Kaveri & Aero-Engine: News & Discussion

Neshant · Post by **Neshant** » 17 Jun 2008 22:51

would not holes just weaken a structure.

Anujan · Post by **Anujan** » 17 Jun 2008 23:04

Neshant wrote:would not holes just weaken a structure.

No, depends on many factors. (a) Depends on the direction of stress. Imagine a rod and a cylinder, along the longitudinal axis, they have the same strength this is not true along the perpendicular axis. Similarly, I would expect the blades to undergo stress in an axis parallel to the holes and not perpendicular to the holes. So the holes do not compromise on the strength much.
(b) Materials have very different properties at higher temperatures than lower temperatures. Usually their tensile strength and bulk modulus is higher at lower temperatures (you can imagine them "softening" at high temperatures. This is not exactly the case, the crystal bonds weaken at higher temperatures, which makes it easy for them to snap). If for example the holes compromise strength by 5% but keep the temperature of the blade down by say 25%, it might be well worth drilling holes.

This hole business has an analog in conventional things like knives and swords. If, for example you look at knives meant for stabbing, there is a longitudinal groove in them that make them lighter without compromising strength (take our very own Kukri for example. The groove does not weaken the knife). Knives meant for slashing on the other hand dont have the grooves.

SaiK · Post by **SaiK** » 17 Jun 2008 23:27

following the lines of spinster's ideas above[added later section], wonder if we could avoid drilling by the crystal growth over say stent like tubes arranged in the pattern of the desired holes required, part of the jig.

bala · Post by **bala** » 17 Jun 2008 23:37

Another important point is that each blade is different and has slightly differing curvature. The blades are numbered and inserted in order for the final assembly. Besides temperature gradients, the blades are also subjected to pressure gradients.

I hope GTRE has also mastered high pressure/temp hoses that are used for connecting auxilliary systems. This is one area where major engine failures occur.

John Snow · Post by **John Snow** » 17 Jun 2008 23:49

Neshant wrote:would not holes just weaken a structure.

As long as the dia to pitch is maintained with in tearing and shear stresses its ok.
since the blade is deflecting the jet stream (on a curved surface) you will have mostly torque (torision stress) some bending stress nad couple ( the blade it self is fixed in one end and free on one end hence analogus to a contilever.

also the hole are in varying thickness there fore they should not distrub the static balance (of mass) as it may cause undue vibration and force rotating in excess of 30,000 rpm (at minimum)

SaiK · Post by **SaiK** » 18 Jun 2008 05:14

I am thinking GTRE would jump to BLISKs.

btw, http://www.manufacturingtalk.com/news/nvi/nvi102.html

Single Crystal with BLISK assemblies!!!

http://www.pilotfriend.com/aero_engines ... istory.htm

asbchakri · Post by **asbchakri** » 18 Jul 2008 09:37

Guys wasnt SNECMA awarded a contract in Feb 2006 to help the Kaveri Engine programme. I just want to know in which areas were they supposed to help and what is the status of that. I havent heard much on that area.

K Mehta · Post by **K Mehta** » 18 Jul 2008 15:10

x-posting from lca thread
Modified Kaveri Engine to Propel Indian Navy Ships
The Gas Turbine Research Establishment, Bangalore of Defence Research and Development Organisation which has been indigenously developing Kaveri engine for propelling the Indian Light Combat Aircraft (Tejas), has now come up with a modified marine version, as a spin off during research, to develop shaft power for propelling Indian Naval ship.

Using the core of the Kaveri engine, the scientists of GTRE have added Low Pressure Compressor & Turbine as a gas generator and designed a Free Power Turbine to generate shaft Power for the maritime application. The Kaveri Marine Gas Turbine (KMGT) as it has been named has been transported to Naval Dock Yard, Vishakapatnam and installed on to the Marine Gas Turbine test bed which is an Indian Navy Facility capable of testing the Gas Turbines upto 25 MW of shaft power through a reduction gearbox and a water brake dynamometer.

