AMCA News and Discussions

srai · Post by **srai** » 08 Jul 2015 11:58

IMO, some of the things learned from the LCA experience would be the following:

High-risk indigenous R&D items, like engines, radar, etc., should have a proven "foreign" one for Mk.1 variant. JV should be considered for Mk.2/3 variant. At Mk.1/2/3 MLU, indigenous ones could be integrated (if ready by then). Selected engine should have up to 20kN growth potential.
For those "foreign" backups, have at least two sources, one primary (i.e. Western) and one secondary (i.e. Russian), to overcome any sanctions. Some design feasibility should be performed on the secondary source in case it needs to be integrated when sanctions occur.
An indigenous parallel effort must continue for those "foreign" sourced engines, radars, and other LRUs. They should be fitted-in when ready in future variants or at MLU--gives at least another 15 more years to develop an indigenous one on top of 15 years of R&D from project inception.

Bhaskar_T · Post by **Bhaskar_T** » 08 Jul 2015 14:10

Saurav Jha ‏@SJha1618 - Twin Axis thrust vectoring will be proved on a Kaveri prototype at the bench level before it is ported to the AMCA engine.

Saurav Jha ‏@SJha1618 - Americans are losing out on the AMCA engine effort due to the usual State Department bullshit.

Saurav Jha ‏@SJha1618 - 10 percent of the development cost of the AMCA will come from the military.

Saurav Jha ‏@SJha1618 - The AMCA program will see the development of 8 prototypes. A foreign partner will be needed on the manufacturing side.

PS - Apologies, no sourced mentioned in his tweets. Admins - Let me know if posting unverifiable tweets are not welcome.

Kartik · Post by **Kartik** » 08 Jul 2015 15:41

Not at all..Saurav Jha's tweets are always welcome on BRF. He's undoubtedly the most informed defense reporter in India.

putnanja · Post by **putnanja** » 08 Jul 2015 18:29

shiv wrote:Here's a bet. Call me out if I am wrong.

India is going to get an uprated Eurojet engine for AMChA combat aircraft

Have to agree. They are not going in for another fiasco a la-kaveri. When the Kaveri itself is not fully functional and upto spec, expecting a more powerful version of it to be ready by AMCA timelines is fallacy. Better to go with proven engines (or updated version of existing proven engines) than designing for Kaveri-like engine now, and changing design to suit different engine mid-way.

SaiK · Post by **SaiK** » 08 Jul 2015 19:11

http://drdo.gov.in/drdo/tenders/viewTen ... Micro=4294
Notice the 75/110kN GTRE tender.. it specifically calls for all blisk blades.. now why do they have to reduce their legs for an existing shoe. And someone please explain the 5:1 pressure ratio. tia/

NRao · Post by **NRao** » 08 Jul 2015 19:33

SaiK wrote:http://drdo.gov.in/drdo/tenders/viewTen ... Micro=4294
Notice the 75/110kN GTRE tender.. it specifically calls for all blisk blades.. now why do they have to reduce their legs for an existing shoe. And someone please explain the 5:1 pressure ratio. tia/

So what happened to it?

That tender closed on Apr 28, 2013.

No bites?

NRao · Post by **NRao** » 09 Jul 2015 07:38

I take it that Modi never brought up the 154 FGFAs during his discussion with Putin.

I am even more bullish on the AMCA.

Hobbes · Post by **Hobbes** » 09 Jul 2015 07:54

Bhaskar_T wrote: .....
Saurav Jha ‏@SJha1618 - 10 percent of the development cost of the AMCA will come from the military.

Saurav Jha ‏@SJha1618 - The AMCA program will see the development of 8 prototypes. A foreign partner will be needed on the manufacturing side.

PS - Apologies, no sourced mentioned in his tweets. Admins - Let me know if posting unverifiable tweets are not welcome.

Takeaways:
1. The IAF is on board the AMCA project, hence the financial commitment. AFAIK they made no such commitment for the LCA, unlike the Navy.

