Kaveri & Aero-Engine: News & Discussion

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Indranil
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Re: Kaveri & Aero-Engine: News & Discussion

Post by Indranil »

Certainly, it is for new Kaveri.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by astal »

Regarding the importance of sanctions.The desire to import is a sign of lack of patience, confidence and long term vision (if there is no explicit corruption). The foreign exporter/country has a strong interest in limiting and controlling the amount of technology provided and its application. This has happened with countless imported systems.

When specific weapons and technology are sanctioned, it is easier to inspire Indian workers, there are far lower chances of corruption and favors. We get the best of what is possible in the platform. Tejas is evolving into a very successful program. Imagine that we had imported Mirage 2000 in the 2005-2007 time frame. LCA may have been cancelled and India would have had to pay 45+ million for upgrading the Mirage 200 in the next few years.

Right now MK1 is as capable as the non upgraded mirages and Mk2 promises to be better than upgraded mirages. (The wait for the LCA has been long but it was certainly worth it)
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Re: Kaveri & Aero-Engine: News & Discussion

Post by maitya »

Indranil wrote:Certainly, it is for new Kaveri.
Sorry I may have missed recent news items etc, but what is this new kaveri?
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Re: Kaveri & Aero-Engine: News & Discussion

Post by Suresh S »

Indranil thank you for sharing
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Re: Kaveri & Aero-Engine: News & Discussion

Post by prasannasimha »

I used to meet APJAK regularly in our CVTS conferences. He used to make it a point to attend and when he became president he was a special guest and honored guest etc.In fact in one of our conferences he demonstrated VSAT technology(It was fledgling then). ery astute and always having insightful comments
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Re: Kaveri & Aero-Engine: News & Discussion

Post by Rakesh »

Question: https://twitter.com/abhayjj/status/1049260787963846656 ---> You tweeted that noise problem with Kaveri has been sorted out and Snecma had certified in their technical audit it to be good enough to tie it up to an airframe. What is actually happening at Kaveri's front?

Answer: https://twitter.com/SJha1618/status/1049261451330772992 ---> The idea is to make flight worthy derivatives of the Kaveri for demonstration flights on a Tejas test vehicle. But that won't cut it, because India needs a 96 KN class low bypass turbofan and that will mean a new core.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by Rakesh »

https://twitter.com/SJha1618/status/1049240141443694593 ---> By 2030, India must ensure that it removes the glaring gaps in its techno-manufacturing repertoire. To do that it must:

1. Develop & make its own modern jet engines
2. Have fabs based on different semiconductor materials on its soil
3. Build supercomputers with domestic hardware.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by Rakesh »

https://twitter.com/SJha1618/status/1049239390277402624 ---> It's zimble onlee. If you have your own mature jet engine tech, you develop a high degree of innate sanction resilience and strategic independence. Nobody can really ground you.

https://twitter.com/SJha1618/status/1049239077608800256 ---> And the negotiation for collaboration on jet engine technology must be led by the apex level of the defence eco-system. Merely GTRE or DRDO being in charge of making a deal won't cut it.

https://twitter.com/SJha1618/status/1049238329726709761 ---> I am even willing to go to the extent of suggesting that India should forego local assembly of the fighter imports, if the other side is willing to share total know why for turbofans + end to end local manufacturing of the engine in India.

https://twitter.com/SJha1618/status/1049237626698391554 ---> In my opinion, as long as Ash Carter was still in the Pentagon, some US tech would have trickled to India via DTTI. Now I don't think much can happen. Case in point is the failure of the much vaunted Joint Working Group on Jet Engine Technology.

https://twitter.com/SJha1618/status/1049236764206845952 ---> The tender to buy 110 more 'multi-role' aircraft for the IAF should be closely tied to the transfer of aero-propulsion technologies.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by ramana »

What new core! It has to be new engine.

