above all please invite him to join the forum. Would add a lot of value
He is almost 70’s and is actively involved in teaching. Guiding few Phd’s.
Last edited by madhu on 28 Feb 2018 21:23, edited 1 time in total.
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Re: Kaveri & aero-engine discussion

Post by Rakesh »

A Deshmukh wrote:Are they planning a M88-Kaveri engine for Tejas Mk1A? this will need a round of testing and re-certification. will delay the procurement of Mk1A.

IMHO, M88-Kaveri should be used for Tejas Mk2 or M1B or whatever, without delaying the 83 M1A procurement.
Don't think along the lines - yet - of mating Kaveri with a specific Tejas variant.

Right now the goal is to test the engine, certify the engine and then begin production of the engine. That's it.

The F404 engine is there right now for Mk1 and Mk1A. Let them continue with that.
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Re: Kaveri & aero-engine discussion

Post by Rakesh »

SaiK wrote:It would be an upthrusted version of M88. JMT
I am thinking along the same lines as well. Safran's CEO has been talking about uprating the M88 for a while now. He believes the Rafale has gotten heavier over the years with the newer variants rolling out: F1 ---> F2 ---> F3 ---> F3R ----> F4. However Dassault was not biting, perhaps they did not want to invest the money in uprating the M88. Now with the Indian Rafale deal, Safran got a perfect opportunity to do just that. Regardless, it is a big benefit for India. These are the articles I read back in 2016 of Safran's CEO wanting to uprate the M88 turbofan...

Safran wants to boost M88's thrust to 20,000 lbs
http://alert5.com/2016/03/17/safran-wan ... 20000-lbs/

Safran Plans Engine Upgrade For Dassault Rafale Fighter Jet
http://www.defenseworld.net/news/15614/ ... pbFVtKWxMs

However, let us wait till what President Macron has to say on March 10th. But just like I said, I strongly believe they will follow the Turbomeca Shakti model, in which HAL is doing screwdrivergiri on the Ardiden 1H1 turboshaft for the Dhruv and Ardiden 1U turboshaft for the LUH.

I want them to test the Kaveri88 on the Rafale onlee. One engine bay M88 and another engine bay Kaveri88.

Next phase of testing to have both engine bays with Kaveri88. Once certification is complete, then license production can begin.

Have our own Rafales, Tejas and possibly MiG-29Ks with Kaveri88 turbofans.

Chai-Biscoot-Samosa Time :)
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Re: Kaveri & aero-engine discussion

Post by Rakesh »

Madhu: Thank you so much for the replies to all the queries, including mine. Very Happy.
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Re: Kaveri & aero-engine discussion

Post by ramana »

A Deshmukh wrote:Are they planning a M88-Kaveri engine for Tejas Mk1A? this will need a round of testing and re-certification. will delay the procurement of Mk1A.

IMHO, M88-Kaveri should be used for Tejas Mk2 or M1B or whatever, without delaying the 83 M1A procurement.
No. It will be for replacement engines after the F404 are end of life. So no jeopardizing Mk1A or even Mk2. However if GE balks then, expect in Mk2.
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Re: Kaveri & aero-engine discussion

Post by ramana »

Madhu, Thanks. So it's the Kabini core that's good and rest have to be rejigged.

Can we ask you questions once in a while for you to run it by him?
That way we have a way to get gnan like Ekalavya?
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Re: Kaveri & aero-engine discussion

Post by Rakesh »

Ramana-ji, can you please translate for this nanna mujahid whether it is scenario 1 or scenario 2 (in your post) that worked out.
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Re: Kaveri & aero-engine discussion

Post by JayS »

Rakesh wrote:Ramana-ji, can you please translate for this nanna mujahid whether it is scenario 1 or scenario 2 (in your post) that worked out.
Neither, if I understand correctly.
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Re: Kaveri & aero-engine discussion

