Kaveri & Aero-Engine: News & Discussion

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JayS
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Re: Kaveri & aero-engine discussion

Post by JayS »

Rishi Verma wrote:
JayS wrote:
Still waiting for answer...kindly enlighten us please.
You already know then why ask. One that was tested in Russia I call k-1. One that "may" get "improved" with French help, one that "may" get production ready, one that "may" find design win with AMCA I call K-2.

My point was when and if the K-2 materializes then it won't be necessary to test it on a foreign land on a foreign aircraft.
I don't know. I was hoping you would tell me, why the test data from "K-1" is not useful for "K-2". And to justify this statement, I hope you would tell us what exactly are the changes from K-1 to K-2 which make the test data from K-1 redundant.

I forgot to ask this to GTRE folks in AI-2017. So if you could tell me I would be grateful. Unless one knew what exactly Snecma would tinker with in K-1, how would one can say with confidence that the existing test data won't not useful anymore. I am looking forward, since you seems to know exact answers to what I seek. Humble request wonly.
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Re: Kaveri & aero-engine discussion

Post by JayS »

https://twitter.com/delhidefence/status ... 3096198144
Here's a picture of the MANIK small turbofan engine suitable fro cruise missile applications on a GTRE test-bed. Courtesy @DRDO_India
Image

I am told in AI-2017 by a GTRE guy when I asked if its the same engine as Laghushakti or something different - This engine "Small Turbofan Engine" was first dubbed as "Laghushakti". But later they changed the name to Manik in the honour of Dr K Tamilmani. Dunno if its true or not.
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Re: Kaveri & aero-engine discussion

Post by Rishi Verma »

JayS wrote:
Rishi Verma wrote:
You already know then why ask. One that was tested in Russia I call k-1. One that "may" get "improved" with French help, one that "may" get production ready, one that "may" find design win with AMCA I call K-2.

My point was when and if the K-2 materializes then it won't be necessary to test it on a foreign land on a foreign aircraft.
I don't know. I was hoping you would tell me, why the test data from "K-1" is not useful for "K-2". And to justify this statement, I hope you would tell us what exactly are the changes from K-1 to K-2 which make the test data from K-1 redundant.

I forgot to ask this to GTRE folks in AI-2017. So if you could tell me I would be grateful. Unless one knew what exactly Snecma would tinker with in K-1, how would one can say with confidence that the existing test data won't not useful anymore. I am looking forward, since you seems to know exact answers to what I seek. Humble request wonly.
Since you requested so humbly:

The test data is on a pendrive at Koramangala ram mandir near a paanwala shop in an encrypted PDF format. Please go there on Saturday with a coconut in your right hand and recite Hanuman Chalisa 108 times. The priest will give you the pen drive. If the priest breaks the coconut that means you didn't convince him and you should leave the premises asap.
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Re: Kaveri & aero-engine discussion

Post by Karan M »

Why don't you answer his query.
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Re: Kaveri & aero-engine discussion

Post by Cybaru »

Because its easier to hint/claim to be inside person/armed forces and keep that gray zone going to create/distinguish onself from other posters and hog the limelight.
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Re: Kaveri & aero-engine discussion

Post by Rakesh »

egxactly! :D bakwas kar raha hai!!
JayS
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Re: Kaveri & aero-engine discussion

Post by JayS »

Rishi Verma wrote:
JayS wrote:
I don't know. I was hoping you would tell me, why the test data from "K-1" is not useful for "K-2". And to justify this statement, I hope you would tell us what exactly are the changes from K-1 to K-2 which make the test data from K-1 redundant.

I forgot to ask this to GTRE folks in AI-2017. So if you could tell me I would be grateful. Unless one knew what exactly Snecma would tinker with in K-1, how would one can say with confidence that the existing test data won't not useful anymore. I am looking forward, since you seems to know exact answers to what I seek. Humble request wonly.
Since you requested so humbly:

The test data is on a pendrive at Koramangala ram mandir near a paanwala shop in an encrypted PDF format. Please go there on Saturday with a coconut in your right hand and recite Hanuman Chalisa 108 times. The priest will give you the pen drive. If the priest breaks the coconut that means you didn't convince him and you should leave the premises asap.
If only I knew Hanuman Chalisa or Ram Raksha. Alas..! But you seem to know all that evil yindoo stuff and must have got the pendrive by convincing the priest already (or you are the priest himself for all I know). So please be kind and let us know what you know (you said you know what you are talking about, didn't you..??) from that pendrive about K-1 and K-2. What is the difference between the two exactly which renders test data of K-1 so useless.
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Re: Kaveri & aero-engine discussion

Post by ramana »

My take.

