Twinblade
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Kaveri Engine
- Thread starter natarajan
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My guess is that its related to reliability. I have read somewhere that the early first gen single crystal blades of US or russia were having almost the same performance as developed casted blades. So you really won't gain much in performance if the single crystal blades are itself not much developed, but the cost will be quite high. So here I'm really not expecting DRDO/GSRE to come up with a single crystal blades better then the Americans, at the best it will of the same level as older soviet designs(RD93), or close to AL31 for which we got a lot of tot.
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The Failed Negotiations with Snecma for Engine Technology
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In the midst of sundry scams relating to defence procurement, the cut in the 2012-13 defence budget, and the usual handwringing over delays in various defence projects, an announcement with huge implications for India's search for self-reliance in defence production went unnoticed. Early this year, AjaiShukla, the Business Standard's defence correspondent, reported that the negotiation with the French company Snecma (the maker of the engine for the Dassault Rafale aircraft) for collaboration on India's Kaveri engine had collapsed. Perhaps because nobody has(so far)leveled allegations of corruption, the media and even defence analysts took no notice. But even a cursory look at this negotiation raises the suspicion that all was not above board.
The Gas Turbine Research Establishment (GTRE), a unit of the Defence Research and Development Organization (DRDO), has been working on the Kaveri turbofan engine for the Light Combat Aircraft (LCA) since the 1980s. The LCA first flew in January 2001, powered by a US engine as an interim measure. DRDO did manage to build the Kaveri engine. Unfortunately, the engine failed its high altitude tests in 2005. Even if the Kaveri had performed well, it still would have been inadequate for its original purpose of powering the LCA. What the GTRE had succeeded was in developing an engine using 1970s technology according to specifications fixed in the early 1980s. In the meanwhile, the LCA had become heavier than anticipated, necessitating a more powerful engine. To enhance its power without increasing its size and weight, GTRE needed new technologies that advanced countries had developed in the intervening years for its "hot section"—mainly single crystal turbine blades, "blisk" (integrated rotor disk and blades) and thermal barrier coating for the blades.
In 2006, MoD decided to seek foreign collaboration from reputed foreign engine manufacturers to produce an improved Kaveri. The problem is that countries do not part with such technologies easily. But India had an ace up its sleeve: its proposed medium multirole combat aircraft (MMRCA) deal.Back in 2008, it was reportedthat DRDO had presented MoD a technology wish list, to be obtained in the form of offsets for defence acquisitions. MoD, however, preferred to buy these technologies as part of the contracts for the import of weapons systems. Accordingly, the RfP for the MMRCA deal reportedly prescribed the technologies the winning vendor must part with. Aero engine technology was surely the military technology India needed the most. As it has been widely reported, losing the MMRCA deal would have made the survival of several of the bidders as combat aircraft manufacturers doubtful. Considering these stakes, the MMRCA bid offered India the best leverage to obtain advanced aero-engine technology from the winner.
But the government of India does not believe in using its leverage in bargaining for what it needs most. It issued a stand-alone RfP for collaboration for developing an improved Kaveri in 2006. A separate RfP for the MMRCA deal followed a year later. The US General Electric (GE) and Britain's Rolls Royce refused any form of participation. America's Pratt&Whitney is on record having expressed its willingness to aid the Kaveri project.
But later reports said it was willing to participate only as a consultant. In 2008, MoD selected Snecma over Russia's NPO Saturn as the collaborator for the Kaveri. It was reported that it would take 4 years to develop and certify a new engine, after which the technology would be transferred to GTRE. MoD entered into separate negotiations with Snecma on this deal even as it was processing the MMRCA proposals.
These negotiations dragged onfor more than three years. Meanwhile, the Dassault Rafale, powered by a Snecma engine, emerged as the lowest bidder among those shortlisted for the MMRCA and MoD began contract negotiations with it. Was Snecma playing a game, waiting for the finalization of the Rafale deal? It would seem so. It appeared that in a bizarre twist, at this stage India had allowed France to make the Rafale deal an offset for the engine technology deal.