Post by JayS »

madhu wrote:
JayS wrote: Has the Kabini core achieved design objectives..? And Dry thrust meeting the design goal..?
He told that he do not remember exact number for the thrust but it was close to what was needed. In fact it is too compact and he felt that GTRE has done a very good job on core engine.
JayS wrote:What are the gaps remaining still for Kaveri to reach finish line. As far as I figure out two main issues are there - one is flutter in Fan blades at certain flight regimes and second is sub-optimal functioning of A/B. Can you confirm if this is correct assessment or there's more to it..?
The major problems of flutter induced vibration of fan and initial compressor blades were fixed. In fact due to pattern factor combustor LP turbine blades were getting excitied to torsional mode. He told all these were fixed. The issue are meeting the dry thrust and thrust with A/B. currently with out A/B is still around 47 kN( ~8% short) and Full afterburner ~76 kN ( not sure) or so…
He told this can be achieved by pluged the leak and other small redesign to increase. He feels another 5% ( in short fall of current 8%) can be done with ease but reaching 100% thrust will be tough.
JayS wrote:What are the gaps remaining still for Kaveri to reach finish line...?
It has to be ground tested on actual flight: taxing , low altitude flight and high altitude flights to get qualification. He told India do not have region specific certification criteria. What is following is best from all certificates. So we have a tight requirements.
Rakesh wrote:Can you please ask Dr Ramachandra - if he is aware - on which of the following two has been adopted? Very insightful post by Ramana-ji
He told the issue was sorted back in 2000 itself that we will have Kaveri core and rest of it be re-designed. In fact all the people (GE/France/Russia) were ready to work with GTRE with Kaveri core and develop.
Ramana wrote:And above all please invite him to join the forum. Would add a lot of value
He is almost 70’s and is actively involved in teaching. Guiding few Phd’s.
Hajar pranam for confirmations. So the info I posted previously on the status of Kaveri from what I gathered from AI-17 was bang on the bucks.

The numbers I had in my mind were 49kN and 72kN. A country like China would have ran with the fabulous success that GTRE has achieved against all the odds. And here we keep harping endlessly and go around with begging bowl for alms still.

I think your post should be copied to the Kaveri sticky thread. I will do so.
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Re: Kaveri & aero-engine discussion

Post by Indranil »

Madhu, thanks a lot. What an example of a good post and poster. Nuggets of gold with no crap.

If there is ANY way that we could involve him at this forum, I am ready to work with you on this. Please PM me.
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Re: Kaveri & aero-engine discussion

Post by ramana »

JayS wrote:
Rakesh wrote:Ramana-ji, can you please translate for this nanna mujahid whether it is scenario 1 or scenario 2 (in your post) that worked out.
Neither, if I understand correctly.



SAFRAN is planning a new Engine with the M-88 core and the TCA periphery will be designed around it.

GTRE can be happy they got close to finish line but not across it.
The retired director has said achieving 100% of the goals is not possible.

They did this with under $350 M stretched over so many years.


By redesigning the TCA they can fix the vibration in fan, the chamber will fit round the core and the after burner will take care of developing the thrust there.

Recall the A/B is used for take off and to escape dog fight. So is used crucial 20% of life say but very crucial.

If I had my say I would have had the LCA weight gains and used the Kaveri without calumny.

Would have funded GTRE for Kaveri 2 for the Mk2 and continued.

But officialdom has the luxury to give $1.2B to France and get it back as investment in JV.

But not one paisa to GTRE.

The Scientific Adviser to RM should have been more forceful about funding GTRE. They did fantastic job with the meager allocation.
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Re: Kaveri & aero-engine discussion

Post by JayS »

I am quoting my old posts from AI-17 time in current context.

viewtopic.php?f=3&t=3351&start=3040#p2119110
JayS wrote:
I am told 54kN/81kN thrust is achieved. I specifically asked for wet thrust against since we know there was shortfall there. But GTRE folks were insisting that they have achieved 81kN now. Both the compressor flutter and screech issues are resolved now, if you believe them.