Kaveri -!(the one that was tested in Russia) has noise at high rpm per DRDO chief Dr. Christopher.
To me this indicates turbine blade vibrations at high speed.
This means a blade stiffness issue.
You can either increase stiffness or reduce mass to get above the resonant frequency.

All this would need new test data.
So K-1 test data is interesting but not wholly germane to the K-2 after blade fix.

Anyway Dr. Christopher is confident it will be solved in a couple of years and will fly in an LCA.
He must have good basis for his confidence.
We have waited for so long and a wait of two more years wont affect our sanguinity.
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Re: Kaveri & aero-engine discussion

Post by NRao »

Anyway Dr. Christopher is confident it will be solved in a couple of years
So, why is France spending $1 billion - as offset for the Rafale deal?

And, are these two different/separate efforts? IF they are then both expect to have an engine that can be matted with the LCA?
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Re: Kaveri & aero-engine discussion

Post by JayS »

ramana wrote:My take.

Kaveri -!(the one that was tested in Russia) has noise at high rpm per DRDO chief Dr. Christopher.
To me this indicates turbine blade vibrations at high speed.
This means a blade stiffness issue.
You can either increase stiffness or reduce mass to get above the resonant frequency.

All this would need new test data.
So K-1 test data is interesting but not wholly germane to the K-2 after blade fix.

Anyway Dr. Christopher is confident it will be solved in a couple of years and will fly in an LCA.
He must have good basis for his confidence.
We have waited for so long and a wait of two more years wont affect our sanguinity.
Flutter in the booster stages (low pressure compressor). It happens only on certain points - at altitudes (my guess) and at high power op points (Dr Christopher). I am told GTRE resolved this issue already. They claimed they can fly it in LCA without help from Snecma. Take this one FWIW though.

Here is what we know already. Kabini core works well, as expected. How we can conclude this?? Kaveri has achieved targeted dry trust. There has been no dispute on this, reported anywhere that I have seen. UCAV program was linked to Kabini since quite a few years. They would not have done it without good confidence over Kabini's performance. Also Kaveri performed rather well in Marine avatar KGMT. This also indicates that the issue with flutter is at higher altitude point (amd thus it was uncovered only during flight testing in Russia. If only we atleast had our own High altitude test facility this problem could have been seen much earlier). The shortfall in wet thrust was due to AB performance. It has screech issue as well. (Now GTRE claim they have overcome this issue as well). From all the info I have seen, the problems are/were only for the LPC and AB.

Adding to this, French reviewed Kaveri and concluded about 20% work is remaining to make it flight-worthy. The ground tests, high speed taxi tests and actual flight tests itself is a huge task and I suspect it constitutes major portion on this 20% remaining tasks. Connecting the dots, I think, there is not much to be rectified in Kaveri. All measure issues must have been taken care of already. If there was any issue with the Kabini or major redesign on LPC/AB was needed, there is no way any one in the work can make Kaveri flight worthy in 2years. And there is no question of replacing Kaveri core with M88 core, since you can't just take one core and stick it to another engine's LP system without good 4-5yrs of work on it. I initially thought Scecma might do this but after some pondering and adding 2+2, I came to conclusion that there seems to be no reason why Kabini be replaced at all.

Even if we choose not to believe GTRE's claim that the design thrust for dry as well as wet conditions has been achieved already, still from the estimations/timelines/budgets given by Snecma, there seems to be no major technical issue to be resolved. Its mainly to add finishing touches, plucking some low hanging fruits and complete the rest of the test program.

JMT.

BTW another tidbit for jingos - currently Kaveri's stall margin is 19-20% as against design target of 22% while GTRE wants to achieve 25%. This is one thing yet to be achieved, they said in AeroIndia.
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Re: Kaveri & aero-engine discussion

Post by Indranil »

Rakesh wrote:egxactly! :D bakwas kar raha hai!!
Cybaru wrote:Because its easier to hint/claim to be inside person/armed forces and keep that gray zone going to create/distinguish onself from other posters and hog the limelight.
There is no need for this.
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Re: Kaveri & aero-engine discussion

Post by Rakesh »

Sorry Saar. No more.
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Re: Kaveri & aero-engine discussion

Post by Cybaru »

Fair enough Indranil, but please do call out posters who hint about some connection or inside knowledge to create a sense of authenticity where really none exists. I think we on BR treat almost everyone civilly so there is no need to do that on their part.
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Re: Kaveri & aero-engine discussion

Post by Neela »

Indranil
You had posted a table in blue font with Kaveri engines K5..K9 with details about the engine run times.
Forum search engine wouldn't let me search anything with less than 3 characters.
Im trying to see if info collected at AeroIndia2017 is newer than the table you posted.
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Re: Kaveri & aero-engine discussion

Post by ramana »

JayS, The search for realizing Kaveri is like Sagara's sons quest to realize the other great river Ganga. So many careers ended in the quest.