That's what we have been wailing about since last ten pages.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by Rakesh »

https://twitter.com/SJha1618/status/1049235412407840769 ---> The IAFs newly setup 'Make PMU' (PMU= Project Management Unit) should put jet engine technology development at the top of its list. If India has to have its own low bypass turbofans for the Tejas MK-2 & the AMCA, GTRE, HAL and IAF will have to work very closely.

https://twitter.com/SJha1618/status/1049235847394938880 ---> On the strategic side of things, India has received collaborative support chiefly from Russia followed by France. France has been especially helpful with Space technology. For domestic jet engine development, India's MoD must directly work out a partnership with either.

https://twitter.com/SJha1618/status/1049212255764504577 ---> New Delhi must ensure that @IAF_MCC flies an operational Tejas variant with an indigenous jet engine on its 100th Anniversary. [That is 14 years from now. Not far at all].
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Re: Kaveri & Aero-Engine: News & Discussion

Post by JayS »

ramana wrote:What new core! It has to be new engine.

That's what we have been wailing about since last ten pages.
Saar, new core = new engine.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by ramana »

So what was all that BS about SAFRAN says Kaveri ready fro airplane integration?
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Re: Kaveri & Aero-Engine: News & Discussion

Post by Rakesh »

Ramana-ji, the existing Kaveri turbofan which GTRE shut down in 2014 was revived in 2016. Safran has completed the technical audit and has stated that the engine is ready to be test flown on a Tejas test bed. However, the expected wet thrust will likely not exceed 70 to 80+ kN. GTRE will test the engine, certify it and then move on to a new engine = new core.

However the present Kaveri is well below the 95 kN that the Tejas (especially the Mk2 variant) needs. But I do not think the development to flight test phase will take the same length of time as the exsiting Kaveri turbofan. The only way to get to 95 kN (and higher for AMCA) is crystal blade technology. And reportedly - as per Saurav Jha - DMRL (Defence Metallurgical Research Laboratory) has developed a prototype. Please see this tweet from 21 April 2018...

https://twitter.com/SJha1618/status/987670985959772160 ---> Legacy image of high pressure turbine blade (HPTB) and high pressure turbine vane (HPTV) developed by DRDO's DMRL using single crystal casting process. HPTB is on the Right. HPTV on the left.

Image

No one is going to give us this technology. DMRL did that all on her own. The much vaunted Jet Engine Technology Joint Working Group (JETJWG) between India and the US fizzled out with G.E. refusing to help GTRE on making the Kaveri work. However they wanted to examine the engine to see how far off GTRE is from making a working engine. Go Figure!

France only did audit of the existing Kaveri. But even the French (Snecma-Safran) will not provide crystal blade technology and neither will the Russians (Saturn or Klimov) or the British (Rolls Royce).

Why help a future competitor? If I was the CEO of Pratt & Whitney, General Electric, Saturn, Klimov, Rolls Royce or Snecma-Safran....what incentive do I have to assit GTRE? That is suicide.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by Neshant »

Rakesh wrote:Ramana-ji, the existing Kaveri turbofan which GTRE shut down in 2014 was revived in 2016. Safran has completed the technical audit and has stated that the engine is ready to be test flown on a Tejas test bed. However, the expected wet thrust will likely not exceed 70 to 80+ kN. GTRE will test the engine, certify it and then move on to a new engine = new core.
If they will move on to a new core, why are they even certifying it.

Are they planning on using it in a drone?


You are right, expect no help from foreign aircraft engine companies.

Rather expect them to try every trick in the book to sink the project.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by Rakesh »

Neshant, I definitely want GTRE to certify the existing Kaveri. I want GTRE to go through the entire gamut of modern engine development. Certification is the final step for the current Kaveri. GTRE needs to learn and understand that process. GTRE must not be second guessing on certification processes when a new engine comes along and then run to Snecma-Safran or whoever else. We must not be dealing with that then. Absorb what we can now and use that for the next series of engines that come along.

Otherwise, we will never progress. And a certified turbofan is a MUST HAVE for Hindustan. This is the elixir that gives Hindustan respect on the international stage. This is the meat & potatoes that makes Hindustan indepedent.

Even at 70 - 80 kN wet thrust, the existing Kaveri - once certified - can be used on other platforms and even on the Tejas as a LIFT type aircraft.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by Neshant »

Rakesh wrote: Even at 70 - 80 kN wet thrust, the existing Kaveri - once certified - can be used on other platforms and even on the Tejas as a LIFT type aircraft.

I doubt it will ever see its usage on the Tejas.

The certification of just about anything in aerospace is a long and expensive affair.