SCB is GTRE+DMRL project. SCB with 2nd Gen alloys process is matured tech now, Industrialization of the process is remaining. Apart from making raw blades two more key things lacking are final machining of the SCB's and TBC. MIDHANI is working on this. And they are confident they can do it in 2-3yrs. Right now the blades are to be sent abroad for one or both of these two processes anyway, which is not desirable.

If you notice, Kaveri is running with max 1700K TET value. Currently its not using any SCBs, only DS blades, as per GTRE folks. There is a gap of ~200K here from the state-of-the-art.
viewtopic.php?f=3&t=3351&start=3040#p2119152
JayS wrote:
Its know from public sources those two problems where uncovered. Interestingly a guy from GTRE manning the stall told me they are paying Russians just so they wouldn't share the mods GTRE did to remove those issues. Now how much one wants to buy into this is up to oneself. :)

Snecma claims 1850K TET for M88. So just by porting that HPT tech they can boost TET by 150K..!!

But my guess is they will not do much technical changes in the engine itself, if what GTRE says is true. The said 25% remaining work to make it flightworthy is majority flight testing only without much HW changes. Even if we get flight testing know-how and facilities set up with Snecma's help that itself would be significant for us. We already know Kabini core is working well. It was only the issue with LP system and AB. If those two things are solved then there's nothing really remained in Kaveri to do. Just fly it and certify. Other changes can be done in next iteration.

Also, Kaveri Marine project is not going anywhere since Navy changed the requirements. Now they want next gen specs, I am told.
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Re: Kaveri & aero-engine discussion

Post by Rakesh »

Thank you JayS and Ramana-ji. Much appreciated.
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Re: Kaveri & aero-engine discussion

Post by hanumadu »

madhu wrote:
JayS wrote:What are the gaps remaining still for Kaveri to reach finish line. As far as I figure out two main issues are there - one is flutter in Fan blades at certain flight regimes and second is sub-optimal functioning of A/B. Can you confirm if this is correct assessment or there's more to it..?
The major problems of flutter induced vibration of fan and initial compressor blades were fixed. In fact due to pattern factor combustor LP turbine blades were getting excitied to torsional mode. He told all these were fixed. The issue are meeting the dry thrust and thrust with A/B. currently with out A/B is still around 47 kN( ~8% short) and Full afterburner ~76 kN ( not sure) or so…
He told this can be achieved by pluged the leak and other small redesign to increase. He feels another 5% ( in short fall of current 8%) can be done with ease but reaching 100% thrust will be tough.
The dry thrust and wet thrust figures are from 5 years ago or may be more. The screech and vibrations are fixed is good news.

Indian establishment does not want to let out the state of various projects especially the strategic ones.
The vibrations and AB problems were fixed in 2000 but they were given wide publicity only recently with defence journalists reporting they are yet to be fixed.

Another example is Tejas Mk2 status. All news was of how not work is being done on it and it is shelved but Saurav Jha recently tweeted much work was done on it and a prototype can be developed in 2-3 years if funded.

I take all news on our strategic programs as something that the establishment wants us to know rather than what the actual state is.
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Re: Kaveri & aero-engine discussion

Post by madhu »

ramana wrote:Madhu, Thanks. So it's the Kabini core that's good and rest have to be rejigged.
Can we ask you questions once in a while for you to run it by him?
That way we have a way to get gnan like Ekalavya?
sorry ramman. its just that i was in a course learning about design and analysis of Jet engines where he had come to lecture i happened to meet him.
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Re: Kaveri & aero-engine discussion

Post by madhu »

maitya wrote:Ok, so here it is ... a simplistic (yes, I must admit almost embarrassingly simplistic) side-by-side comparison of this so-called Kaver-with-M88-core, original Kaveri and “paper-injin” called “Improved Kaveri”.
(and no I can’t use Ganga, as it is copyrighted by Vinaji).