As what was thought to be price negotiations with Snecma progressed, it also appeared thatSnecma was really offering the "ECO" core it had already developed and that it would pass on the technology to the DRDO only after 15 years. Considering the pace at which engine technology progresses, the know-how, by the time Snecma transferred it to GTRE, would have become obsolete. MoD rejected this proposal. Evaluation of the MMRCA contenders was then going on. Snecma quickly climbed down, agreeing to ToT as soon as GTRE could absorb it.
MoD then began negotiations with Snecma for a joint venture for the development of the Kaveri. Minister of State for DefencePallamRajutold Business Standard: "(Snecma) is willing to co-develop an engine with us; they are willing to go beyond just transfer of technology. It is a value-added offer that gives us better technology than what we would get from ToT from Eurojet(the maker of the Typhoon's engine) or GE." This was misleading.
GE and Eurojet were not contenders for the collaboration with GTRE. The technology they were offering was part of a deal for the import of 99 engines for the LCA Mark II. The kind of technologies sought for the collaboration on the Kaveri engine were not sought for this deal. Officially, no specifics of what technologies Snecma would offer have been disclosed. A senior DRDO official said two years ago that the work share between GTRE and Snecma would be 50:50; that price negotiations would be completed "within a month"; and that GTRE would gain the intellectual property rights for the new engine. Aviation Week reported in March 2012 that an agreement on the joint venture to develop and build a 20,230-lb-thrust engine would be reached by June that year. Snecma would provide "exhaustive know-how" on the technologies and manufacturing processes GTRE lacked, the sources for the report claimed.
In early January this year came the news that MoD has dropped the proposed deal with Snecma. No reason has been reported for this unexpected development. Quite likely Snecma raised the cost of its technologies or refused to pass on the intellectual property rights for the new engine to GTRE as it seems to have promised earlier. At this point, it looks like a classic case of bait and switch. It is hard not to conclude that Snecma was stringing India along with promises it had no intention of keeping, until almost the end of the Rafale price negotiations, and revealed its hands when it could no longer put MoD off. Snecma, by bidding for the collaboration, prolonging the negotiations for several years, and finally hardening its position, has made India's engine development programme lose precious time.
The decision to build a 20,230-lb-thrust engine is also questionable. Such an engine would be inadequate for India's future needs. The 22,000lb thrust GE engine is being procured for the initial batch of the LCA Mark II ordered by the IAF. The improved Kaveri, with a 10 per cent less thrust, would not be adequate for later batches of the LCA, should the IAF decide to order more of them. It is also doubtful if it would be suitable for the Advanced Medium Combat Aircraft (AMCA) which India is planning.
The AMCA, a stealth aircraft, would need to have an internal weapons bay, fairly high internal fuel capacity, and supercruise capability. If the LCA program imparted any lesson to Indian military planners, it is that the AMCA is going to turn out to be heavier than now planned. Developing a 20,000lb class engine now for it makes no sense. Presumably, it is the maximum level to which Snecma's ECO core can be developed.
As Air Marshall Philip Rajkumar (rtd.) recounts in his book The Tejas Story, the DRDO and the IAF had a falling out in the 1980s over the choice of partners for developing the LCA's flight control system. The IAF wanted to go with Dassault, while the DRDO preferred Lockheed Martin. This disagreement had caused the IAF to wage a decades-long cold war against the DRDO and the LCA project in particular. Quite possibly,DRDO bought peace with the IAF by accepting the latter's preference for Snecma.
In the wake of the VVIP chopper scam, Defence Minister A. K. Antony has promised corrective action. He cannot act until he finds out what really happens behind the scenes in the procurement process. The complete lack of transparency in all matters relating to defence makes it easy for unscrupulous elements to manipulate the system. Antony must order a thorough inquiry into the whole Kaveri-Snecma saga. Several questions relating to this affair need answers.
Who was pushing for delinking the Kaveri collaboration from the MMRCA tender? What specifically did Snecma offer in its response to the RfP, and at what price? Why did the negotiations drag on for so many years, and on what basis were predictions of imminent agreement fed to the media on a regular basis (see here and here)? What were the reasons for the termination of the negotiations? This charade could not have gone on for so long unless senior levels of the GTRE, MoD, and the IAF were involved. A top-to-bottom shakeup in the MoD, DRDO, and the services would inspire some confidence that it is not going to be, once again, business as usual.
