Kaveri & Aero-Engine: News & Discussion

Raveen · Post by **Raveen** » 08 Sep 2009 22:17

Rahul M wrote:
Raveen wrote:My question is...on a side note basis...why is the IAF specifying what thrust it wants from the LCA engine?
I mean, they are not the designer...they should only be specifying required performance characteristics (top speed for example) and how this is achieved (by aero redesign or by more thrust from a new engine) should be the designer/manufacturer's decision...not IAF
who says they are ?
IAF has specified the performance requirements and the LCA developers realised that they can't achieve it with the kaveri.

secondly, IAF involvement if it happens in a constructive way is a good thing, not one to be scoffed at.

Yes, sir IAF involvement is nothing to be scoffed at
but at the same time I read news reports and links on BR about a 95KN IAF requirement...it just seems counter-intutive that the IAF is specifying the design rather than the performance

Raveen · Post by **Raveen** » 08 Sep 2009 22:19

Kakarat wrote:
nrshah wrote:
I am sorry to disagree. It is about finding the measure to promote the development. Even KMGT does not satisfy the need of IN with respect to destroyers. They require some 22 Mw of power where KMGT currently delivers only 12Mw. In such situation, IN could have very well shelved its hand, like IAF from the project citing that it does not have enough power. But it still ordered around 40 of them along with 42 GTGs. 40 of them is huge figure considering naval ships hardly reach double figure mark as against few hundreds of fighters

Read the article carefully first, A General Electric LM2500 produces 22MW and it is not the requirement for KMGT to produce 22MW. The LM2500 is a derivative of GE CF6-6 aircraft engine, the maximum thrust of CF6-6 is 178 kN

I believe the CF6 is from GE's line of aero engines for commercial/passenger aircraft and hence SIGNIFICANTLY bigger (in terms of both physical dimensions and thrust)
I wonder what kind of thrust the Kaveri would produce at that physical size

vina · Post by **vina** » 08 Sep 2009 22:21

narayanan wrote:Reduces ignition delay by reducing the "rate-limiting" radical-creation step in the reaction, by dumping a lot of Ajaad Lal Kufr (phree radicals) created by sending spark across some suitable gas.

Hmm. Very radical indeed. Maybe they should hire wannab radicals reds like N Ram with molotov cocktails to light the tandoor.

Maybe Bangalore tandoor does not have plasma igniters. This is yet another reason y they should have taken my advice and brought in pucca Ambassador Car mechanics to the Ell-See-Yay team. Very adept with gas welding torch to fix all problems

All the Ambassador welders with gas torches wont be able to fix it if the design is 65KN wet thrust as our diyar Former Karnail turned Jurnailist , Ajai Shook Law seems to imply. Tinkering wont do. It calls for a re design ( we all know that here don't we). But I really cant understand why the GTRE guys speak in riddles via the Shook Laws and in-laws instead of coming out clean with what they have achieved / not achieved.

Frankly, I take Shook Law's numbers with huge dollops of salt. There were reports earlier that the dry thrust was acheived and there was a 2 to 3% shortfall in wet thurst. Dry thrust will be in the 50KN range and A/B thrust will be around 80KN. I cant imagine that anyone could have set the specs in 1998 for 65KN wet thrust.

KrishG · Post by **KrishG** » 08 Sep 2009 22:23

rudresh wrote:if cf 6 generates max thrust of 178 KN and marine version 22 MW

then marine kaveri generates 12 mw that means it gives out about 97 KN
i think 65 KN is the dry thrust of the engine

regards
Rudresh

Believe me, it isn't as simple as school maths here.

Patrick Cusack · Post by **Patrick Cusack** » 08 Sep 2009 22:24

With the weight and thrust limitations for Kaveri perhaps it is an ideal candidate for a naval hydrofoil or hovercraft(larger).

Bheem · Post by **Bheem** » 08 Sep 2009 22:43

Kaveri even at 65kn can be used for AJT-LIFT based on LCA. Point is that will the IAF be interersted to buy without the road being greased?

KrishG · Post by **KrishG** » 08 Sep 2009 22:52

Bheem wrote:Kaveri even at 65kn can be used for AJT-LIFT based on LCA. Point is that will the IAF be interersted to buy without the road being greased?

