Kaveri & Aero-Engine: News & Discussion

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tejas
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Re: Kaveri & aero-engine discussion

Postby tejas » 01 Aug 2012 07:25

In the article, the Kaveri project director says with help from Snecma the 90 kN engine will take 5 years to fructify.

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Re: Kaveri & aero-engine discussion

Postby pentaiah » 01 Aug 2012 08:27

I for one believe that if Kaveri project is turned over to BARC they will deliver the engine in 1 year or 2 max with one test it might even be flight worthy and into serial production.
They have all the expertise based one poster here named Alok N. I don't know why he is not here anymore?

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Re: Kaveri & aero-engine discussion

Postby Neela » 01 Aug 2012 11:15

Prem Kumar wrote: But his larger point was that "blaming the lack of exotic materials/blisks" is taking the easy way out.

Ah yes, I do remember this too from him.

But if the Program Manager of Kaveri says that there is a 150 degree difference in temperature and shortfall of X.Y in compression ratio leading due to a difference of Z amount of thrust, and this can be overcome through the three things he listed, either you believe him or you don't. Simples.

pentaiah wrote:

I for one believe that if Kaveri project is turned over to BARC they will deliver the engine in 1 year or 2 max with one test it might even be flight worthy and into serial production.
They have all the expertise based one poster here named Alok N. I don't know why he is not here anymore?


Sirji, apparently everyone including BARC and ISRO can sort the problem except GTRE.
MOvement of scientists across different institutions is common no? Why, what is stopping Dr.Saraswat throwing more expertise and resources from BARC at Kaveri. Are you telling him something he does not know already? I am thinking BARC/ISRO have no clue either - this is a different beast. And until such time someone from BARC takes over the project and delivers, I am right when I say BARC has no clue.

Here is another anecdote. Relative from my inlaws side works for BHEL. Anna Univ alumni who has worked his way up since the 1980s. Now BHEL has been in the power gen business for several decades. Yet we import the core turbine. Where was BARC and ISRO all this time?

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Re: Kaveri & aero-engine discussion

Postby Prem Kumar » 02 Aug 2012 03:07

NRao wrote:N3 was/is no ordinary run-of-the-mill person.


Yes, I know. I was pointing out to Neela a contrarian viewpoint (N3's) about the problems in Kaveri being more about engineering discipline, rather than materials science.

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Re: Kaveri & aero-engine discussion

Postby SaiK » 02 Aug 2012 03:29

I would say, seriously we need to cancel the snecma project. cause:

1. The time to take a decision about AMCA requirements [read Dr. Saraswat's replies/video] that they are waiting for the right specifications and don't want to make basic mistakes on kNs.

2. There is no real benefit in jump-starting here.. in fact no company in the world would do it for free. Even if we pour billions, it is not worth it, and all patents will be held by snecma.. still, they would make us pay for it, and keep the real core tech with them.. they want the ECO core in for sure.

3. They have nothing in their line to proof a working copy of 100kN engine. IAF has clearly stated in this requirement. If that is not adhered to, then write on anybody's forehead that a massive project failure to happen in the future.

4. We have a fantastic milestone of flying this 80kN wet wala on the IL platform.. next thing is mandatory to get it ported on the LCA TD versions.

5. Parallel start working on the 100kN wet wala.. Just keep the GE414 IN version as the baseline spec., in terms of T:W/kNs/size/weight/technology/etc.

5 steps to glory.. it is a must.. delink this to R&D only, while GE414 continues. THis is important for the future.

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Re: Kaveri & aero-engine discussion

Postby suryag » 02 Aug 2012 03:44

Armchair chaprasi uvvacha - The ruskies were able to compensate for exotic materials by designing the aircraft around the engine dimensions. I remember seeing some program where the tumansky engine in mig25 was made and the airframe redesigned to accommodate the huge air intakes(agreed it is turbo jet) but by scaling the components in the current kaveri we can possibly reach 100KN(gurus?) the thing is it will need a new airframe and may not fit the aMCA frame requirements.

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Re: Kaveri & aero-engine discussion

Postby NRao » 02 Aug 2012 03:47

I think it too late for discussions. The die has been cast. Going back would mean - if I read the situation right - that lot would have to undone.

I am just hoping that India got, as part of the deal, access to a computer based nuke testing facility. What good are all these French air crafts if India cannot field a good sized nuke?

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Re: Kaveri & aero-engine discussion

Postby SaiK » 02 Aug 2012 04:01

^what is too late for discussion? we are talking about the up-thrusted version right?

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Re: Kaveri & aero-engine discussion

Postby NRao » 02 Aug 2012 06:14

If we are talking of the Snecma deal, then yes, I think it is too late to not move forward.

As someone else has already posted it looks like (to me at least) that the Blisk, SC, etc are part of the M2000 upgrade. I do not think the Rafale was part of it, although the price for it may play a part.