About the author:
Appu Kuttan Soman is a diplomatic historian, and was a Research Fellow at the Belfer Center for Science and International Affairs at the Harvard Kennedy School of Government, Harvard University from 2007-2009. His research interests include arms control, nuclear history, and South Asian security. He is the author of Double-Edged Sword: Nuclear Diplomacy in Unequal Conflicts: The United States and China, 1950-1958 (Praeger, 2000), and Through the Looking Glass: Diplomacy, Indian Style. He holds a PhD in US diplomatic history from Vanderbilt University and master's in Psychology and bachelor's in History and Psychology from Andhra University in India. He was an Associate of the Charles Warren Center for Studies in American History at Harvard University from 1995-1997.
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----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
In the midst of sundry scams relating to defence procurement, the cut in the 2012-13 defence budget, and the usual handwringing over delays in various defence projects, an announcement with huge implications for India's search for self-reliance in defence production went unnoticed. Early this year, AjaiShukla, the Business Standard's defence correspondent, reported that the negotiation with the French company Snecma (the maker of the engine for the Dassault Rafale aircraft) for collaboration on India's Kaveri engine had collapsed. Perhaps because nobody has(so far)leveled allegations of corruption, the media and even defence analysts took no notice. But even a cursory look at this negotiation raises the suspicion that all was not above board.
The Gas Turbine Research Establishment (GTRE), a unit of the Defence Research and Development Organization (DRDO), has been working on the Kaveri turbofan engine for the Light Combat Aircraft (LCA) since the 1980s. The LCA first flew in January 2001, powered by a US engine as an interim measure. DRDO did manage to build the Kaveri engine. Unfortunately, the engine failed its high altitude tests in 2005. Even if the Kaveri had performed well, it still would have been inadequate for its original purpose of powering the LCA. What the GTRE had succeeded was in developing an engine using 1970s technology according to specifications fixed in the early 1980s. In the meanwhile, the LCA had become heavier than anticipated, necessitating a more powerful engine. To enhance its power without increasing its size and weight, GTRE needed new technologies that advanced countries had developed in the intervening years for its "hot section"—mainly single crystal turbine blades, "blisk" (integrated rotor disk and blades) and thermal barrier coating for the blades.
In 2006, MoD decided to seek foreign collaboration from reputed foreign engine manufacturers to produce an improved Kaveri. The problem is that countries do not part with such technologies easily. But India had an ace up its sleeve: its proposed medium multirole combat aircraft (MMRCA) deal.Back in 2008, it was reportedthat DRDO had presented MoD a technology wish list, to be obtained in the form of offsets for defence acquisitions. MoD, however, preferred to buy these technologies as part of the contracts for the import of weapons systems. Accordingly, the RfP for the MMRCA deal reportedly prescribed the technologies the winning vendor must part with. Aero engine technology was surely the military technology India needed the most. As it has been widely reported, losing the MMRCA deal would have made the survival of several of the bidders as combat aircraft manufacturers doubtful. Considering these stakes, the MMRCA bid offered India the best leverage to obtain advanced aero-engine technology from the winner.
But the government of India does not believe in using its leverage in bargaining for what it needs most. It issued a stand-alone RfP for collaboration for developing an improved Kaveri in 2006. A separate RfP for the MMRCA deal followed a year later. The US General Electric (GE) and Britain's Rolls Royce refused any form of participation. America's Pratt&Whitney is on record having expressed its willingness to aid the Kaveri project.
But later reports said it was willing to participate only as a consultant. In 2008, MoD selected Snecma over Russia's NPO Saturn as the collaborator for the Kaveri. It was reported that it would take 4 years to develop and certify a new engine, after which the technology would be transferred to GTRE. MoD entered into separate negotiations with Snecma on this deal even as it was processing the MMRCA proposals.