The specific fuel consumption will be very high due the very-low bypass ratio of Kaveri. Trainers always seem to use comparitively higher-bypass engines as it reduces SFC and very high exhaust is not a requirement for trainers as it is to fighters. I wonder how much weight can GTRE take of a non-afterburning version of Kaveri ??

NRao · Post by **NRao** » 08 Sep 2009 22:55

Those buttons have been flip-flopped. I nearly started a new thread!

The focus - I would hope - is on the new Kaveri (I hope they change the name). Hope it come out way ahead in time.

Rahul M · Post by **Rahul M** » 08 Sep 2009 23:03

krish, he is talking of a LIFT which is almost a full fledged fighter with full offensive capabilities, not a normal trainer.

the current parallel are the Mig-21's of the MOFTU and the hunters of the HOFTU in the past.

nrshah · Post by **nrshah** » 08 Sep 2009 23:22

Read the article carefully first, A General Electric LM2500 produces 22MW and it is not the requirement for KMGT to produce 22MW. The LM2500 is a derivative of GE CF6-6 aircraft engine, the maximum thrust of CF6-6 is 178 kN

May be I did not put it in right way. I did not wanted to say KMGT has to be in 22Mw class. My point is that Navy took interest in the project and is now set to use the Kaveri to propel its corvettes and other patrol ships.

with this kind of support, I don't have any doubt tomorrow, GTRE will be able to develop gas turbine in 22 Mw class also.

Point being that the effort is not total loss.

Ya, efforts are never wasted. U move ahead in learning curve.

Very surprised you make this argument.

IN HAS made the same argument that the IAF made: you yourself stated it: IN will NOT use it for their destroyer because it is under powered.

I only wanted to say it is all about attitude. The fact that KMGT is only 12Mw did not deter IN to think of the area where it fits in. It is not very distant to see new corvettes and patrol ships propelled by KMGT and all those destroyers will have gas turbine generators for electricity.

Encouragement for domestic R & D has to be of this nature. Just beating about bush and claiming we are always in support of Indigenous drive and domestic R & D is not enough.

IN in sharing 25% cost of the project. How much IAF has shared / is willing to share? I hope we will not argue about IAF being end user and should not share cost.

-Nitin

NRao · Post by **NRao** » 09 Sep 2009 02:07

Sure, I think you are right about IN having better attitude (than either IAF or IA). However, in this particular case I am not convinced that the IAF's attitude is misplaced. The IAF relied on a LCA + Kaveri, both of which came in over weight. The IAF has kept the LCA (so the attitude there is OK) and agreed to go with a more suitable engine (IF GTRE can deliver one, the attitude there is Ok too). And, unlike the IN, the IAF is no position to use the less-thrust engine for another machine that is already flying. I think the demands placed on the IAF are a lot more (than the IN) in this term (IN having a lot more ships of varying weights).

The Kaveri seems to be a comedy of errors(?). In the end all the mis-planned errors have turned out to benefit someone/thing. Now, only IF GTRE can deliver on a 95+KN engine (with growth potential please) for the LCA it would be neat.

vina · Post by **vina** » 09 Sep 2009 10:28

Hmm.. our diyar Jurnailist, Ajai Shook-Law says in his blog that he visited Midhani and that work on single crystals and hot zone metallurgy is a "work in progress". Well, they could wait till kingdom come and it will be great if they could come up with the materials.

However, there is the larger kweschun of stratejee (moi YumBeeYea onree no ?

). Why not learn from what the Navy did with the Navy LCA. Now that Nook-Shook deal is done, and we are "near Munna" and on the glide path to Poodledom a la UK stan, why not access the industrial base of Amreeka, Jurmanistan and Frogistan ?. Tap into the supplier base of MTU, Safran, GE, P&W, Rolls, Honeywell ityadi and get high temp materials and ding dongs you want.

Sure, you might have to sign up saying that you cant export the engine without Unkil and associated Poodle' da signature. But so what ?. Expolts like our Chini birathers can come later. That can wait until kingdom comes for Midhani to come up with the required ding dong.