The Indian Navy has been involved in the development of the engine and participated and supporting the testing phase.

The engine has been tested to its potential of 12 MW at ISA SL 35°C condition which is the requirement of Indian Navy for propelling the SNF (Rajput) class of ships. This engine has been demonstrated to the Prime Minister Dr Manmohan Singh and others including the Scientific Advisor to Raksha Mantri Shri M. Natarajan, Vice Admiral B.S.Randhawa, Dr. D.Banerjee, CC (R&D).

With this development, India will become self-reliant in the technology of gas turbines for ship propulsion. This will put India in the elite club of Marine Gas Turbine designers e.g., USA, Russia, UK and Ukraine.

K Mehta · Post by **K Mehta** » 18 Jul 2008 15:14

The success of KMGT would have interesting implications.
Question to gurus:
IF the KMGT succeeds, and the Kaveri for LCA doesnt, but spawns a number of marine engines which would power IN ships, would the investment made in it be worthwhile?
I agree that it would have failed the LCA programme but one of the main purposes was to create engine expertize in India, which it would have served.
Again Navy takes the lead in developing indigenous products.

Sona R · Post by **Sona R** » 18 Jul 2008 16:06

We can seek help of Rolls Royce in sorting out kaveri engine problem.

At present it is heavily dependent on civil aviation sector and it is outbid in military engine sector thanks to american armtwisting .

why not to rope rolls royce and solve the kaveri engine problem

neerajb · Post by **neerajb** » 23 Jul 2008 11:10

Wikipedia says:

Thrust:

Military thrust (throttled):11,687 lbf (52.0 kN)
Full afterburner:18,210 lbf (81.0 kN) [Goal: 20,200 lbf (90.0 kN)]

http://en.wikipedia.org/wiki/GTRE_GTX-35VS_Kaveri

After going through all the previous posts, it seems like the single crystal blades for the turbine are the stumbling block. But looking at the thrust figures, it is clear that the core part is working just fine and delievering what it was designed to do. Afterburner is the weak link here. In my opinion afterburner design should not be that difficult taking into consideration that GTRE successfully completed the core part.

Cheers....

Singha · Post by **Singha** » 23 Jul 2008 11:37

fanboys tend to brag about their drilled brembo disc brakes too.

chetak · Post by **chetak** » 23 Jul 2008 14:09

K Mehta wrote:The success of KMGT would have interesting implications.
Question to gurus:
IF the KMGT succeeds, and the Kaveri for LCA doesnt, but spawns a number of marine engines which would power IN ships, would the investment made in it be worthwhile?
I agree that it would have failed the LCA programme but one of the main purposes was to create engine expertize in India, which it would have served.
Again Navy takes the lead in developing indigenous products.

HAL Engine Division may have considerable LM 2500 expertise.
They also have very considerable design expertise. 2+2 = .........
Sadly, the Kaveri does not seem to have too much growth potential so spawning
a number of marine GT types for different classes of ships is looking dim.
DRDO will always propose a " Don't raise the bridge but lower the river " type of solution.
We can still hope for the best.
The Navy may prefer to have one robust and dependable engine that it can use in different types of ships by using 1,2 or 4 numbers of GTs on each vessel.
Some of the very fast patrol vessels made by Goa shipyard may accept this GT without
too much of redesign.
There is good potential for use as a turbo generator for disaster management, floating dry docks etc.Good and compact design may make it air transportable. The power to weight ratio will be much better than a comparable DG considering the amount of electricity that can be produced.
Recovered exhaust heat may help in a small desalination plant.

jahaju · Post by **jahaju** » 24 Jul 2008 23:54

http://forums.bharat-rakshak.com/viewto ... 09#p515909

Dabhol Power Plant-
Sources said the gas turbine 2A failed in January after 2,841 firing hours and failure of the second turbine 2B had occured in January last year after 8,801 firing hours. A third major failure could have also taken place but was fortunately averted. During borescopic inspection on June 23, 2008, cracks were detected in compressor stage 15 static vane (S15) of gas turbine 3B after 5,248 hours of firing. GE has advised opening of casing leading to shutdown of about 45 days.