These negotiations dragged onfor more than three years. Meanwhile, the Dassault Rafale, powered by a Snecma engine, emerged as the lowest bidder among those shortlisted for the MMRCA and MoD began contract negotiations with it. Was Snecma playing a game, waiting for the finalization of the Rafale deal? It would seem so. It appeared that in a bizarre twist, at this stage India had allowed France to make the Rafale deal an offset for the engine technology deal.
As what was thought to be price negotiations with Snecma progressed, it also appeared thatSnecma was really offering the "ECO" core it had already developed and that it would pass on the technology to the DRDO only after 15 years. Considering the pace at which engine technology progresses, the know-how, by the time Snecma transferred it to GTRE, would have become obsolete. MoD rejected this proposal. Evaluation of the MMRCA contenders was then going on. Snecma quickly climbed down, agreeing to ToT as soon as GTRE could absorb it.
MoD then began negotiations with Snecma for a joint venture for the development of the Kaveri. Minister of State for DefencePallamRajutold Business Standard: "(Snecma) is willing to co-develop an engine with us; they are willing to go beyond just transfer of technology. It is a value-added offer that gives us better technology than what we would get from ToT from Eurojet(the maker of the Typhoon's engine) or GE." This was misleading.
GE and Eurojet were not contenders for the collaboration with GTRE. The technology they were offering was part of a deal for the import of 99 engines for the LCA Mark II. The kind of technologies sought for the collaboration on the Kaveri engine were not sought for this deal. Officially, no specifics of what technologies Snecma would offer have been disclosed. A senior DRDO official said two years ago that the work share between GTRE and Snecma would be 50:50; that price negotiations would be completed "within a month"; and that GTRE would gain the intellectual property rights for the new engine. Aviation Week reported in March 2012 that an agreement on the joint venture to develop and build a 20,230-lb-thrust engine would be reached by June that year. Snecma would provide "exhaustive know-how" on the technologies and manufacturing processes GTRE lacked, the sources for the report claimed.
In early January this year came the news that MoD has dropped the proposed deal with Snecma. No reason has been reported for this unexpected development. Quite likely Snecma raised the cost of its technologies or refused to pass on the intellectual property rights for the new engine to GTRE as it seems to have promised earlier. At this point, it looks like a classic case of bait and switch. It is hard not to conclude that Snecma was stringing India along with promises it had no intention of keeping, until almost the end of the Rafale price negotiations, and revealed its hands when it could no longer put MoD off. Snecma, by bidding for the collaboration, prolonging the negotiations for several years, and finally hardening its position, has made India's engine development programme lose precious time.
The decision to build a 20,230-lb-thrust engine is also questionable. Such an engine would be inadequate for India's future needs. The 22,000lb thrust GE engine is being procured for the initial batch of the LCA Mark II ordered by the IAF. The improved Kaveri, with a 10 per cent less thrust, would not be adequate for later batches of the LCA, should the IAF decide to order more of them. It is also doubtful if it would be suitable for the Advanced Medium Combat Aircraft (AMCA) which India is planning.
The AMCA, a stealth aircraft, would need to have an internal weapons bay, fairly high internal fuel capacity, and supercruise capability. If the LCA program imparted any lesson to Indian military planners, it is that the AMCA is going to turn out to be heavier than now planned. Developing a 20,000lb class engine now for it makes no sense. Presumably, it is the maximum level to which Snecma's ECO core can be developed.
As Air Marshall Philip Rajkumar (rtd.) recounts in his book The Tejas Story, the DRDO and the IAF had a falling out in the 1980s over the choice of partners for developing the LCA's flight control system. The IAF wanted to go with Dassault, while the DRDO preferred Lockheed Martin. This disagreement had caused the IAF to wage a decades-long cold war against the DRDO and the LCA project in particular. Quite possibly,DRDO bought peace with the IAF by accepting the latter's preference for Snecma.
In the wake of the VVIP chopper scam, Defence Minister A. K. Antony has promised corrective action. He cannot act until he finds out what really happens behind the scenes in the procurement process. The complete lack of transparency in all matters relating to defence makes it easy for unscrupulous elements to manipulate the system. Antony must order a thorough inquiry into the whole Kaveri-Snecma saga. Several questions relating to this affair need answers.