I know that GTRE tied up with SAFRAN for some assemblies. But why not go the who hog, and ask for wide chord fan blades, blisks, and all else, now that kind of trade is open..

arunsrinivasan · Post by **arunsrinivasan** » 09 Sep 2009 11:35

To add to what I said earlier. IMHO, putting my yum bee yea hat on, the issue many people have raised is that GTRE Leadership is not good & that explains most of the problem with Kaveri. My understanding of the leadership problem is that - GTRE is not pushing itself aggressively enough to improve its design, try innovative approaches to solve bottlenecks in technology and capabilities & seems happy to sit on its backside & give excuses. In an ideal world there are million ways to solve this issue. But in a bureaucratic & multi-layered world of government decision making, the choices are limited.

A simple approach with these constraints in mind is to have IAF set up a team to meet with & review GTRE's results at regular intervals (say every few months). IAF need not even have to wield a stick, just ask what they have achieved, what problems they have faced, & how they are trying to solve the problems & bottlenecks, do some brainstorming on solving bottlenecks, also gently highlight what the goals are & review whether the current path will help them achieve the goals. Just the fact that somebody is regularly reviewing can result in huge performance improvements in people / organisations & this can be used effectively by IAF to push GTRE (My yum bee yea experience speaking

). Not sure if is this is enough, but it could make a difference, hopefully big. My 2 cents.

merlin · Post by **merlin** » 09 Sep 2009 12:26

Dileep wrote:Why we call debut flight, maiden flight, suhaag raat etc for the high altitude test? Wasn't it already done an HA test and fail?

This is the first time it will fly in the Il-76 test bed. Hence maiden flight. The earlier HA flight tests were, IIRC, at CIAM and not in the Il-76 test bed. I'm talking about the Kaveri here, not the Kabini.

Rahul M · Post by **Rahul M** » 09 Sep 2009 14:32

earlier test in russia was on a Tu-16 IIRC.

merlin · Post by **merlin** » 09 Sep 2009 16:53

But that test was of the core Kabini, not the full up Kaveri.

Bheem · Post by **Bheem** » 09 Sep 2009 17:36

Al-55 used in IJT is variant of Al-31 used in Su-30MKI. So Kaveri varinats can be used in IJT & AJT if IAF wants but does it want that?

enqyoob · Post by **enqyoob** » 09 Sep 2009 22:55

vinaji: With other kinds of turban on, hiyar eej my suggestion:

Instead of

and ask for

which always leads to yada yada yada, do this through bure 400% halal academic cooberashun. Even Mujahids recognized this long pack. Put instead of sending nanha mujahids to evil de-jeneraat weshtern univerjitiej, pring the rejearch brojects to desi madarssas with desi nanhe mujahids doing em-ess or pee-ech&dee.

Phunding phor said em-ess and pee-ech-dee depends on brohrej in developing this and that. They can go talk to other univerjitiej, get other univerjities to talk to them etc. etc. as long as the work is REALLY PASIC, like:

"Computational and experimental investigation of crack initiation in crystalline solids under cyclic thermal stress."

" A moving -grid computational study of the pressure resistance of a labyrinth seal under multi-dimensional stress in a cylindrical coordinate system"

See? Al Jibbar-eesh. Pasic. Halal. Easy to get advice from the best experts in the field. And if organized pie mullahs with something petween their kaanen than ear-wax and vacuum, this leads directly to improved pressure ratio and T-i-T, and hence to better dry thrust and supercruise.

What is missing is the steady, determined, focused development and reduction to practice of needed technical breakthroughs. Of course where these ARE done, no one believes that they are done.

Instead the desi approach is scatter-brained, to put it mildly. Wait until it is 10 years past the deadline, roll out a sub-par museum piece and call it "meeting specs set in 1920", then announce that the next hope is that some phoren entity is going "collaborate" to develop the next-gen piece, wasting 50 times more money than it would have taken to solve the problem by the above approach, and ending up with something that can't be duplicated because there is no learning, just "MOUs" and IP agreements locking out Indian R&D.

Sorry, but there's the problem I see - any emBeeAys pls exalt that to suitable language and drum it into the Babus.