Now looks like Bhagirathi is about to emerge.
Lets hope Dr. Christopher is right and wish the team well.

Lesson don't name projects after Rivers!!!!
In IITM, the buses were named after mountains and hostels after rivers.
Go figure.
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Re: Kaveri & aero-engine discussion

Post by disha »

^^ So that buses arrive on time and hostels do not move away ...
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Re: Kaveri & aero-engine discussion

Post by shiv »

JayS wrote:BTW another tidbit for jingos - currently Kaveri's stall margin is 19-20% as against design target of 22% while GTRE wants to achieve 25%. This is one thing yet to be achieved, they said in AeroIndia.
What eej stall margin?
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Re: Kaveri & aero-engine discussion

Post by nachiket »

shiv wrote:
JayS wrote:BTW another tidbit for jingos - currently Kaveri's stall margin is 19-20% as against design target of 22% while GTRE wants to achieve 25%. This is one thing yet to be achieved, they said in AeroIndia.
What eej stall margin?
From wiki aunty:
A compressor will only pump air in a stable manner up to a certain pressure ratio. Beyond this value the flow will break down and become unstable. This occurs at what is known as the surge line on a compressor map. The complete engine is designed to keep the compressor operating a small distance below the surge pressure ratio on what is known as the operating line on a compressor map. The distance between the 2 lines is known as the surge margin on a compressor map. Various things can occur during the operation of the engine to lower the surge pressure ratio or raise the operating pressure ratio. When the 2 coincide there is no longer any surge margin and a compressor stage can stall or the complete compressor can surge as explained in preceding sections.
Last line is what happened in Fl.Lt. Nachiketa's Mig-27 due to gun-gas ingestion leading to engine flameout I believe.
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Re: Kaveri & aero-engine discussion

Post by JayS »

shiv wrote:
JayS wrote:BTW another tidbit for jingos - currently Kaveri's stall margin is 19-20% as against design target of 22% while GTRE wants to achieve 25%. This is one thing yet to be achieved, they said in AeroIndia.
What eej stall margin?
To add to Nachiket's post above, higher the stall margin, more the freedom you have throwing around your fighter without having to worry about stalling the engine at awkward angles when the engine is starving of incoming air.
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Re: Kaveri & aero-engine discussion

Post by Indranil »

^^^ learned something new. Thank you boys.
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Re: Kaveri & aero-engine discussion

Post by Neela »

Are these possible events that can influence surge margin?
Air pockets/High AoA/a bird hit ?

And design of intakes, fan , LP and HP compressor all influence the surge margin?
How the hell do they test the engine for all these conditions. It must be one mid boggling test envelope.
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Re: Kaveri & aero-engine discussion

Post by nachiket »

Neela wrote: And design of intakes, fan , LP and HP compressor all influence the surge margin?
How the hell do they test the engine for all these conditions. It must be one mid boggling test envelope.
Of course. That is why there are so few modern jet engine manufacturers in the world and why the technology and the test data is so zealously guarded. And why claims of ToT from Snecma etc. sound like a joke.

Also goes to show how important it is for GTRE to have all required test facilities in house, like some posters mentioned earlier.
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Re: Kaveri & aero-engine discussion

Post by srin »

JayS wrote:
Adding to this, French reviewed Kaveri and concluded about 20% work is remaining to make it flight-worthy. The ground tests, high speed taxi tests and actual flight tests itself is a huge task and I suspect it constitutes major portion on this 20% remaining tasks. Connecting the dots, I think, there is not much to be rectified in Kaveri. All measure issues must have been taken care of already. If there was any issue with the Kabini or major redesign on LPC/AB was needed, there is no way any one in the work can make Kaveri flight worthy in 2years. And there is no question of replacing Kaveri core with M88 core, since you can't just take one core and stick it to another engine's LP system without good 4-5yrs of work on it. I initially thought Scecma might do this but after some pondering and adding 2+2, I came to conclusion that there seems to be no reason why Kabini be replaced at all.
If you watch the Aero India press conference with MP, he said something to the effect of it will be based on M-83 (I presume he meant M-88). Since I don't understand anything about engines, I'm not too sure which technologies and to which part of the engine that French will contribute
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Re: Kaveri & aero-engine discussion

Post by shiv »

Please pardon my posting this video here. It is a (very good and well explained) jet engine primer and might be the best way for people to get familiar with issues
https://youtu.be/n1QEj09Pe6k
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Re: Kaveri & aero-engine discussion

Post by Cybaru »

Thanks Shiv! That was a wonderful primer on engines. The last line although not relevant for this thread was very insightful as well "The barrier to travel for most people is cost and not speed! Time is the enemy of privileged few and cost the enemy of the masses!"
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Re: Kaveri & aero-engine discussion