Not only would the engine have to be certified, the Tejas would have to be re-certified with the new engine.

From my experience in the civilian aerospace sector, just about every component has to be certified to the Nth degree at great expense & time. Even the simplest of components end up costing an arm and a leg having to put it through the certification process - which is a must if it ever is to land up on an aircraft.

No country can afford to spend time & money certifying an engine that does not go into mass production.

Someone correct me if I'm wrong.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by Prasad »

The non afterburning Kaveri is slated to be used for the UCAV last I heard.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by Mukesh.Kumar »

Neshant wrote:
Rakesh wrote: Even at 70 - 80 kN wet thrust, the existing Kaveri - once certified - can be used on other platforms and even on the Tejas as a LIFT type aircraft.

I doubt it will ever see its usage on the Tejas.

The certification of just about anything in aerospace is a long and expensive affair.

Not only would the engine have to be certified, the Tejas would have to be re-certified with the new engine.

From my experience in the civilian aerospace sector, just about every component has to be certified to the Nth degree at great expense & time. Even the simplest of components end up costing an arm and a leg having to put it through the certification process - which is a must if it ever is to land up on an aircraft.

No country can afford to spend time & money certifying an engine that does not go into mass production.

Someone correct me if I'm wrong.
Neshant, valid points, but as discussed in the forum, just like LCA is development of a whole industry in the guise of a 4th Gen plane, Kaveri is the development of an whole engine industry in the guise of a single engine. Even if we take help to develop Kaveri, if we manufacture here, we can see the creation of an eco- system of vendors. So however, much expensive it is, Kaveri is a project of utmost national importance. And I would posit that we invest in the program.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by chetak »

Rafale offsets

A lot of the offset component is being earmarked for the kaveri engine




Image
JayS
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Re: Kaveri & Aero-Engine: News & Discussion

Post by JayS »

ramana wrote:So what was all that BS about SAFRAN says Kaveri ready fro airplane integration?
Thats about existing Kaveri. Sjha was talking about the one that LCA Mk2 would need (and eventually Mk1 would as well as it gains some weight in future) now which is 95-100kN, and perhaps AMCA could use uprated version from same family.

Typically a low bypass jet engine like Kaveri is designed with limited (e.g. 10-20% thrust increase) organic performance increase margin with technology infusion and some fine tuning of design expected to come in foreseeable future. Beyond 10% itself one typically needs significant design efforts. Anything more than 15-20% and the aerothermodynamic cycle falls out of the sweet spot it was optimized for. Hence complete redesign is needed. And engine core is mostly the bottleneck in such situations. Hence a new family of engine starts with a new core design.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by dinesh_kimar »

The ISRO analogy helps us see things clearly.

Their struggles from 1986 till January 2014 , with a successful indigenous CUSP launch, are well documented.

The Kaveri core is sound, like an MTR masala dosa. Multiple sources have verified this, incl. in parliament.

A small amount of detailed Engineering and flight test , and we should be in F-404 levels of thrust.

An MTBO of 1000-2000 hours would be acceptable , with future marks doing better.

The trainer and CAS version can easily use this.

ISRO struggled for 28 years, with dedicated infrastructure at LPSC installed in 2008. GTRE should take a leaf from ISRO's book and solder on for some more time.

***K. Radhakrishna apparently brought together a good team (some out of retirement, like Rolls Royce with Stanley Hooker), made stiff design reviews and gave clear instructions to solve problems. I have heard that the turbo pumps were made more robust, the pipe brazing process more reliable, better materials, etc.on CE 7.5.

That ugly black CUSP is a marvel of Indian engineering, much like the Kaveri deserves to be.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by chetak »

dinesh_kimar wrote:The ISRO analogy helps us see things clearly.

Their struggles from 1986 till January 2014 , with a successful indigenous CUSP launch, are well documented.

The Kaveri core is sound, like an MTR masala dosa. Multiple sources have verified this, incl. in parliament.

A small amount of detailed Engineering and flight test , and we should be in F-404 levels of thrust.

An MTBO of 1000-2000 hours would be acceptable , with future marks doing better.

The trainer and CAS version can easily use this.