If phoren technology is 2 b brought into defence R&D, it should be done through madarssas. Not by "asking"

Gaur · Post by **Gaur** » 09 Sep 2009 23:10

^^ I find your posts very educational(specially on kaveri issue) and this wierd form of "phinglish" is somewhat distracting. So could you please refrain from using it in your illuminating posts?:)
But perhaps its only me and the others may very well enjoy it.

Rahul M · Post by **Rahul M** » 09 Sep 2009 23:33

merlin wrote:But that test was of the core Kabini, not the full up Kaveri.

that raises the question, what exact modifications do you need to fit and operate an afterburning engine on a transport that doesn't use AB engines ?

n^3 ji ?

Al-55 used in IJT is variant of Al-31 used in Su-30MKI. So Kaveri varinats can be used in IJT & AJT if IAF wants but does it want that?

IIRC Al-55 is a smaller version of the Al-31 core (i.e engine w/o afterburner). if GTRE can actually develop something like that on time and specs is something we can only guess.

I do believe if they actually come up with something that is comparable to foreign stuff IAF will accept it.

enqyoob · Post by **enqyoob** » 10 Sep 2009 02:01

Strap the whole thing on and hit the "start" button, I suppose. I wouldn't know what is special - anyway it is just hung on the engine pylon on a wing. What happens when there is so much thrust produced, is an interesting question. So it must mean that the aircraft's other engines are at least as powerful, and probabl bigger and heavier too.

The A/B duct is not a heavy item, just adds a bit of length.

Anyway, note that I don't believe that afterburner performance is the only, or even the primary, issue in high-altitude testing.

enqyoob · Post by **enqyoob** » 12 Sep 2009 02:40

See, vina!

Suar-phyrr way to develop injin tech while winning the Babus/Mantris' total approval:

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Buy a couple of these babies, get a couple of injins extra, and turn them into posh restaurants modeled after KFCs in B'lore and maybe Nasik while the injins are taken apart and used for some rejerj. One din a jehadi can toss an halal gas cylinder into the KFC as eet eej written in the Ho Kitab, and that will be that, give the insurance a break and tell them the injins must have been thrown a great distance and lost.

Or, more seriously, keep these in operation, with more than the bare minimum of injin spares. How tough can that be? And LOOK at the interior!!

enqyoob · Post by **enqyoob** » 13 Sep 2009 23:59

Is it possible that engine development is being deliberately understated? That there is an underground factory churning out thousands of super-duper LCA engines with T-i-T of 2500C and pressure ratio of 30 and T/W of 11?

Nice rumor to start, but I cannot find any shred of evidence to hang it on. Maybe the awards are a giveaway?

Gaur · Post by **Gaur** » 21 Sep 2009 23:10

I had asked this question in the newbie forum but got no answer. So perhaps this is more apt forum to ask this:
What are the effects of low bypass ratio for a turbofan engine like Kaveri?
High fuel consumption comes to mind.
Does it also increase the IR signature of the exhaust?
What are the other degrading effects?

A Sharma · Post by **A Sharma** » 24 Sep 2009 19:04

DRDO Tech Focus on Gas Turbine Research

Dilbu · Post by **Dilbu** » 26 Sep 2009 02:41

Inside DRDO's Kaveri Jet Engine
Photos from Live Fist

SriniY · Post by **SriniY** » 26 Sep 2009 03:25

Interesting that the livefist article mentions a bypass ratio of 0.2 - 0.24. My understanding was that it was between 0.16-0.18 based on a lot of posts in this thread. Was the Kaveri slightly modified to accomodate a higher bypass ratio ?

NRao · Post by **NRao** » 26 Sep 2009 03:33

Dilbu wrote:Inside DRDO's Kaveri Jet Engine
Photos from Live Fist

http://2.bp.blogspot.com/_o_no4M2xEPY/S ... 748467.jpg

@ 81 Kn and T/w @ 7.8, ways to go.

shetty · Post by **shetty** » 27 Sep 2009 20:58

Shiv Aroor's data looks to be entirely based on the Tech Focus issue posted earlier by A Sharma, including the photos and the summary.

Interestingly, the Tech Focus pegs the Marine Kaveri output at 15MW instead of 12MW.

abhishekgoel · Post by **abhishekgoel** » 06 Oct 2009 17:48

Any updates on the testing results of the Engine.