Besides pouring funds into Indian resources, which has to be done no matter what, means decades before India sees results.

IF the news reports are right then the offer is worth it IMHO. A mature native engine is a must, one in which the entire manufacturing process is Indian. Hopefully, which is what I would plan for, is to use these technologies to leapfrog in a few areas.

Let us see, I am not too hopeful, for whatever reason urgency is not a thing that is commonly experienced. India seems to be in a universe of its own. Patience is what is required in abundance.

I had huge hopes for the AMCA. No more. I still think it will be a product that will be out-of-this-world ............ when it comes. (As an aside, I think they can make the missiles they plan on happen. But when is the question.)

Sorry for the ramble.

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Re: Kaveri & aero-engine discussion

Postby NRao » 02 Aug 2012 06:18

Prem Kumar wrote:
NRao wrote:N3 was/is no ordinary run-of-the-mill person.


Yes, I know. I was pointing out to Neela a contrarian viewpoint (N3's) about the problems in Kaveri being more about engineering discipline, rather than materials science.


Apologies. I should have been more clear.

However, I do think that both are issues in India. For sure India lacks the knowledge database that is required to support leading edge technologies and like Ncubed pointed out the discipline.

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Re: Kaveri & aero-engine discussion

Postby SaiK » 02 Aug 2012 06:36

somewhere out there in the dark corner..

v
v
v


hope shall return.
it is just being shadowed by suite-case less men.

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Re: Kaveri & aero-engine discussion

Postby NRao » 02 Aug 2012 06:50

MAN, SaiK!!!!

You ought to be writing thrillers!!!!

What the heck are you doing on BR?

Men in Black ......................

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Re: Kaveri & aero-engine discussion

Postby srai » 09 Nov 2012 08:32

Unable to copy it, China tries building own engine

By David Lague and Charlie Zhu

HONG KONG (Reuters) - China has designed nuclear missiles and blasted astronauts into space, but one vital technology remains out of reach. Despite decades of research and development, China has so far failed to build a reliable, high performance jet engine.

This may be about to change. China's aviation sector is striving for a breakthrough that would end its dependence on Russian and Western power plants for military and commercial aircraft.

Beijing is evaluating a 100 billion yuan plan to galvanize a disjointed and under-funded engine research effort, aviation industry officials say. The giant, state-owned Aviation Industry Corporation of China AVIC.L, China's dominant military and commercial aviation contractor, has been lobbying hard for the extra money, officials familiar with the details say.

AVIC, with more than 400,000 employees and 200 subsidiaries including 20 listed companies, has already set aside about 10 billion yuan of its own funds for jet engine development over the next three years.

The engine financing plan is under high-level discussion in Beijing, said Zhao Yuxing, an official at the securities office of Shanghai-listed Xi'an Aero-Engine Plc (600893.SS), a key military engine-making unit of AVIC. "What we know is our company has been included in the strategic programme, which is designed to greatly develop and support the engine industry," he said by phone from his company's headquarters in the northwestern city of Xi'an.

China's military industry as a whole has suffered from Tiananmen-era bans on the sale of military equipment from the United States and Europe. Moreover, foreign engine-makers have been loath to transfer technology. That has prevented China from taking its usual route to closing a technology gap: copying it.

Some Chinese aviation industry specialists forecast that Beijing will eventually spend up to 300 billion yuan on jet engine development over the next two decades.

"China's aircraft engines have obviously been under-invested," said Wang Tianyi, a defence sector analyst with Shanghai's Orient Securities. "One hundred billion yuan is not a huge amount of money in the engine world."

JEALOUSLY GUARDED SECRETS

While AVIC's long term priority is to develop high performance engines for military aircraft, it is also trying to design power plants for passenger aircraft in the world's fastest growing civil aviation market. Based on projected demand from Western aircraft manufacturers, engines for new passenger aircraft delivered in China could be worth more than $100 billion over the next 20 years.

"Historically, all major players in aerospace have possessed both airframe and engine design capabilities," said Carlo Kopp, the Melbourne, Australia-based founder of Air Power Australia, an independent military aviation think tank. "Until China can design and produce competitive engines, the performance and capabilities of Chinese aircraft designs will be seriously limited by what technology they are permitted to import."

For China's aviation engineers, the traditional short cuts of extracting intellectual property from foreign joint venture partners or simply copying technology from abroad have so far delivered minimal results.

Foreign engine manufacturers including General Electric (GE.N), Snecma, a subsidiary of French aerospace group Safran (SAF.PA), Rolls Royce Plc (RR.L) and Pratt & Whitney - a unit of United Technology Corp (UTX.N), jealously guard their industrial secrets, limiting the transfer of know-how and opportunities for intellectual property theft.