ISRO struggled for 28 years, with dedicated infrastructure at LPSC installed in 2008. GTRE should take a leaf from ISRO's book and solder on for some more time.

***K. Radhakrishna apparently brought together a good team (some out of retirement, like Rolls Royce with Stanley Hooker), made stiff design reviews and gave clear instructions to solve problems. I have heard that the turbo pumps were made more robust, the pipe brazing process more reliable, better materials, etc.on CE 7.5.

That ugly black CUSP is a marvel of Indian engineering, much like the Kaveri deserves to be.
An MTBO of 1000-2000 hours would be acceptable, with future marks doing better.
sirji,

How are such arbitrary assumptions being made??

Any data or sources that say so??
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Re: Kaveri & Aero-Engine: News & Discussion

Post by chetak »

Mukesh.Kumar wrote:
Neshant wrote:

I doubt it will ever see its usage on the Tejas.

The certification of just about anything in aerospace is a long and expensive affair.

Not only would the engine have to be certified, the Tejas would have to be re-certified with the new engine.

From my experience in the civilian aerospace sector, just about every component has to be certified to the Nth degree at great expense & time. Even the simplest of components end up costing an arm and a leg having to put it through the certification process - which is a must if it ever is to land up on an aircraft.

No country can afford to spend time & money certifying an engine that does not go into mass production.

Someone correct me if I'm wrong.
Neshant, valid points, but as discussed in the forum, just like LCA is development of a whole industry in the guise of a 4th Gen plane, Kaveri is the development of an whole engine industry in the guise of a single engine. Even if we take help to develop Kaveri, if we manufacture here, we can see the creation of an eco- system of vendors. So however, much expensive it is, Kaveri is a project of utmost national importance. And I would posit that we invest in the program.
At least, as proof of concept, the certification has to be done.

Let them gain some real hands on working experience at this end of the performance spectrum too. It will not go to waste.

Currently, we have almost NIL expertise in this area.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by JayS »

dinesh_kimar wrote:
An MTBO of 1000-2000 hours would be acceptable , with future marks doing better.
It better be acceptable. The Russian engines powering our front-line fighter have 1000hrs of MTBO and 2000hr of Total Technical life. :lol: :lol:

If Kaveri can manage 1000hrs of MTBO, it would have already outdone what Safran can do with Heli engines in real life by long margin, especially given Heli engines do not operate that hot inside. :wink:
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Re: Kaveri & Aero-Engine: News & Discussion

Post by chetak »

JayS wrote:
dinesh_kimar wrote:
An MTBO of 1000-2000 hours would be acceptable , with future marks doing better.
It better be acceptable. The Russian engines powering our front-line fighter have 1000hrs of MTBO and 2000hr of Total Technical life. :lol: :lol:

If Kaveri can manage 1000hrs of MTBO, it would have already outdone what Safran can do with Heli engines in real life by long margin, especially given Heli engines do not operate that hot inside. :wink:
Russian engines are built on a different design philosophy and maintenance philosophy too, different from their equivalent western counterparts.

Just quoting arbitrary figures and then trying to justify them is not going to cut any ice.

BTW, and not judging or trolling, it is exactly this attitude
It better be acceptable
that pisses off customers no end and that's how the journey down the slippery slope usually begins in almost every customer funded project.

TBO etc would have been discussed with prospective customers and the figures to shoot for would already be written down in some specific requirement document, signed by all.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by dinesh_kimar »

^ MTBO seems ok, SDRE standards.

No customer anguish, loss of face, etc.

RD-33 => 1200 hr (*Advertised)
M-53 => 2000 hr
F-100 => 750 hr
Al-31 (actual) => 500 hr

F-404 is 4000-6000 hr
F-135 apparently 20000 hr.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by JayS »

chetak wrote:
JayS wrote:
It better be acceptable. The Russian engines powering our front-line fighter have 1000hrs of MTBO and 2000hr of Total Technical life. :lol: :lol:

If Kaveri can manage 1000hrs of MTBO, it would have already outdone what Safran can do with Heli engines in real life by long margin, especially given Heli engines do not operate that hot inside. :wink:
Russian engines are built on a different design philosophy and maintenance philosophy too, different from their equivalent western counterparts.

Just quoting arbitrary figures and then trying to justify them is not going to cut any ice.