SaiK · Post by **SaiK** » 30 Oct 2009 20:30

http://timesofindia.indiatimes.com/indi ... 181231.cms $100 billion market over the next 10 years.. plans to spend more than $30 billion over the next five years to upgrade its defences.

nothing wrong in asking for couple of billion $$s for Kaveri.

karthik · Post by **karthik** » 08 Nov 2009 00:07

I have been searching for the High Altitude test results of the Kaveri which was due in Russia last month but cant find anything on BR. Can anyone update me on the test results, Any good news so far?

SaiK · Post by **SaiK** » 08 Nov 2009 03:15

if we have already spent 3000 crores for K, and still expecting to spend more, why not spend another 100 odd crore more high altitude test facility.. I am sure after Kaveri, there is more engines/versions we might build, especially enhanced ones for MCA, FGFA may be too interested. n number of possibilities.

karthik · Post by **karthik** » 26 Nov 2009 17:40

SaiK wrote:if we have already spent 3000 crores for K, and still expecting to spend more, why not spend another 100 odd crore more high altitude test facility.. I am sure after Kaveri, there is more engines/versions we might build, especially enhanced ones for MCA, FGFA may be too interested. n number of possibilities.

Actually i read in an article that building an High altitude facility would cost atleast 300 to 400 crores. I guess much depends on the success of the Kaveri for the government to take it seriously enough.

enqyoob · Post by **enqyoob** » 27 Nov 2009 04:26

$100M? For an engine test cell capable of going down to the pressure at 20km? That's outrageous. It must be $10M cost and $90M baksheesh. They could take the 3m diameter spare water pipes lying around at the Veeranam Water Supply Project inside the IITC front gates, and use them for the facility walls. Those must cost a solid $1,700,000 crores by now because they have been there since 1975.

shiv · Post by **shiv** » 27 Nov 2009 07:12

enqyoob wrote:$100M? For an engine test cell capable of going down to the pressure at 20km?

If you take a human and cover his mouth and nose with duct tape, you can simulate the air pressure at 60 km. If you put his head in a freezer you can simulate the temperature conditions as well.

I suppose you could put a jet engine in a pipe and seal the front end except for a couple of drinking straws and let the engine do some work sucking air and simulating the altitude hain?

enqyoob · Post by **enqyoob** » 27 Nov 2009 07:35

The things to simulate at high altitude seem to be (a) low pressure and (b) low temperature. The former needs only a powerful pump to suck out the air, but the latter may require a hefty heat exhanger (A-1 Dasaprakash ice-cream machine) to take the temperature down to 217K. I guess the critical condition is high angle of attack, low velocity, at high altitude so that the engine has to suck in low-pressure, low-density air.

Point is, the pressure difference between outside and inside is less than 1 atmosphere - how tough can this be to build? Water pipes are stressed to be leakproof at 120 psi, which is like 8 atmospheres.

In addition, you need valves, some honeycomb, acoustic foam, thrust measuring load cells, some cranes to hoist the engine, all those cool orange tubes and wires, some thermocouples, voltmeters, a couple of good pressure / vacuum gauges, some Pitot tubes (must be a few used L/Airboos models lying around), and for good measure, some accelerometers so you get some warning before the blades go flying, a nifty rotating red light outside the door, a couple of videocameras, an HD video screen, and some nice chairs to sit and watch Test cricket on the monitors.

$100M for that?

shiv · Post by **shiv** » 27 Nov 2009 09:05

Wouldn't the engine itself suck out that air and lower the pressure if you merely narrowed the inlet so much that the airflow coming into the chamber housing the engine inlet is less than that "demanded" by the engine?

negi · Post by **negi** » 27 Nov 2009 09:35

^ I don't think it simulates the high altitude low pressure condition for the pressure in question is atmospheric pressure measured at the blade surface for this value will not change by constricting the inlet ; however I think by constricting the airflow one might be able to simulate the high AoA operating requirement (I might be wrong here).

A more easier way to simulate high AoA operation might be by inclining the engine at an angle wrt to horizontal inside a wind tunnel and then ignite the engine.

SriniY · Post by **SriniY** » 27 Nov 2009 09:36

^^ Where is it mentioned that it a test facility would cost $100 mil. Just asking out of curiosity, could not find a source in the previous page