However, China may be poised to win access to technology from an expanding range of commercial aviation joint ventures with these companies. China's ability to develop engines for passenger aircraft could have considerable potential for technology transfer to the military, experts say.

THE BOTTLENECK IN ENGINES

Under AVIC's plan, fragmented engine research and development would be consolidated to minimize competition and duplication of effort.

A legacy of Maoist-era dispersal of defence industries, engine research institutes and aerospace manufacturing companies are scattered about the country in cities including Shenyang, Xi'an, Shanghai, Chengdu and Anshun.

AVIC plans to inject its major engine related businesses into Xi'an Aero- Engine as part of this consolidation, the listed company said in its 2011 annual report. "There is widespread consensus that engines have become a bottleneck constraining the development of China's aviation industry," the report said.

China faces a daunting challenge. Only a handful of companies in the United States, Europe and Russia have mastered this expertise.

"Modern jet engine technology is like an industrial revolution in power," said Andrei Chang, a Hong Kong-based analyst of the Chinese military and editor of Kanwa Asian Defence Magazine. "Europe, the U.S. and Russia have hundreds of years of combined experience, but China has only been working on this for 30 years."

Established manufacturers have laboured on research and development since the 1950s to build safe and reliable engines with thousands of components that function under extremes of temperature and pressure. This involves state-of-the-art technologies in design, machining, casting, composite materials, exotic alloys, electronic performance monitoring and quality control.

Since then, the big players have collected vast stores of performance and operational data from existing engines that gives them a head start in designing new versions with improved fuel efficiency and reliability that airlines now demand. And, for commercial engines, all of the design and manufacturing processes must be carefully coordinated and exhaustively documented to satisfy aviation certification authorities.

"The reason so few can do it is because it is really, really difficult," says Richard Margolis, a former regional director of Rolls Royce in northeast Asia.

High performance military jet engines are crucial to Beijing's long term plan to increase the number of frontline fighters and strike aircraft in its air force and naval aviation units. These aircraft are a key element of a long term military build-up aimed primarily at securing military dominance over Taiwan and a vast swathe of disputed maritime territory off China's east and southern coasts.

Due to the export bans on military equipment to China, Beijing has been forced to rely on imported fighters from Russia, reverse engineered copies of these Russian aircraft, and some home-grown designs. This strategy has delivered rapid results. Since 2000, China has added more than 500 advanced fighters and strike aircraft with capabilities thought to equal all but the most advanced U.S. stealth aircraft. At the same time, it has also sharply reduced the number of obsolete aircraft based on Soviet-era designs, military experts say.

MANUFACTURING PROCESS

A clear example of this progress was on display recently when a Chinese-made J-15 jet fighter practiced "touch and go" circuits on China's first aircraft carrier, the newly commissioned Liaoning. These manoeuvres suggest that J-15 pilots and crews will soon master take-offs and landings from the carrier at sea.

Foreign and Chinese military experts were quick to point out that the J-15, one of China's newest military aircraft, was powered by a pair of Russian Al-31 turbofans - they power almost all of China's frontline aircraft. Reports in the Russian media say Moscow has sold more than 1,000 engines from the A1-31 family to China with further, substantial orders in the pipeline.

While Chinese engineers have been able to reverse-engineer Russian airframes, the engines have been much more difficult to copy without access to the complex manufacturing processes. AVIC subsidiary and China's lead military jet engine maker, Shenyang Liming Aero-Engine Group Corporation, has been working on a homegrown equivalent, the WS-10 Taihang, but this power plant has so far failed to meet performance targets after testing on the J-15 and other fighters, Chinese and Western military experts say.

The Chinese military is expected to introduce another 1,000 advanced fighters over the next two decades, according to Chinese defence sector analysts. However, anger over reverse engineering and wariness of China's growing military power has made Moscow reluctant to supply engines more advanced than the Al-31. Without imported or locally built versions of these engines, China will be unable to build aircraft that could compete with the latest U.S. or Russian stealth fighters, experts say.

While military jets are strategically important, the commercial market is potentially much bigger. Boeing (BA.N) forecasts China will need an extra 5,260 large passenger aircraft by 2031. Bombardier Inc. (BBDb.TO) projects demand for business jets will reach 2,400 aircraft over the same period. With each aircraft requiring at least two engines plus spares, total demand could reach 16,000 engines with an estimated average cost of $10 million each at current prices.

China plans to compete for some of these aircraft orders with two locally built passenger aircraft, the 90-seat ARJ21 regional jet and the 150-seat C919. GE (GE.N) will supply engines for the ARJ21. CFM International, a joint venture between GE and France's Snecma, won the contract to develop new engines for the C919. Some of these engines will be assembled at joint ventures in China.