2. More importantly, the foreign partner for manufacturing clearly (to me) signifies a move away from HAL to the private sector. The manufacturing will IMO most probably be given to an established Indian private company that has tied up with an experienced foreign aerospace major for partnering on the large scale manufacturing process and provision of ToT on assembly technology. The partner would have to be involved from the prototype stage itself, unless this is outsourced to HAL, which I do not see happening for several reasons.

Hobbes · Post by **Hobbes** » 09 Jul 2015 07:57

NRao wrote:I take it that Modi never brought up the 154 FGFAs during his discussion with Putin.

I am even more bullish on the AMCA.

I wouldn't be too sanguine about that - the F-35 waits in the wings.

Prasad · Post by **Prasad** » 09 Jul 2015 10:36

I am not reading anything on Navy involvement in the AMCA project. Given they are deeply embedded in the LCA, they're not interested in a naval version?

maitya · Post by **maitya** » 09 Jul 2015 11:31

ramana wrote:NRao we both are voting for a new Indian developed engine.. Maitya is going to vell how it can be developed based on Steps 3a and 3b.

Let me bring out a technological challenge to illustrate the issue with advanced manufacturing technology availability in India vis-à-vis it’s impact to any next gen turbofan development initiative. But let me, at the same time, link it to Kaveri programme to illustrate the impact (on unavailability) part a little more vividly.

This is just one aspect, of many technological challenges, that needs solving if we are to graduate to a supercruise-capable-turbofan that is substantially indigenous ... apologies it turned out to be more verbose than I originally intended,
(Also not sure, how will I dwell with other such challenges, if all of them are going to be such verbose - food for thought for me to mull over - any suggestions, pls!!).

Anyway here goes ...

[Problem Desc]
If you refer to this link here (and focus more on Step 3a), the issue at hand is 125-130Kg overweight of Kaveri.
There’re many reasons why it’s overweight, but one of the primary reasons (another primary reason is the heavy 3-stage Fan, which should have been CFRP based etc) is the last 3 stages of the HPC being made of equiaxed Ni-based superalloy INCONEL-718 (called GTM-SU-718, basically a Ni-Cr superalloy, the exact composition of it is in the Kaveri Sticky thread), which has quite high density (8.19gm/cm3), making them quite heavy.

Before I proceed further, pls note manufacturing of equiaxed Ni-Cr superalloy blades and disks are completely within the reach of Indian industry, so not much of any issue here (problem is with joining them together, where LFW and Powder Metallurgy etc comes into picture to enable lighter weight blisks, but that’s for a separate discussion).

This usage of Ni-Cr based superalloy in the last couple of stages of a HPC, is a global phenomenon so Kaveri is actually no exception. This is required, as the stagnation temperature gradient rises quite steeply across the compressor stages (if it doesn’t, you have a problem – this is related to Euler’s Turbine formula, you may want to refer to his post of mine in the Kaveri Sticky thread to have a deeper understanding of it) and quite comfortably crosses the 600deg C mark.

Now since 600deg C is the Ti material limit, the HPC blades will start deforming (given the amount of mechanical/tensile stress it’s subject to) by the time it has crossed the 4th (or maybe even 3rd) HPC stage. So while, you can get away by having Ti-based initial HPC stages, the later ones, require tolerance level in the region of 700-850deg C etc. – something Ni based superalloys could withstand.

But since the temp regime is not >1K deg C etc, there’s no need of any “specially casted” alloys (like DS or SC), SDRE equiaxed (with some double precipitation type of heat treatment etc – details in Kaveri sticky thread) ones would do.

But Kaveri is over-weight, so some other arrangement is required, right?

[Probable Mitigating Solution]
One of the ways to mitigate this is to find some other alloy with comparable Thermal and Physical properties but with lower density (so lower weight, for a given volume of blade-disc geometry).
And Ti-Al (Titanium Aluminide) is just that alloy (with approx. 50% of the density of Ni-Cr alloys at ~4gm/cm3).

So far so good … but if amateurs like us could figure this bit out, why haven’t been the GTRE/MIDHANI folks?