Who was pushing for delinking the Kaveri collaboration from the MMRCA tender? What specifically did Snecma offer in its response to the RfP, and at what price? Why did the negotiations drag on for so many years, and on what basis were predictions of imminent agreement fed to the media on a regular basis (see here and here)? What were the reasons for the termination of the negotiations? This charade could not have gone on for so long unless senior levels of the GTRE, MoD, and the IAF were involved. A top-to-bottom shakeup in the MoD, DRDO, and the services would inspire some confidence that it is not going to be, once again, business as usual.
About the author:
Appu Kuttan Soman is a diplomatic historian, and was a Research Fellow at the Belfer Center for Science and International Affairs at the Harvard Kennedy School of Government, Harvard University from 2007-2009. His research interests include arms control, nuclear history, and South Asian security. He is the author of Double-Edged Sword: Nuclear Diplomacy in Unequal Conflicts: The United States and China, 1950-1958 (Praeger, 2000), and Through the Looking Glass: Diplomacy, Indian Style. He holds a PhD in US diplomatic history from Vanderbilt University and master's in Psychology and bachelor's in History and Psychology from Andhra University in India. He was an Associate of the Charles Warren Center for Studies in American History at Harvard University from 1995-1997.
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rvjpheonix
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@p2prada you said that the entire AL 31 was made in India from raw materials. But then what about this?
UMPO starts the delivery of 920 AL-31FP engines to India - News - Russian Aviation - RUAVIATION.COM
MPO starts the delivery of 920 AL-31FP engines via Rosoboronexport to India. It is the largest contract signed with a foreign customer during post-Soviet era, the enterprise's press-service reports.
"Under the conditions of general contract on launching the licensed production of Su-30MKI aircraft and AL-31FP engines in India signed in 2000, the Indian party had a right to purchase a number of additional kits for AL-31FP engines as an option", - UMPO reminded.
The abovementioned option was exercised in October 2012. Following the agreement signed the deliveries will be continued over the next ten years and the first batch of kits will be delivered to India in the first quarter of 2013, UMPO noted.
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There was a "follow on" option which was exercised. Does this mean we have been just assembling the engines?
UMPO starts the delivery of 920 AL-31FP engines to India - News - Russian Aviation - RUAVIATION.COM
MPO starts the delivery of 920 AL-31FP engines via Rosoboronexport to India. It is the largest contract signed with a foreign customer during post-Soviet era, the enterprise's press-service reports.
"Under the conditions of general contract on launching the licensed production of Su-30MKI aircraft and AL-31FP engines in India signed in 2000, the Indian party had a right to purchase a number of additional kits for AL-31FP engines as an option", - UMPO reminded.
The abovementioned option was exercised in October 2012. Following the agreement signed the deliveries will be continued over the next ten years and the first batch of kits will be delivered to India in the first quarter of 2013, UMPO noted.
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There was a "follow on" option which was exercised. Does this mean we have been just assembling the engines?
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Other than the casing , nothing is made here ,
we were always assembling the engines,
All critical tech part of AL-31 like HPT blades, compressor blades , shafts are imported from Russia,(referred to as kits in your article, and referred to as ,"raw material " by some guys to bolster their lie that the russians have transferred all critical tech to HAL , koraput for making Al-31 , including BLISK and SCB from raw mineral stage,)
Youcan read MAitya's post in BR LCA thread and get confirmation on this.
http://forums.bharat-rakshak.com/viewtopic.php?p=1587428#p1587428
everything posted by the guy you referred to in your post is false .
No one in his right mind will deliver the full technology of the above mentioned core components on the platter to us, however much we pay,
Remember the cryogenic engine tech.
On he contrary it is the DMRL which is transferring critical tech developed in house to HAL koraput,
(not the russians ),
including Adour mk 811 engine blades and eight sets of advances nickel based super alloy engine blades and vanes for GTRE kaveri,
The ceramic core supplied by them is used in creating single crystal aerofoil casting for kaveri(HPT turbine blades and vanes)
http://drdo.gov.in/drdo/pub/techfocus/2011/TFApril2011.pdf,
If you can please post the entire PDF in the thread, so that every one can see for themselves,
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p2prada
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Our first engine from raw materials stage was made in 2010.