Despite the intensified research effort and potential for technology transfer from these ventures, some experts say foreign engines will continue to rule the skies in China. "This won't change for 10 or 15 years," says Chang from Kanwa Asian Defence Magazine. (Editing by Bill Tarrant)

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Re: Kaveri & aero-engine discussion

Postby maitya » 09 Nov 2012 09:54

Thanks srai, just too many gems in it, for me let go this one ... :mrgreen:
srai wrote:Unable to copy it, China tries building own engine
By David Lague and Charlie Zhu

HONG KONG (Reuters) - China has designed nuclear missiles and blasted astronauts into space, but one vital technology remains out of reach. Despite decades of research and development, China has so far failed to build a reliable, high performance jet engine.
...
...
Beijing is evaluating a 100 billion yuan plan to galvanize a disjointed and under-funded engine research effort, aviation industry officials say. The giant, state-owned Aviation Industry Corporation of China AVIC.L, China's dominant military and commercial aviation contractor, has been lobbying hard for the extra money, officials familiar with the details say.
...
...
Some Chinese aviation industry specialists forecast that Beijing will eventually spend up to 300 billion yuan on jet engine development over the next two decades.

"China's aircraft engines have obviously been under-invested," said Wang Tianyi, a defence sector analyst with Shanghai's Orient Securities. "One hundred billion yuan is not a huge amount of money in the engine world."
Oouch ... 100b yuan is it? What was Kaveri's budget between? Good, so throwing money will solve this problem is it?
...
...
For China's aviation engineers, the traditional short cuts of extracting intellectual property from foreign joint venture partners or simply copying technology from abroad have so far delivered minimal results.
But but, when the SDREs "fail" to "get" the SCB tech from Lic Manufacturing of AL-31, why so much rona-dhona then? The sooper-dooper, all powelfull and tallel guys are also failing, no? Why so much shame and cowering when we the short-dark and inferior morons also "fail"?
...
...
"Modern jet engine technology is like an industrial revolution in power," said Andrei Chang, a Hong Kong-based analyst of the Chinese military and editor of Kanwa Asian Defence Magazine. "Europe, the U.S. and Russia have hundreds of years of combined experience, but China has only been working on this for 30 years."
...
...
While Chinese engineers have been able to reverse-engineer Russian airframes, the engines have been much more difficult to copy without access to the complex manufacturing processes. AVIC subsidiary and China's lead military jet engine maker, Shenyang Liming Aero-Engine Group Corporation, has been working on a homegrown equivalent, the WS-10 Taihang, but this power plant has so far failed to meet performance targets after testing on the J-15 and other fighters, Chinese and Western military experts say.
And aren't some already cowering in the China Thread with unveiling of the J20s and J30s - until the good surgeon took up his html scalpel, that is.
Enquiring minds also want to know, how much of technical complexity of a so-called 5th gen stealth fighter development can be attributed to development of credible latest gen turbo-fan engine tech

...
...

On a serious not though, I think some of previous posts (in the LCA thread) are relevant here as well - so cross-posting:

Reg. difficulty level of mastering an ab-intio turbofan dev (from our own Kaveri dev effort), irrespective of a decent de-risking/mitigating plan/path: Kaveri dev path
Cross-posting in full:
maitya wrote:
ramana wrote:maitya, To add to your post if the choice was to be RD-33, thenit should have been the GTRE own turbojet which alteast they had full design control of. It was the requirement for the turbofan which was bleeding edge technology at that time that led the Kaveri down the river!

The plan all along was to prove the plane with a proven engine and later ingetrate the engine.

The SLCA should be named after Sleek Smitha

Absolutely - basically, trying to graduate from a 64kN class turbojet (GTX37-14U) to a 80 kN turbofan, and that too while being intrinsically linked to almost an ab-intio aircraft development program in the background of our very very poor industrial base, we aimed too high. Plus given our Orephus experience about an decade or so less back then, it certainly looks almost an unobtanium to aim for.

But that's all with the luxury of a hindsight of course. 8)

As the contrasting theory can be, if GTRE had aimed for say a 10% dry and wet thrust creep (so 45kN to 49kN dry and 64kN to 70kN wet) in a 3 stage LP, 7 stage HP setup of the same turbojet, and be successful in say 2001/3 timeframe, GTRE would may well have been blamed for creating a "bulky, very underpowered and 2 gen less useless" engine. :roll:
People would have bayed for their blood for being too SDRE and navel-gazing in their outlook/planning. :((
(shiv, can always back this above claim of mine up by his piskological analysis of a desi mindset). :rotfl:

So IMHO, GTRE didn't frankly have any option but to aim for the Kaveri specs back then. :(
And they did try to de-risk it as much as possible by building,

1. first a turbofan version (GTX37-14UB) around very similar core-layout (3 LPC, 7 HPC, 1 HPT and 1 LPT) and achieving the baseline wet thrust level (IIRC 88kN was achieved, need to check though) by increasing the frontal area and with a modest BPR of 0.215. This ofcourse required playing around with the core airflow vol, essentially compensating for the inherent drop in airflow vol/mass due to the introduction of by-pass of trying to go from a turbojet to a turbofan.