There are also frequent failure in liners, TPs and nozzles. In view of failure, GE has advised preventive borescopic inspection of each machine at an interval of 1,000 hours.

same company parentage, but with vastly different results.

vina · Post by **vina** » 04 Aug 2008 13:21

Hmm. Looks like it is going to be Safran /Snemca.

French Firm to Help Develop Kaveri

The article talks about the French pitching in with the M88 Eco core (from the M88-3). I guess it would be a scaled core from the M88-3 if it needs to get between 25K and 30K lbs thrust that the IAF wants. But dang..Here goes another instance of indian money going to develop a foreign system. The downside is that the GTRE wont get any design knowledge on designing a core. Something better than nothing I guess.

Singha · Post by **Singha** » 04 Aug 2008 13:46

its better than letting GTRE play around for another 5 yrs and then telling us it aint gonna happen.

the french surely will not transfer all their design data but some amt of diffusion will take place
if gtre/goi is interested in developing manpower.

Drevin · Post by **Drevin** » 04 Aug 2008 14:13

vina isn't the eco term applicable to the m88-2. First time I am hearing a M88-3eco. Plz clarify if you have extra info.

And if the gurus confirm this news is true then serious implications for the mrca as well i suppose.

vishwakarmaa · Post by **vishwakarmaa** » 04 Aug 2008 18:22

vina wrote: The article talks about the French pitching in with the M88 Eco core (from the M88-3). I guess it would be a scaled core from the M88-3 if it needs to get between 25K and 30K lbs thrust that the IAF wants. But dang..Here goes another instance of indian money going to develop a foreign system. The downside is that the GTRE wont get any design knowledge on designing a core. Something better than nothing I guess.

When we have such attitude towards our scientists, that what they can give us in return - "something better than nothing".

GoI doesn't have ready to pay mere $2,000 a month to Indian scientists and spend $1lk on world class facilities and project management training, but they are ready to dole out $1 billion to foreign suppliers so that they can pay 20 times to their scientists.

Mere a case of corruption. Nothing more.

We have world-class scientists in metallurgy sitting on their asses in this country but problem is with GoI, because these people are not even in GTRE team.

Solution is to invite correct people into GTRE team and more important is, monitor the project through a professional private industry body.

GoI is taking a wrong route.

vishwakarmaa · Post by **vishwakarmaa** » 04 Aug 2008 18:30

This import of "help" from outside will solve the problem with Kaveri. Oh, maybe. But, it will not solve the problems with GTRE.

They might build this LCA engine eventually, but main root of the problem still remains there. And that problem is, "structure" of GTRE and caste system.

Instead of dealing with this, as usual Indian babus are focusing on short-term gains, but not solving real problem.

After 15 years, during MRCA project, they will say - "oh, we don;t have time. We should have dealt with this poor-class manpower problem during LCA. Now, we should goto americans to buy X-ABC engine as a gap-filling measure"

History is repeating.

SaiK · Post by **SaiK** » 04 Aug 2008 20:48

this is like mig-29 k order., for the french. if we want to improve kaveri, it has to be gtre alone. else, forget about it.

why not directly use f414 or ef200 per our specs, and get the damn apis and precision setup details, so that we at least have that capability and maturity established.

Sri Harsha · Post by **Sri Harsha** » 04 Aug 2008 22:58

Exactly, why waste money on below powered engine which IAF is not going to accept.

Unless this engine can produce 100Kn of trust as required by IAF. Which is not certain. OR
Unless it can be used for MCA, which I doubt it, by the time MCA evolves we would require much higher trust (even for twin engine MCA).

shetty · Post by **shetty** » 05 Aug 2008 02:39

What is this for?

India's gas turbine research establishment will partner French company Snecma SA to build engines for Tejas, the country's light combat aircraft, after efforts by the defence lab to develop an engine on its own faltered.

And what is this for?