This is a second contract for 920 engines over the first contract for 900+ engines (970 IIRC) signed in 2000.
The largest Russian-Indian contract - News - Politics - Russian Radio
Total AL-31 engines for IAF MKIs will be around 2000 by 2030. This contract is also following the same phases as before. Kits from Russia followed by indigenous production in a few years.
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How many engines are needed in total?
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That's Depend upon by our Needs ..Each and Every engine had life's of 750 hours to 1000 hours
pmaitra
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Interesting news: India Considers New Partnership Options For Kaveri Engine | Aviation International News
Also, I found this comment by Roshan, worth replicating:
Also, I found this comment by Roshan, worth replicating:
Twinblade
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Jingoistic tripe. Somebody needs to tell Roshan that RD-33 delivered more thrust 30 years back than Kaveri does today. I have said this before and I am going to repeat it here for the sake of clarity, single crystal blade technology is not a unified technology, it is like a triangle, the three arms being
1) High end materials suited for your design needs
2) Blade design (cooling via air flow vents inside, mechanical loading keeping in mind the choice of materials)
3) Manufacturing infrastructure.
People always ask question as to why Kaveri does not have single crystal blade despite us manufacturing Al-31 ? The answer is the Al-31 manufacturing has given us manufacturing technology which is probably the last concern. The material used in Al-31 might be useless to our design needs as AL-31 blade is significantly larger than what is needed in Kaveri, which results in greater coolant flow through the blades in Al-31. Until 1 and 2 are not brought into order, 3 is useless.
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kaveri with FADEC is way better than the RD-93,
Only people ignorant of engine tech will write that Rd-93 achieved this thrust way back , thirty years before,because the bypass ratio of Rd-93 is 0.49.
Thw low by pass of 0.16 chose for kaveri compares well with the 0.2 by pass ratio of the latest f-35 engines.
The Next F-35 Lightning's Engine Adapts for Flight, Fight, and Beyond
http://forums.bharat-rakshak.com/viewtopic.php?f=3&t=3351&start=2120
post by geeth in this link elegantly states the selection of low by pass ratio for kaveri,
as mass flow through the core is high in low bypass ration engines cooling is efficient and a higher TET is not required,also the space required for engine too is low,it will have a higher SFC and higher noise levels,and only lesser fuel can be pumped for after burner
In high bypass ration engine as mass flow through the core is less lesser cooling of the core needs a higher TET and it will need a large space meaning more weight as well, but it will have a bette rSFC and lesser noise, but more fuel can be pumped for after burner.
So it is entirely possible considering low metallurgy tech in india prevailing then(even now)GTRE chose a low bypass ratio engine for Kaveri effort,Still lot needs to be done though,
Also with the new emphasis on Super cruise requirements for newer 5th gn engines the key advantage of high by pass ratio engines ,i.e more fuel available for higher after burner thrust is overshadowed by more emphasis on higher dry thrust per weight of the engine(where low bypass ratio engines like kaveri have a lead) , becaus these low bypass ratio engines can return a better figure here.
So insted of focussing on the brute higher after burner thrust of high bypass engines of the earlier era, time has come to look at the other advantages of low bypass ratio engines like kaveri.
What needs to be focussed now is reducing the weight by 100 odd Kgs and increasing the engine MTBO specs.
Only thing that stopped kaveri from entering Tejas is the increased weight of the fighter resulting partly from new IAF demands and partly due to under estimation of weight.
So kaveri follows the latest global design principles for a single engined fighter engine,
For more informed opinions other than ranting," this guy is nationalist tripe", and ,"I know that Rd-93 achieved it more than 30 years back"
http://forums.bharat-rakshak.com/viewtopic.php?f=3&t=6726
So kaveri achieving dry thrust figures itself is something very critically important for our future engine programs as it validated many design assumptions and generates ,"true empirical data ", for all our future engine designs,
the shortfall in wet thrust can be looked into in future
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[pdf]http://drdo.gov.in/drdo/pub/techfocus/2011/TFApril2011.pdf[/pdf]
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Really do we make engine blades of Al-31 in Koraput?