BTW, and not judging or trolling, it is exactly this attitude
It better be acceptable
that pisses off customers no end and that's how the journey down the slippery slope usually begins in almost every customer funded project.

TBO etc would have been discussed with prospective customers and the figures to shoot for would already be written down in some specific requirement document, signed by all.
You are right he was throwing random figures. I just wanted to put the numbers he is implying to be a sorry figure, in real life perspective. Its not like Kaveri is designed to achieved 4000hrs MTBO anyway. And how many fighter engines have more than 2000hrs MTBO in real life...?? We have some idea on Kaveri's life numbers for various modules. Some time back some of those figures were posted on this thread. May not be exact but definitely gives the ballpark numbers.

WRT what you said, different philosophy cannot be rationale behind discriminating against Kaveri. If 1000hr MTBO is acceptable for everyone for Su-30MKI which are even more important than LCA as far as their place in overall scheme is concerned, I don't see why Kaveri should be put through more hardship for acceptance at least to start with. We have rather bad MTBO numbers of some western engines too. So design philosophy is not exactly the reason always. 1000-2000hr MTBO is an excellent number for any ab initio engine. Another factor to consider is that LCA itself has rather low design life as of today of 3000hr. With that in mind these numbers look very acceptable. The target MTBO number must be written somewhere of coarse. But not everything is achievable in one shot. A matured customer who is well versed with engineering challenges understands the intricacies and would make concessions when needed so the project stays on path and the designers get time to fix the issues while other things like certification and induction go on smoothly which need not stop for these issues. Even F404 have had very serious lifing issues which has reduced lives of some of its components to 30% of intended life numbers in early 1990s. USN kept using them with restrictions. I'm sure IAF is also one such matured customer, which evident from their attitude with other engines they have with them. In fact exactly the same argument can be made for LCA too. LCA also has "poor" design life as of today as compared to even Russian maal, let alone western counterparts. But IAF has taken them nonetheless. I have no doubts that LCA will see significant increase in its certified life in coming years. Same can happen with Kaveri. So yes, 1000-2000MTBO better be acceptable to start with. If we wait until it can have 3000-4000hr MTBO which hardly any engine in the world has then Kaveri is doomed for ever.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by chetak »

JayS wrote:
chetak wrote:
Russian engines are built on a different design philosophy and maintenance philosophy too, different from their equivalent western counterparts.

Just quoting arbitrary figures and then trying to justify them is not going to cut any ice.

BTW, and not judging or trolling, it is exactly this attitude that pisses off customers no end and that's how the journey down the slippery slope usually begins in almost every customer funded project.

TBO etc would have been discussed with prospective customers and the figures to shoot for would already be written down in some specific requirement document, signed by all.
You are right he was throwing random figures. I just wanted to put the numbers he is implying to be a sorry figure, in real life perspective. Its not like Kaveri is designed to achieved 4000hrs MTBO anyway. And how many fighter engines have more than 2000hrs MTBO in real life...?? We have some idea on Kaveri's life numbers for various modules. Some time back some of those figures were posted on this thread. May not be exact but definitely gives the ballpark numbers.

WRT what you said, different philosophy cannot be rationale behind discriminating against Kaveri. If 1000hr MTBO is acceptable for everyone for Su-30MKI which are even more important than LCA as far as their place in overall scheme is concerned, I don't see why Kaveri should be put through more hardship for acceptance at least to start with. We have rather bad MTBO numbers of some western engines too. So design philosophy is not exactly the reason always. 1000-2000hr MTBO is an excellent number for any ab initio engine. Another factor to consider is that LCA itself has rather low design life as of today of 3000hr. With that in mind these numbers look very acceptable. The target MTBO number must be written somewhere of coarse. But not everything is achievable in one shot. A matured customer who is well versed with engineering challenges understands the intricacies and would make concessions when needed so the project stays on path and the designers get time to fix the issues while other things like certification and induction go on smoothly which need not stop for these issues. Even F404 have had very serious lifing issues which has reduced lives of some of its components to 30% of intended life numbers in early 1990s. USN kept using them with restrictions. I'm sure IAF is also one such matured customer, which evident from their attitude with other engines they have with them. In fact exactly the same argument can be made for LCA too. LCA also has "poor" design life as of today as compared to even Russian maal, let alone western counterparts. But IAF has taken them nonetheless. I have no doubts that LCA will see significant increase in its certified life in coming years. Same can happen with Kaveri. So yes, 1000-2000MTBO better be acceptable to start with. If we wait until it can have 3000-4000hr MTBO which hardly any engine in the world has then Kaveri is doomed for ever.
No body is comparing the kaveri with russki engines.