Meanwhile, the Aeronautical Development Agency, the aeroplane design lab of DRDO, has invited General Electric and Eurojet Turbo GmbH, a German engine maker in which Rolls-Royce has a stake, for higher-powered engines that would be modified for the Indian fighter, but has not settled on the vendor. IAF has insisted new planes other than the initial requirement of 48 Tejas fighters should have a higher-powered engine.

Raj Malhotra · Post by **Raj Malhotra** » 05 Aug 2008 03:42

I think that long time ago there was some paper talk of M88-4 or M88-2K engine of 110kn. Can this be its revival???????

DUBAI '95 - SNECMA/S KOREA DISCUSS M88 FOR KTX-II.

345 words
22 November 1995
Flight International
10
English

(SNECMA IS PUSHING a derivative of its M88 engine as the powerplant for installation in South Korea's KTX-II advanced jet trainer/light-fighter project, as well as pursuing an increased power variant for a re-engined version of the French Dassault Mirage 2000.

The M88 is a 50kN dry-80kN with reheat (11,000-18,000lb)-class turbofan whose only application is the Dassault Rafale, but Snecma chairman Bernard Dufour says that it is "just the start of a family of engines".

The company is already in talks with South Korea to offer the M88-2K, based on a proposed non-afterburning variant of the M88, the 50kN M88-2S.

Alongside projecting a family of "dry" M88s, Snecma is also looking at developing the 110kN M884. This project is at the preliminary design stage, but is aimed at eventually replacing the M53K in the Mirage 2000.

Dufour says that Snecma has begun studies into the eventual re-engineing of the Mirage 2000-5, whose single M53 engine would be replaced by an M88. The company is already looking at uprated versions of the M88 for projected higher-weight versions of the Rafale - the M88-3 with a thrust of 90kN, and the M88-4 with 110kN - and he sees these as being suitable for the Mirage 2000.

"I don't see why the [re-engined] Mirage 2000 should not be in production in ten years' time - the delta planform still seems to be the best, and there's nothing very new in airframes," Dufour says.

The French company has already proposed the engine to Saab as a potential replacement for the Volvo Aero Engines RM-12 (General Electric F-404) in the JAS39 Gripen, but Dufour says that the marketing tie-up between Saab and British Aerospace for the Gripen has "diminished" the chances of such a substitution being made.

He holds out more hope of his company selling the M88 - possibly in a non-afterburning "S" or "dry" form to South Korea

asbchakri · Post by **asbchakri** » 05 Aug 2008 08:47

shetty wrote:What is this for?

India's gas turbine research establishment will partner French company Snecma SA to build engines for Tejas, the country's light combat aircraft, after efforts by the defence lab to develop an engine on its own faltered.

This is for the solution of issues for Kaveri engine or a complete new engine co-Developed by GTRE a nd SNECMA with probably inputs from Kaveri engine development from our side

shetty wrote:What is this for?

Meanwhile, the Aeronautical Development Agency, the aeroplane design lab of DRDO, has invited General Electric and Eurojet Turbo GmbH, a German engine maker in which Rolls-Royce has a stake, for higher-powered engines that would be modified for the Indian fighter, but has not settled on the vendor. IAF has insisted new planes other than the initial requirement of 48 Tejas fighters should have a higher-powered engine.

This is for the further batch, after first 48 with GE engines, of the LCA

Singha · Post by **Singha** » 05 Aug 2008 10:33

they are talking of the core from snecma. the compressor, afterburner and fadec from kaveri.
as we heard the afterburner was also lacking in some 10% of the desired peak thrust so snecma
expertise will be sought there too. safran & hispano suiza will be roped in for sure. and manufacture
of high quality compressor blades is also an issue...with some $$ we could buy the single crystal
blade tech or blisk tech via snecma's contacts in industry.

there is a big gap between a prototype working engine & a manufacturable and reliable engine
so this collab must cover that gap also to make kaveri a USEFUL PRODUCT.

after that, a derated version for AJTs, UCAVs and further scaling up, enhancements would be
feasible if we play cards right and improve human resources.