2. then in GTX-35, going back to enhance/improve the baseline turbojet by trying to reduce the weight of the core by eliminating the 2 HPC stages (so 5 from 7), and trying to compensate with the inevitable drop in core airflow by increasing the Turbine Inlet Temperature and, to a some extent, by improving the combustor efficiency.
Of course, like any other turbojet, this even though may have given very close thrust parameters, wouldn't have been acceptable as is, on the dry and wet SFC counts.

So, when they decided to aim for GTX-35VS (which later got called as Kaveri - and the core as Kabini), they were basically trying to emulate the GTX37-14U to GTX37-14UB migration on GTX-35 (plus ofcourse other modern add-ons like FADEC, Flat rating etc).

GTRE most probably thought, they will be able to manage the drop in core-inflow vol/mass (from trying to introduce BPR to a turbojet design) by increasing the HPC stage number (from 5 to 6) - which IMVHO, was not a various ambitious thing to plan for, given their earlier history/experience of migrations.


Reg. importance of hard R&D on jet-engine dev initatives: From our Kaveri experince, on how even the so-called "basic" non-hot part of a jet-engine technology can be a stumbling back and mastering those require nothing but hard-nosed and tenacious R&D - simply throwing money and trying to buy or reverse-engineer will not work:
LCA News and Discussions - Pg 21 - Ref 1
LCA News and Discussions - Pg 21 - Ref 2

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Re: Kaveri & aero-engine discussion

Postby maitya » 09 Nov 2012 10:16

On second thoughts, I think cross-posting in full for the second link above (from LCA thread - reg importance of both turbine and compressor tech on turbofan engine developmental efforts vis-a-vis our Kaveri program) is relevant here.

LCA News and Discussions - Pg 21 - Ref 2
maitya wrote:There's a bit of truth that gets hidden when we try to do a RCA of the Kaveri failure and lay the blame singularly on our lack of SCB related metallurgical technology.

What needs to be understood also, is what we have failed to achieve in the non-hot part of the core itself i.e. the compressors.
Pls note, as per open source, the stage Pressure Ratio (SPR) achieved was only 1.6 (as opposed to the design goal of "Three stage axial flow LP compressor with a mass-flow rate of 78kg/sec, Pressure ratio of 3.4, Isentropic efficiency of 85% and surge margin >20%.".

Playing around with the turbine stages will not overcome this shortage, but re-designing and more importantly, refining the manufacturing process and the corresponding tolerance level of the Compressor blades would address this shortcoming.

The other sledge-hammer approach is to add one more compressor stage - but that will increase the weight of an already overweight engine (by 150Kg, it stands at 1265 Kg - while GE-404 weighs 1036 kg, Eurojet2000 weighs just 989Kg but still manages 90KN).

Betw, this is what the grand-mullah enqyoob-uddin gas-turbini had to say about this issue, long back, before he decided on his self-imposed BR-sanyayas ... quoting in full in here:
enqyoob wrote:It's a lot better than that. Note that stage pressure ratio for Kaveri is onbly about 1.3. Long way to improve, and this does not require SCB. Just good aerodynamics, or maybe just good fabrication of the existing design (based on other things I've seen, I suspect strongly that the actual fabrication quality control is where they lose 50% of their design performance). If they can get even this improved, they can probably save a lot of weight on the engine. Or they can beef up the turbine blades with the saved weight, or add cooling and increase T.i.T.

Also, the T.i.T is still a long way from getting to the levels where SCB is needed.

IOW, a number of small improvements, whose cumulative effect is a drastic improvement. Just plain hard work and good management and coordination.



Another goal was to have Afterburner to provide a 50% over and above the max dry thrust at efficiency of 88%.

The 72kN achieved vs 81kN goal there, most probably is directly linked to the shortfall in the core mass-flow. Increasing which will require improving both the compressor stage PR and also the Turbine-inlet-temperature by 150-200deg C. While the compressor stage PR issues can be resolved by next level of manufacturing process and CFD design tweaking etc, for increasing the turbine efficiency, we need the SCB and blisk-level manufacturing technology, which we haven't got.
What we have got is teh lab level SCB technology (with DMRL etc) which can demostrate say the 1900K level temperature tolerance on model SCB blades - but we have failed to scale it up to actual engine-blade level dimension. And apparently, the difficulty level of growing single crystals is exponentially proprotionate to the size itself.

Other key area where we lack is the TBC of these blades in those 1700-1900K domain.