Then what is inside the 920 ,"kits " to be delivered by Russians for Al-31 engines?
Then what is inside the 920 ,"kits " to be delivered by Russians for Al-31 engines?
Twinblade
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In addendum to what I said, the importance of material science cannot be understated. As per public domain info, two super alloys have been developed by DMRL for single crystal blades for aero engine HPT, DMD4 and DMS4, or at least this was the state a few years back.
However, DMS4, which has a higher temperature capability has an estimated 20-25 degree celsius shortfall from concurrent super alloys used in GE, P&W and Snecma engines. One may ask that in engines where temperatures in several hundreds of degree Celcius, what difference does this small shortfall make ?
The answer lies in the fact that modern engines operate several hundred degree celicius above the temperature capability of the material. Forget about mechanical stability, the material is supposed to melt at those temperatures. The blades are cooled by forcing cold air through hollow channels inside them. Thus every degree rise in material capability results in several times higher rise in TET as shown in the graph above. As a rule of thum, one degree rise in temperature capability results in five degree rise in TET. 10 degree rise in material capability results in double service life for the components. So by a short fall of 20-25 degrees, we are looking at a severe shortfall in performance.
More or less same, with different gearbox and auxiliaries placement.
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Can the answer be anything less obvious? The reason I asked is to understand how many engines of this variety are needed for our forces and how many can be manufactured in India rather than importing. We have got around 2000 engines built from the raw kits imported from Russia. What is the use of getting and having TOT if we don't build majority of the engines in India from the raw material stage? Even a wild guess works for me !!
Twinblade
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A further addendum to the post. The current DS blades of the Kaveri engine are made of CM247LC alloy (marked in a circle in the first graph). Read and weep gentlemen jingos, Kaveri would have to be first certified fully with the current DS blades following which the Boffins will keep tweaking the engines with DMS4/DMD4 (or any new superalloy they might have made in the meanwhile) SC blades, which are third generation, while the world moves on to fifth generation blades and we run around with a begging bowl for fourth generation blade technology. I suggest the thread title to include "Abandon hope all ye enter here" to reflect the reality of this project.In addendum to what I said, the importance of material science cannot be understated. As per public domain info, two super alloys have been developed by DMRL for single crystal blades for aero engine HPT, DMD4 and DMS4, or at least this was the state a few years back.
However, DMS4, which has a higher temperature capability has an estimated 20-25 degree celsius shortfall from concurrent super alloys used in GE, P&W and Snecma engines. One may ask that in engines where temperatures in several hundreds of degree Celcius, what difference does this small shortfall make ?
The answer lies in the fact that modern engines operate several hundred degree celicius above the temperature capability of the material. Forget about mechanical stability, the material is supposed to melt at those temperatures. The blades are cooled by forcing cold air through hollow channels inside them. Thus every degree rise in material capability results in several times higher rise in TET as shown in the graph above. As a rule of thum, one degree rise in temperature capability results in five degree rise in TET. 10 degree rise in material capability results in double service life for the components. So by a short fall of 20-25 degrees, we are looking at a severe shortfall in performance.
p2prada
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Obviously, we need the number of engines we ordered.
The engine life is 1600-2000 hours. 2000 hours is the manufacturer figure.
Airframe life is 4000 hours for MKI. This is not counting the MLU. So, we will need minimum 4 engines for each MKI. If we bring in MLUs we will need two to four more for the entirety of the MKI's lifetime.
Basically, we will need a pair of engines for one MKI every decade it is in service. So, over 40 years that is 4 sets of engines.
If we upgrade the AL-31FP to 117S standard, then we will need just a pair of engines every 20 years, bringing down the costs of operation by a huge margin. This may have been taken into consideration since we will need a set amount of numbers for maintenance and reserves. It is possible we will have 2 pairs of engines for the first 20 years followed by one pair of engines for the final 20 years.
So, 6*270 = 1620 engines for all MKIs for 40 years + 270 engines as reserve. This is just my guesstimate. If we start using 117S standard engine even earlier then we will have more reserves which makes more sense.
p2prada
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It is an open source and accepted fact that we are well behind the world in materials technology.