Post by JayS »

shiv wrote:Please pardon my posting this video here. It is a (very good and well explained) jet engine primer and might be the best way for people to get familiar with issues
https://youtu.be/n1QEj09Pe6k
Nice video, but take the technical info with a pinch of salt.
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Re: Kaveri & aero-engine discussion

Post by shiv »

JayS wrote: Nice video, but take the technical info with a pinch of salt.
In the video - European stuff is "not so good" and the CFM 56 - one of the most widely used and reliable engines ever is given second rank and consolation prize.
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Re: Kaveri & aero-engine discussion

Post by Neshant »

How about a Bombardier or Embrarer aircraft as an engine test bed.
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Re: Kaveri & aero-engine discussion

Post by Neela »

IDRW has a screengrab video of HTFE at full thrust.
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Re: Kaveri & aero-engine discussion

Post by abhijitm »

Why not contact Boeing to hire their testbed?
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Re: Kaveri & aero-engine discussion

Post by JayS »

BTW has anyone posted this, that HTSE-1200 design is completed, prototype is in making and HAL is targeting to fire it up by end of 2017.
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Re: Kaveri & aero-engine discussion

Post by NRao »

JayS wrote:BTW has anyone posted this, that HTSE-1200 design is completed, prototype is in making and HAL is targeting to fire it up by end of 2017.
Does the number have a meaning? And if so what? Perhaps the thrust, but in what units?
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Re: Kaveri & aero-engine discussion

Post by JayS »

NRao wrote:
JayS wrote:BTW has anyone posted this, that HTSE-1200 design is completed, prototype is in making and HAL is targeting to fire it up by end of 2017.
Does the number have a meaning? And if so what? Perhaps the thrust, but in what units?
1200 kW power.
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Re: Kaveri & aero-engine discussion

Post by Rakesh »

An article from Feb 2017...

India’s Ghatak Stealth UCAV Moves Forward, Likely With Dassault
http://www.livefistdefence.com/2017/02/ ... rward.html
A total of approximately $450 million will be spent from the Indian side in bringing the Kaveri engine to satisfactory operating standards through a tech partnership with France’s Snecma as part of committed offsets from the Indian Rafale contract. Top sources confirm that the technology infusion from France intends to make the Kaveri a standard engine for the LCA Tejas, to assist its modification for the Ghatak and for twin-configuration on the AMCA.
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Re: Kaveri & aero-engine discussion

Post by Cybaru »

We could repurpose one of the retired tu 142 for engine testing. The missile pylons that carry ashm are strong enough to take on an engine. Possible???
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Re: Kaveri & aero-engine discussion

Post by shiv »

Rakesh wrote:An article from Feb 2017...

India’s Ghatak Stealth UCAV Moves Forward, Likely With Dassault
http://www.livefistdefence.com/2017/02/ ... rward.html
A total of approximately $450 million will be spent from the Indian side in bringing the Kaveri engine to satisfactory operating standards through a tech partnership with France’s Snecma as part of committed offsets from the Indian Rafale contract. Top sources confirm that the technology infusion from France intends to make the Kaveri a standard engine for the LCA Tejas, to assist its modification for the Ghatak and for twin-configuration on the AMCA.
I am suspicious of any article that claims that nation x or company y will magically make Kaveri OK
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Re: Kaveri & aero-engine discussion

Post by srai »

^^^

Kaveri is mostly ready. It needs that "last-mile" help from an experience partner to get it over the hump.
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Re: Kaveri & aero-engine discussion

Post by devesh »

An appropriate question: what incentive does France have to help India overcome US engine monopoly of GE?

Secondly, US and France are treaty partners and firmly within the Atlanticist alliance. Why would one of them help break the monopoly of the other in military tech to a 3rd party which continues to buy from them both in billions of $$?
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Re: Kaveri & aero-engine discussion

Post by NRao »

devesh wrote:An appropriate question: what incentive does France have to help India overcome US engine monopoly of GE?

Secondly, US and France are treaty partners and firmly within the Atlanticist alliance. Why would one of them help break the monopoly of the other in military tech to a 3rd party which continues to buy from them both in billions of $$?
Neither is doing anything beyond getting AN engine to work under very small parameters (compared to what each of them can do). After both these exercises India will be where they are today - give and take some - with two workable engines. Would India be able to design and produce the next gen engine? I do not think so. Both will make sure that the status quo is maintained.

Note that all France has promised is a kaveri engine to mate with the LCA. They have been saying that since 2008-9.

The US wanted a Brahmos type of a deal. India proposed an engine.

Both are one shot deals. Great within themselves. Nothing more.
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Re: Kaveri & aero-engine discussion

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