Image
i see that you have done calculations based on static thermodynamic points. i have seen performance engineer doing this based on stagnation points. what difference will it make?
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Re: Kaveri & aero-engine discussion

Post by Avarachan »

JayS wrote:I am quoting my old posts from AI-17 time in current context.

viewtopic.php?f=3&t=3351&start=3040#p2119110
JayS wrote:
I am told 54kN/81kN thrust is achieved. I specifically asked for wet thrust against since we know there was shortfall there. But GTRE folks were insisting that they have achieved 81kN now. Both the compressor flutter and screech issues are resolved now, if you believe them.

SCB is GTRE+DMRL project. SCB with 2nd Gen alloys process is matured tech now, Industrialization of the process is remaining. Apart from making raw blades two more key things lacking are final machining of the SCB's and TBC. MIDHANI is working on this. And they are confident they can do it in 2-3yrs. Right now the blades are to be sent abroad for one or both of these two processes anyway, which is not desirable.

If you notice, Kaveri is running with max 1700K TET value. Currently its not using any SCBs, only DS blades, as per GTRE folks. There is a gap of ~200K here from the state-of-the-art.
viewtopic.php?f=3&t=3351&start=3040#p2119152
JayS wrote:
Its know from public sources those two problems where uncovered. Interestingly a guy from GTRE manning the stall told me they are paying Russians just so they wouldn't share the mods GTRE did to remove those issues. Now how much one wants to buy into this is up to oneself. :)

Snecma claims 1850K TET for M88. So just by porting that HPT tech they can boost TET by 150K..!!

But my guess is they will not do much technical changes in the engine itself, if what GTRE says is true. The said 25% remaining work to make it flightworthy is majority flight testing only without much HW changes. Even if we get flight testing know-how and facilities set up with Snecma's help that itself would be significant for us. We already know Kabini core is working well. It was only the issue with LP system and AB. If those two things are solved then there's nothing really remained in Kaveri to do. Just fly it and certify. Other changes can be done in next iteration.

Also, Kaveri Marine project is not going anywhere since Navy changed the requirements. Now they want next gen specs, I am told.
JayS (or some other guru), could you write a brief article on the background and current status of the Kaveri project? I'm sure there will be lots of nonsense published trashing GTRE ("failure lab," etc.) over the next few weeks. It would be nice if BRF could publish a counter.

Saurav Jha, whom I respect, published an article on the current status in April 2017.
http://www.delhidefencereview.com/2017/ ... et-engine/
But, if your sources are correct, his article is not completely accurate.
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Re: Kaveri & aero-engine discussion

Post by madhu »

Avarachan wrote:
JayS wrote:I am quoting my old posts from AI-17 time in current context.

viewtopic.php?f=3&t=3351&start=3040#p2119110


viewtopic.php?f=3&t=3351&start=3040#p2119152
JayS (or some other guru), could you write a brief article on the background and current status of the Kaveri project? I'm sure there will be lots of nonsense published trashing GTRE ("failure lab," etc.) over the next few weeks. It would be nice if BRF could publish a counter.

Saurav Jha, whom I respect, published an article on the current status in April 2017.
http://www.delhidefencereview.com/2017/ ... et-engine/
But, if your sources are correct, his article is not completely accurate.
Reheat oscillations is still a problem.
JayS
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Re: Kaveri & aero-engine discussion

Post by JayS »

Avarachan wrote:
JayS wrote:I am quoting my old posts from AI-17 time in current context.

viewtopic.php?f=3&t=3351&start=3040#p2119110


viewtopic.php?f=3&t=3351&start=3040#p2119152
JayS (or some other guru), could you write a brief article on the background and current status of the Kaveri project? I'm sure there will be lots of nonsense published trashing GTRE ("failure lab," etc.) over the next few weeks. It would be nice if BRF could publish a counter.

Saurav Jha, whom I respect, published an article on the current status in April 2017.
http://www.delhidefencereview.com/2017/ ... et-engine/
But, if your sources are correct, his article is not completely accurate.
Unfortunately I do not have time at hand currently, but I can summarize things in one post sometime soon.
JayS
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Re: Kaveri & aero-engine discussion

Post by JayS »

madhu wrote:
Avarachan wrote:
JayS (or some other guru), could you write a brief article on the background and current status of the Kaveri project? I'm sure there will be lots of nonsense published trashing GTRE ("failure lab," etc.) over the next few weeks. It would be nice if BRF could publish a counter.