If anything the kaveri has a fairly robust western sort of design influence so far, mostly because our guys have been educated that way, and again especially in some of their choice of alloys for the engine parts. This has not been done with adequate risk analysis so as to preclude US sanctions. Some of their choices for the alloys can only be described as "rash" or to put it diplomatically "avoidable".

I suspect that Kaveri will have improved TBOs as time goes by and more data is gathered on its performance and replaced parts are deeply analyzed for wear and tear, as well as why some of them failed before the scheduled replacement, either on running hours basis or calendar basis.

The 1000hr for the SU is not "accepted" in the way that you mean. It is a planned and scheduled replacement with these TBO figures being FACTORED in, specifically in the logistics chain, warehousing and in the stocking pattern to support this TBO and a little float to cater for exigencies.

A new engine/airframe is built with the best TBO that can be safely achieved. It matters not a whit what the life of the airframe is. Kaveri may not fly only on this one aircraft, so the designers would not even consider airframe life.

It is the job of logistics to match the TBO of the engine or overhaul cycles of the airframes and plan the inventory of the spares package accordingly. They have to deliver the part to the engineer's hand, as needed, when needed and where needed.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by JayS »

chetak wrote:
The 1000hr for the SU is not "accepted" in the way that you mean. It is a planned and scheduled replacement with these TBO figures being FACTORED in, specifically in the logistics chain, warehousing and in the stocking pattern to support this TBO and a little float to cater for exigencies.

A new engine/airframe is built with the best TBO that can be safely achieved. It matters not a whit what the life of the airframe is. Kaveri may not fly only on this one aircraft, so the designers would not even consider airframe life.

It is the job of logistics to match the TBO of the engine or overhaul cycles of the airframes and plan the inventory of the spares package accordingly. They have to deliver the part to the engineer's hand, as needed, when needed and where needed.
Thats right. And the same can be done for Kaveri as well if it happens to have 1000hrs MTBO. Technically speaking fairly low number for MTBO can be dealt with with proper logistics, but then other operational constraints and ownership cost too come into picture hence a those also need to be considered. Since we are already dealing with 1000hrs MTBO on Su-30MKI and looking at Su-30MKI utilisation numbers, its a fairly good benchmark to compare with.

Anyway, all I wanted to point out was 1000-2000hr MTBO is not as poor as the poster tried to imply. They are quite respectable figures.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by chetak »

JayS wrote:
chetak wrote:
The 1000hr for the SU is not "accepted" in the way that you mean. It is a planned and scheduled replacement with these TBO figures being FACTORED in, specifically in the logistics chain, warehousing and in the stocking pattern to support this TBO and a little float to cater for exigencies.

A new engine/airframe is built with the best TBO that can be safely achieved. It matters not a whit what the life of the airframe is. Kaveri may not fly only on this one aircraft, so the designers would not even consider airframe life.

It is the job of logistics to match the TBO of the engine or overhaul cycles of the airframes and plan the inventory of the spares package accordingly. They have to deliver the part to the engineer's hand, as needed, when needed and where needed.
Thats right. Technically speaking fairly low number for MTBO can be dealt with with proper logistics, but then other operational constraints and cost too come into picture hence a those also need to be considered. Since we are already dealing with 1000hrs MTBO on Su-30MKI without issues, thats a fairly good benchmark to compare with.

Anyway, all I wanted to point out was 1000-2000hr MTBO is not as poor as the poster tried to imply. They are quite respectable figures.
we purchased the SU when it was already flying and probably also in squadron service. We couldn't change anything. All the numbers were a fait accompli.

Here, we are building both aircraft and engine from the ground up.

Let's just shoot for the best figures we can get.