So we are basically staring at two completely opposing cosntraints - increasing the mass-flow and thus the stage PRs and the OPR while reducing the overall weight (which can only be done by reducing either the compressor blade density or removing a compressor stage itself) of the engine itself. :shock:

Which, IMVVHO, is a dead-end when constrasted against our open-source-published technological capability. :(


These above mentioned problems have been quoted in the following link - Kaveri jet engine finally poised for first flight
“The reason was two-fold”, explains Mohana Rao. “The Kaveri turned out 15% heavier than we planned. From the planned 1100 kg, its final weight has gone up to 1265 kg.”

Meanwhile, the Tejas fighter also turned out heavier than planned, demanding a more powerful engine; the Kaveri’s maximum thrust of 65 Kilo Newtons (KN) is simply not enough. The air force has chosen American GE 404-IN engines, which produce 80 KN at full power, to power the first 20 Tejas fighters. And subsequent Tejas will get about 95 KN of thrust from a new-generation engine: the General Electric GE-414 and the Eurojet EJ200 engines are currently being evaluated.
...
“We need more thrust without increasing the size of the engine”, says Mohana Rao. “That means getting better technologies from a more experienced foreign partner. We have chosen (French aero-engine major) Snecma. The Defence Ministry has approved the tie-up.”


I've long exceeded my BR quota for atleast a couple of weeks - so back to lurk mode now. :mrgreen:

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Re: Kaveri & aero-engine discussion

Postby vina » 09 Nov 2012 11:40

So we are basically staring at two completely opposing cosntraints - increasing the mass-flow and thus the stage PRs and the OPR while reducing the overall weight (which can only be done by reducing either the compressor blade density or removing a compressor stage itself) of the engine itself.


Nah.. Basically mass flow rate will increase if you increase bypass ratio, but the core flow will drop and result in a higher turbine inlet temp.

Same with stage PR and OPR. The moment you start doing that , turbine inlet temp increases.

Engine weight will significantly reduce if you go for blisks and other advanced manufacturing techs and also go for a contra rotating spool and you hopefully can remove a couple of stator stages and make a shorter engine.

All conceptually fine on paper, but devilishly complex to do in real world without a great deal of slog, perseverance, experimentation, trial and error. So just get on with it. But fundamentally if you want a modern engine , you need cutting edge high temp materials for the turbine. No getting away from it. The rest is all kabootarbaazi.

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Re: Kaveri & aero-engine discussion

Postby SaiK » 09 Nov 2012 13:48

advanced materials and manufacturing techs for inner core is the main area, but I also think the probability of reducing weight increases if we consider advanced materials for external housing as well, right from smaller components and parts.

and imho, it is a lost cause analysis (basically a loser statement) when in design there was no SCB considerations for the 81kN, and suddenly at testing times, we say had it been SCB, we would have achieved it. just speaks volumes on our maturity. /sorry i could not resist this.

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Re: Kaveri & aero-engine discussion

Postby maitya » 09 Nov 2012 14:29

vina wrote:
So we are basically staring at two completely opposing cosntraints - increasing the mass-flow and thus the stage PRs and the OPR while reducing the overall weight (which can only be done by reducing either the compressor blade density or removing a compressor stage itself) of the engine itself.


Nah.. Basically mass flow rate will increase if you increase bypass ratio, but the core flow will drop and result in a higher turbine inlet temp.

Same with stage PR and OPR. The moment you start doing that , turbine inlet temp increases.

Vinaji, agree - but when I said "increasing the mass-flow", I meant core mass-flow - and I should have mentioned/appended "without changing the BPR" part as well.
Which, in lay man (like moi :P ) terms, in one way can be achieved by somehow making the compressor stages rotate at a higher rpm (for the same turning energy produced by the turbine) - this in turn can be done by making the various compressor stages lighter.

[speculation or wild thinking]
Wouldn't using lighter composites, since the temp gradient across the compressor stages are tolerable enough (at sub 300deg levels), achieve that (though machining them into such complex geometry will be a huge challenge etc).
[/speculation or wild thinking]
Blisks and contra-rotating spool etc (as you have pointed out) are other way of achieving that as well - another path would be to improve the compressor blade manufacturing process to reduce aerodynamic wastages etc.

IIRC (don't have the quote/proof handy though) Even the compressor blade geometry in kaveri is compromised as the initial compressor blade design couldn't be manufactured by some German firm, citing very poor production volume requirement to justify the cost of creating the fabrication unit etc.
Engine weight will significantly reduce if you go for blisks and other advanced manufacturing techs and also go for a contra rotating spool and you hopefully can remove a couple of stator stages and make a shorter engine.

All conceptually fine on paper, but devilishly complex to do in real world without a great deal of slog, perseverance, experimentation, trial and error. So just get on with it. But fundamentally if you want a modern engine , you need cutting edge high temp materials for the turbine. No getting away from it. The rest is all kabootarbaazi.