Saurav Jha, whom I respect, published an article on the current status in April 2017.
http://www.delhidefencereview.com/2017/ ... et-engine/
But, if your sources are correct, his article is not completely accurate.
Reheat oscillations is still a problem.
Madhu, just to avoid misinterpretation, please confirm whether following points are correct or not, based on your recent interaction. Just a final check for me to store the broad points in my mind as correct. I will soon forget details.

1. The short fall in achieved dry thrust by Kaveri is in single digit percentage (8% as you mentioned, I have seen 3-4% in some other place, but still single digit).
2. The demonstrated wet thrust is somewhere between 72-76kN, various values I have seen so far.

Though GTRE claimed in AI-17 they achieved 52kN54kN/81kN we do not have independent verification so far. So lets keep it on hold.

3. One key issue with LPC was blade flutter which is resolved now.
4. LPT blade issue which I was not aware of previously is also resolved.
5. Issue with A/B clearly still persists. Reheat oscillations remains for A/B. Issue of screech was resolved as per GTRE's claim in AI-17, but again we lack verification.
6. The shortfall in Dry thrust can be bridged by some more work to some extent, but not fully.
7. The shortfall in Wet thrust is critically hampered by A/B performance and is unlikely to go away without significant improvement on A/B.
8. The way forward has always been "Kaveri core + modification of LP/A-B system with the help of foreign OEM" and that is still going to be the way forward. IOW, no core borrowing from any other engine.
9. French help is to bridge the gap mentioned in points 6 and 7 and help in flight testing.
JayS
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Re: Kaveri & aero-engine discussion

Post by JayS »

hanumadu wrote:
madhu wrote:
The major problems of flutter induced vibration of fan and initial compressor blades were fixed. In fact due to pattern factor combustor LP turbine blades were getting excitied to torsional mode. He told all these were fixed. The issue are meeting the dry thrust and thrust with A/B. currently with out A/B is still around 47 kN( ~8% short) and Full afterburner ~76 kN ( not sure) or so…
He told this can be achieved by pluged the leak and other small redesign to increase. He feels another 5% ( in short fall of current 8%) can be done with ease but reaching 100% thrust will be tough.
The dry thrust and wet thrust figures are from 5 years ago or may be more. The screech and vibrations are fixed is good news.

Indian establishment does not want to let out the state of various projects especially the strategic ones.
The vibrations and AB problems were fixed in 2000 but they were given wide publicity only recently with defence journalists reporting they are yet to be fixed.

Another example is Tejas Mk2 status. All news was of how not work is being done on it and it is shelved but Saurav Jha recently tweeted much work was done on it and a prototype can be developed in 2-3 years if funded.

I take all news on our strategic programs as something that the establishment wants us to know rather than what the actual state is.
I think you misunderstood, that the problems were fixed in 2000. They were not. Some of these problems were only uncovered in flight testing done in Russian much later (was it 2012..?).
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Re: Kaveri & aero-engine discussion

Post by Avarachan »

JayS wrote:Though GTRE claimed in AI-17 they achieved 52kN/81kN we do not have independent verification so far. So lets keep it on hold.
JayS, is this a typo? In your original post about AI-17, you said that GTRE claimed *54*/81.

If it was a typo, would you mind correcting your post? I greatly appreciate your efforts, by the way.
JayS
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Re: Kaveri & aero-engine discussion

Post by JayS »

Avarachan wrote:
JayS wrote:Though GTRE claimed in AI-17 they achieved 52kN/81kN we do not have independent verification so far. So lets keep it on hold.
JayS, is this a typo? In your original post about AI-17, you said that GTRE claimed *54*/81.

If it was a typo, would you mind correcting your post? I greatly appreciate your efforts, by the way.
Done. There are multiple numbers from 47-54 that I have come across over the time. Its easy for things to get mishmashed in my head. Likewise for wet thrust.
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