GTRE needs to be cleaned up and perhaps put under control of NAL or ADA. major new capex
investments need to be ploughed in and recruitment of bright people on high contract payscales
done. by declaring it as a Instt of national importance (like barc, tifr, iisc..) some scope could
emerge to work around govt payscales. and such instts are exempt from reservation policies.

Arya Sumantra · Post by **Arya Sumantra** » 05 Aug 2008 14:55

Singha wrote:GTRE needs to be cleaned up and perhaps put under control of NAL or ADA.

How about starting with banning the unions in defence PSUs because national security is at stake ? Besides with the Left out of coalition, Government was anyways planning Labour reforms.

Singha wrote:with some $$ we could buy the single crystal
blade tech or blisk tech via snecma's contacts in industry.

No one would part with this. Let's start with first step, local manufacture in collaboration first.

Found an interesting comment on youtube video of Su24, apparently Russia started making jet engines by reverse engineering a Rolls Royce engine sold under license to them for Mig15 and ended up violating the agreement with british.

Singha · Post by **Singha** » 05 Aug 2008 15:24

yes I was talking of local manufacture with foreign help. whoever supplies the
engines for 126 MRCA is going to be a in co-operative mood imo. a guaranteed
stream of revenue on 100s of engines over a 40 yr period.

Russia was supposed to give us some tech under mki project but pulled the rug
as usual

rahulg · Post by **rahulg** » 05 Aug 2008 16:38

Regarding Single Crystal Blade Tech, can't we just get the info from the patents filed, like US Patent 5756225 Single crystal oxide turbine blades

Arya Sumantra · Post by **Arya Sumantra** » 05 Aug 2008 17:22

rahulg wrote:Regarding Single Crystal Blade Tech, can't we just get the info from the patents filed, like US Patent 5756225 Single crystal oxide turbine blades

Easier said than done. While useful, patents still leave out a lot of information and give info in terms of broad ranges (of temperature for example). Also the patents attempt to be general and not too specific in giving out parameters. What goes into the actual product is often a small subset of entire domain protected by a patent.

SaiK · Post by **SaiK** » 05 Aug 2008 23:09

I suggest these changes for GTRE:-

Stakeholders:-

Tatas or L&T- 20%
ISRO - 40%
GTRE - 20%
HAL - 10%
ADA- 10%

Arya Sumantra · Post by **Arya Sumantra** » 05 Aug 2008 23:20

SaiK wrote:ISRO - 40%

Why ISRO? Rocket & Cryogenic engines are an entirely different ball game.

SaiK · Post by **SaiK** » 06 Aug 2008 07:24

per last year note:-

Defence Ministry has told the committee that proposals were under study for co-development of F-125 engines with US Honeywell .

"HAL should be allowed to function on the lines of ISRO and Indo-Russian Brahmos cruise missile project"

"HAL should be totally independent from DRDO. It should be re-structured so as to make it an autonomous research and development organisation,"

high-level committee be appointed to work out the re-structuring of HAL

armed forces should have permanent representation in the HAL board

--►

but why f-125?
http://www.honeywell.com/sites/portal?s ... A6B0&sel=4

sunilUpa · Post by **sunilUpa** » 06 Aug 2008 07:54

SaiK wrote:I suggest these changes for GTRE:-

Stakeholders:-

Tatas or L&T- 20%
ISRO - 40%
GTRE - 20%
HAL - 10%
ADA- 10%

The result will be same as that of Daimler-Chrysler marriage...Daimler quality went down the tube.

venkat_r · Post by **venkat_r** » 06 Aug 2008 10:07

I think it is imperative to get a working model of engine and protect the knowledge already learned, rather than loosing all that in search of a perfect one ourselves. For now this is probably the best solution. There has to be a lot more investment which is already being fought tooth and nail to get some good results. This itself is the shortcut, have to learn by working on each piece ourselves, but might not be able to work on each piece ourselves at the same time.