Absolutely.

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Re: Kaveri & aero-engine discussion

Postby SaiK » 09 Nov 2012 14:55

shape of the blades matter for higher efficiency.

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Re: Kaveri & aero-engine discussion

Postby Will » 10 Nov 2012 23:26

Any idea what happened to DRDO's proposed National Jet Engine project?????????????

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Re: Kaveri & aero-engine discussion

Postby member_23694 » 03 Dec 2012 21:53

India could test Kaveri engine on Tejas by end-2013

http://www.flightglobal.com/news/articl ... 13-379684/

any idea what thrust level has been reached till now, and what has improved in the recent past which has increased the
confidence level on the engine.
What is the current tech and reliability level of kaveri engine ?
Anyway good news :)

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Re: Kaveri & aero-engine discussion

Postby suryag » 04 Dec 2012 03:43

I wouldnt believe this even if PS or VKS said this so no question of believing unnamed sources

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Re: Kaveri & aero-engine discussion

Postby SaiK » 04 Dec 2012 03:49

I don't care who says it, or how much thrust it has..
I just want Kaveri ported to Tejas, and continuously used.

Rest is tranches.. go kaveri++!

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Re: Kaveri & aero-engine discussion

Postby Vivek K » 04 Dec 2012 06:31

This is just another way to get more money from the govenrment for a failed project. The date given is end of next year - so they can arrange for a full year of funding. Next Dec, it will be extended to end of 2014.

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Re: Kaveri & aero-engine discussion

Postby maitya » 04 Dec 2012 09:27

Vivek K wrote:This is just another way to get more money from the govenrment for a failed project. The date given is end of next year - so they can arrange for a full year of funding. Next Dec, it will be extended to end of 2014.

No Vivek K, this is seriously positive news.

Irrespective of the future of Kaveri (and Kabini) wrt LCA, it still needs to fly on the platform around which it was designed in the 1st place.

The Thrust shortfall is a non-issue as most of it's in the max wet thrust regime, which comes handy in a very rare situations (but the most important ones, so can't be diluted) of actual operational use.

I guess, LCA will attain supersonic speed with a Kaveri, as long as they have kept the ToW low i.e. attain the thrust-to-weight ratio by compensating the lack of wet thrust by a lower ToW.

Kaveri (and Kabini) is not yet tested in the supersonic regime - it can't be without integrating it with LCA (or a LCA like fighter platform). And that's a vital Engine performance regime on which GTRE has no real-world experience - that itself is well worth to justify this.

Also will be requiring testing the interface of the Kaveri fan with air-intake which down-converts the supersonic flow to a subsonic flow. Plus of course, the actual after-burner performance in a supersonic regime (and also in a subsonic regime) needs testing.

These (and I'm sure there are quite a few others) are absolutely gold-plated experience and empirical data points that no "friendly" nation will part with, JV or non-JV not-withstanding.

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Re: Kaveri & aero-engine discussion

Postby Vivek K » 04 Dec 2012 10:54

Maitya ji, I hope I am proven wrong and you right!

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Re: Kaveri & aero-engine discussion

Postby Singha » 04 Dec 2012 10:56

Plus putting it in a single engine tejas will also be a major milestone in safety and reliability of the engine systems if it works out.
Imo they should put it in a tejas trainer so rear seat can have all addl instruments needed to monitor the engine.

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Re: Kaveri & aero-engine discussion

Postby Pratyush » 04 Dec 2012 11:03

^^^

Considering that I have been reading about the Tejas flying with the Kaveri for the last 3 to 4 years. I will be pleasantly surprised, if the aircraft flies with the Kaveri end of 2013.

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Re: Kaveri & aero-engine discussion

Postby vina » 04 Dec 2012 11:54

Don't you think that first building up a confidence on a dual engined bird and then putting it on a single engined one will be a better approach?


They did test it in a 4 engined plane. So what is the logic behind going from 4 to 2 to 1 ? If reliable, it goes gets qualified on 4 and goes to 1 .

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Re: Kaveri & aero-engine discussion

Postby Singha » 04 Dec 2012 12:39

Indeed the f22 and f35 were never tested in twin engines probably.

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Re: Kaveri & aero-engine discussion

Postby suryag » 26 Dec 2012 09:19

Kaveri engine to fly futuristic unmanned aircraft

During this test the Kaveri did well, generating 49.2 KiloNewtons (KN) of “dry thrust”, marginally less than its target of 51 KN. But there was a serious shortfall in “wet thrust”; the Kaveri generated just 70.4 KN, well short of the targeted 81 KN.


GTRE has a three-fold plan for perfecting the Kaveri for the USAV. First, it will remove the design flaws that were detecting during testing in Russia in 2010-11; then, after ground testing in Bangalore, the Kaveri will undergo a round of confirmatory tests in Russia; finally, it will be fitted on a Tejas fighter for flight tests.