One can rarely match the TBOs of the engine and airframe on any aircraft in the world, not military not civil. So, the designers of one should not be influenced by the designers of the other on this parameter.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by ramana »

We don't have input from direct designers or the design review team except for tidbits from half knowledge reporters.
Kaveri has inlet fan, compressor and core.
So where is problem and more importantly what is the problem?
chetak
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Re: Kaveri & Aero-Engine: News & Discussion

Post by chetak »

ramana wrote:We don't have input from direct designers or the design review team except for tidbits from half knowledge reporters.
Kaveri has inlet fan, compressor and core.
So where is problem and more importantly what is the problem?

Nor should such details be available on an open forum.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by JayS »

chetak wrote: Let's just shoot for the best figures we can get.
..the designers of one should not be influenced by the designers of the other on this parameter.
Now you are doing exactly the same that you were objecting to, previously. Thats as arbitrary a statement as it gets. Who knows whats the best we can achieve, until we deploy Kaveri in service and see real life numbers. And there is no precedence to benchmark with for us. Setting up unrealistic numbers is also detrimental to the project. No one really does that in Aerospace. If you don't have your own historical benchmark, then you use others' data and experience. In short, we cannot get around being not influenced with what others are doing and have been able to achieve. Plus there is a definitive connection to the other programs which is the Physics of the whole thing. Design philosophies can influence the design parameters only so much. Finally Physics dictates the terms.

I think I said all I had to say on this. 1000hr MTBO is quite respectable number for any fighter jet engine. Going by Su-30MKI's utilisation numbers, that would give 8-10yrs between overhauls.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by ramana »

Chetak and JayS, Long ago I read in Interavia that once Kaveri manages cumulative performance of 100 hours the designers would accept putting on the Tejas.
This was an article during development circa 1990s.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by chetak »

ramana wrote:Chetak and JayS, Long ago I read in Interavia that once Kaveri manages cumulative performance of 100 hours the designers would accept putting on the Tejas.
This was an article during development circa 1990s.
Which designers, saar??

Kaveri or tejas??

They each may not have the same perspective.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by ramana »

Tejas designers wanted engine have cumulative 1000 hours run.
chetak
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Re: Kaveri & Aero-Engine: News & Discussion

Post by chetak »

ramana wrote:Tejas designers wanted engine have cumulative 1000 hours run.
There you go!!

That's quite a significant variation in perspectives of the two design teams, no??

Each design team seems to have buttered the toast on different sides.

One would err on the side of abundant caution and go with the views of the jejas team or reach a flight safe and viable engineering compromise after joint analyses and discussion, and also including the flight test team right from the get-go.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by ramana »

So how many hours is the engine designers shooting for?
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Re: Kaveri & Aero-Engine: News & Discussion

Post by JayS »

Ramana saar, what hours specifically..?

If its testing hours, Kaveri has almost 3000hrs testing hours under its belt. Its been mentioned somewhere that another 1000hr of ground resting and perhaps 100hrs of flight testing is needed before putting it on LCA. Some tender for flight testing was out some time back IIRC.

Re whatever was said in 1990s, I think they had no idea what they were talking about, if they said Kaveri will go on LCA after 1000hrs of testing. I still cant believe the original Kaveri program never included any flight testing. I dont know who were smoking what while drawing the program outline.
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Re: Kaveri & Aero-Engine: News & Discussion

Post by chetak »

ramana wrote:So how many hours is the engine designers shooting for?
Unlike the easier testing of a commercial aero engine, relatively speaking, a military aero engine, especially one designed to operate on a single engined fighter will have to undergo punishing and brutal tests at various combat simulated flight regimes, with rapid to almost instantaneous changes in pressure, temperature, mass flow and fuel flow and angle of attack variations and still keep performing reliably and optimally.

The design of such tests alone will need an experienced and knowledgeable team which may or may not be available in house. This is what will worry the tejas designers more than anything else.

I have a nasty feeling that it may take a lot many more flight hours on the engine before anyone is confident enough to use it

Whatever one may say about russki engines, one has to wonder how in hell they manage to keep those engines running without surge or stall during a brutal manoeuvre (engine wise) like the Su-27 Pugachev's cobra.


https://www.youtube.com/watch?v=GQMJ2f6V-SE

Su-27 Pugachev's cobra

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