Also like Singha suggested, some sectors should have kind of a "Over ride" on payments, salaries, hire and fire rules for a period of Say "5, 10 or 15" years and only select rules apply. This is until private sector comes up to an acceptable level of knowledge.

Raj Malhotra · Post by **Raj Malhotra** » 06 Aug 2008 12:39

SaiK wrote:I suggest these changes for GTRE:-

Stakeholders:-

Tatas or L&T- 20%
ISRO - 40%
GTRE - 20%
HAL - 10%
ADA- 10%

Don't forget Triveni and BHEL who have the only manufacturing experience with Turbines. Though even Reliance would be good, they will get talent from all over the world and then also use Kaveri derivatives in their projects as indutrial engines

Arya Sumantra · Post by **Arya Sumantra** » 06 Aug 2008 19:59

Split the work of GTRE engine into smaller projects: (1) Engineering projects (2) Applied research projects (3) Fundamental research projects
Engineering projects for components to be made with existing/established industrial knowhow. Execute with private industrial collaborators.
Applied research projects for work to be done in bringing lab-level technologies(demonstrated in India/Overseas) to production floor
Fundamental research projects: Split between labs like DMRL and PhD students at Postgraduate research institutions. These could include all the research for new materials and make use of metallurgical experts elsewhere in the country outside the GTRE/DRDO.

Baljeet · Post by **Baljeet** » 06 Aug 2008 20:28

SaiK wrote: but why f-125?

Saik
High powered comittee and their family members in this searing hot weather can take a trip to US on Indian Taxpayer expense, do some shopping.

F-125 only produces thrust of 41.1Kn that is when uprated-boosted. IAF requirement is of 90Kn IIRC. Don't know how does this engine fits in this requirement. But again strange things happen here.

Sontu · Post by **Sontu** » 07 Aug 2008 00:10

Baljeet,

Regarding why F125 ?

1. Alternate option for AL-55I, which as of now planned to be used for HJT-36, as India may opt for F-18 option in MMRCA contract so ,it will be easy for IAF to train indian pilots on HJT-36 with an American engine.

2. We have seen the fate and result of PRC's indegenous fighter project F-CK-1.which used F125.
From wiki...http://en.wikipedia.org/wiki/AIDC_F-CK-1_Ching-kuo
says...
"There is also speculation that the use of weaker engines was due to political rather than technical reasons, namely that the US did not want to see Taiwan provoke the PRC and thus mandated the IDF to have a "range no greater than the F-5E" and "ground attack capability no greater than the F-16". Regardless of the reason, many people consider the F-CK-1 to be somewhat underpowered, meaning that its performance is not at the same level as other ROCAF fighters (i.e the Block 20 F-16).[citation needed]".

So if at-all F125 is planned to be used for LCA/MCA then it is the begining of a strategy by Powerful people in Politics plus People in Defence arena..to provide the same fate for LCA/MCA..for political reasons and also for strategic reason (to provide IAF engines with less power).

Regards,

SaiK · Post by **SaiK** » 07 Aug 2008 01:46

sunilUpa wrote:
SaiK wrote:I suggest these changes for GTRE:-

Stakeholders:-

Tatas or L&T- 20%
ISRO - 40%
GTRE - 20%
HAL - 10%
ADA- 10%
The result will be same as that of Daimler-Chrysler marriage...Daimler quality went down the tube.

Are you saying Chrysler is GTRE or ISRO? I am sure you wouldn't even think about the later being in that category? May be we are reading into this too much?

Raj Malhotra · Post by **Raj Malhotra** » 12 Aug 2008 17:20

There does not seem to be any other report on Kaveri-M88 JV combination except one report aforesaid. I think whenever the JV is signed it should be broad and cover:-

1. setting up labs for future research

2. Further engine for FGFA/MCA

3. TVC for LCA-MCA

4. Marine engine

5. AJT engine

6. Industrial and power engines

7. Turboprop & Turbo-shaft variants

8. Passenger aircraft and MTA engine variants