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Re: Kaveri & aero-engine discussion

Postby PratikDas » 26 Dec 2012 10:01

Given the general pessimism surrounding the Kaveri program, this is a moment to celebrate. Thank you MTCR for ensuring the survival of the Kaveri.

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Re: Kaveri & aero-engine discussion

Postby neerajb » 26 Dec 2012 10:42

nukavarapu wrote: Can the 4 engined plane test across high alphas? I am not as knowledgeable as you are and I was under impression that there is a situation at some angles, the engine fails to suck in air killing the thrust. I am not sure if they can simulate that using a 4 engined plane. Please do correct me if I am wrong. Thanks in advance!


Why not? High alpha doesn't mean the nose is pointing skywards at 45 degree etc. AF447 crashed with 35 degrees AOA while the nose up attitude was just 12 degrees. You can put a 747 to 90 degree AOA though it will crash for sure after that. In civilian jets where the engine is exposed, the likelyhood of thrust loss at high AOA is greater. The long air intake tunnel in military jets with all those doors/flaps makes sure the aircraft can pull higher AOA than their civilian counterparts. JMT.

Cheers....

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Re: Kaveri & aero-engine discussion

Postby SaiK » 26 Dec 2012 11:00

porting to LCA platform is a milestone in itself, given our past history of this technology maturity. Now, the next step can always be funded based on the past step. If the past step is always failure, then we take no step.

imho, porting to LCA, whatever thrust it has, test flights is mandatory for success. After that, it would be all changes and redesigning.. say, we have done it for 70kN, and we can do now more... btw, we also plan to change our management and engineering team as well.

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Re: Kaveri & aero-engine discussion

Postby Yagnasri » 26 Dec 2012 11:40

Gurus - Can Kaveri powered AC can be used as a small size Bomber - with limited manuvering capability?

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Re: Kaveri & aero-engine discussion

Postby keshavchandra » 26 Dec 2012 13:48

I still have a vision for kaveri to test it under running Tejas project (may as a separate LSP series) in spite the short falls in required wet thrust. Just integrate it with what the current Tejas project is, as the separate LSP may as a test bad for tejas trainer or bomber or as any other way (Rather then just take Kaveri primary for USAV). By this only we can retain the Kaveri for the aerial combat usability.
Its time to back link the both running projects (Kaveri with Tejas) under the limited or as the separate test bad.

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Re: Kaveri & aero-engine discussion

Postby chiragAS » 26 Dec 2012 16:03

From the same Ajai Shukla article

GTRE has asked the MoD for Rs 595 crore to develop the Kaveri dry engine for the USAV.


“We will take 48 months from the date we get clearance from the government, for completing 50 hours of testing the Kaveri on the Tejas LCA. During the last 12 months, we will actually fly the Tejas with the Kaveri,” says Ramnarayanan.


Question :?: when will MoD sanction that 595 crore for USAV integration
and when will government give them clearence to test the engine on Tejas so that they can start and then complete in 48 months :roll:

GTRE has a three-fold plan for perfecting the Kaveri for the USAV. First, it will remove the design flaws that were detecting during testing in Russia in 2010-11; then, after ground testing in Bangalore, the Kaveri will undergo a round of confirmatory tests in Russia; finally, it will be fitted on a Tejas fighter for flight tests.


First to rectify design flaw which they noticed while testing in Russia(as is mentioned in that article), will require some serious amount of time and then ground tests and then tests in Russia :(
IMO GoI won't move an inch on clearence for testing on Tejas till all the tests are positive.

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Re: Kaveri & aero-engine discussion

Postby NRao » 26 Dec 2012 16:24

chiragAS wrote:First to rectify design flaw which they noticed while testing in Russia(as is mentioned in that article), will require some serious amount of time and then ground tests and then tests in Russia :(
IMO GoI won't move an inch on clearence for testing on Tejas till all the tests are positive.


THESE flaw rectifications, re-test in Russia and test in a LCA has nothing to do with the IOC/FOC that is being pursued.

These tests are associated with developing an engine for an UAV.

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Re: Kaveri & aero-engine discussion

Postby Singha » 26 Dec 2012 17:09

Narayana Rao wrote:Gurus - Can Kaveri powered AC can be used as a small size Bomber - with limited manuvering capability?


It is a small size bomber they are making..a ucav. Think of the eads ucav.

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Re: Kaveri & aero-engine discussion

Postby SaiK » 26 Dec 2012 18:22

we have been listening to design flaws.. folks in complex engineering like turbines, it is not easy to change things.. this is a serious issue with our design team... that needs support. the team needs to be strengthened with more funds, and replacement of certain designers. their experience is only making products that does not reach specifications. we need to replace them with design and thinkers that exceeds specs... gtre reorg.


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