Answer is, it’s not about just figuring it out or even having theoretical understanding of it’s properties and manufacturing processes, but actually possessing the manufacturing machinery and having the required knowledge of applying the required manufacturing processes to, well, manufacture it in an industrial scale.

[Solution Description – EBM and 3D Additive Manufacturing]
Let’s see how it’s done worldwide and who are these industrial houses who have actually declared this capacity publicly (such cutting edge capability possession, are many times kept under wraps for a very long time).
Pls note Ti-Al is notoriously difficult to work with as it has high contraction ratio – this means, using traditional low-wax etc casting methods, the components can become fragile and crack while cooling, if the speed of cooling is not very very tightly controlled (another technology in itself).

The “modern” process of manufacturing Ti-Al based components is done via Electron Beam Melting, absolute cutting edge in Additive Manufacturing sphere – wherein, components are built up, layer-by-layer of metal powder, melted by a powerful electron beam (and each layer is melted to the exact geometry defined by a 3D CAD model – basically a 3D manufacturing technology, if you will).

And this is not just some plain vanilla Electron gun, where beam of electrons are getting accelerated by strong electromagnets – the beams need to be strong enough to support very high melting points (of Ti etc) but also needs be fast and accurate enough to allow multiple melting pools to be maintained simultaneously (required for surface finish, precision etc).
Pls note the deflection electronics for such high degree of beam-control is a cutting-edge technology in itself.

And at the same time it needs to provide a reasonably high productivity so that some-respectable-level of capacity can be obtained from it.
And, as is usual for all such processes, all of these need to happen in high-vacuum, to protect the integrity of the material properties of the component being produced.

Long story short, this is absolute cutting edge in additive manufacturing process …

[Another Angle of the Solution]
Before I proceed further, do note one of the next-gen compressor-blade design goals, is to be able to have a multi-circular arc profile (current Kabini HPC, IIRC, is double-circular arc profile design) – the advantages of which are there in the Kaveri sticky thread in this post.
----------------------------------
(Factoid: GTRE folks in the early 90s actually designed the HPC blades to be multi-circular arc profile. And when they approached a German manufacturer (forgot the name etc), they simply laughed their asses off, when GTRE folks mentioned the volume of such blades to be manufactured – end result, tail-between-legs downhill-skiing and resort to “traditional-but-still-somewhat-cutting-edge” double-circular arc profile based HPC blades.
But you will tons of harrumphgiri stating, “low OPR yaar, no hope with these losers and incompetent designers” etc. )
----------------------------------
Problem is such complex structural profile manufacturing is practically possible with these 3D additive manufacturing processes.

[IP/Commercial Angle of the Solution]
But coming back to the topic, the original question was practical usability of all these wrt reducing the weight of last 3 HPC stages of the Kaveri.

So if Ti-Al is to be used (in those 3 stages) we need somebody to provide us with the relevant technology to do so – search around there’s only one or two companies who possesses this technology today. And one of them is Italy’s Avio (a subsidiary of GE) in a JV mode with Sweden’s Arcam – they use this technology to produce LPT* for the GEnx and GE9X series of engines (for Boeing’s Dreamliner, 747-8 next-gen 777X series etc).
-----------------------------
(*Note: Turbines they are talking of – so the temp, tensile, LCF, creep-propagation etc are multiple degree more stringent there (compared to HPCs). But, if you have noticed above, EBM also means Powder Metallurgy manufacturing capability stuff – aka blade material properties better than cast and comparable to wrought material required for their discs, so in effect blisk manufacturing technique, and thus solving so many other “joining” issues etc – refer to this post of mine in the Kaveri sticky thread, for a glimpse of the dichotomy being talked about here).

So what do you do - go with a begging bowl and asking GE (note Avio Arcam et all are direct subsidiaries, so no point in approaching them individually) to give (like “dey-do”, “dey-do” chanting) this tech. Why would *any* commercial org be so altruistic?

[Conclusion]
Instead a JV between GTRE and GE , tasked to create a Kaveri-II (and with an adequate assured commercial benefit in terms of assured orders etc) can make a business case for GE to have the required EBM setup in India – as they will now have to won the “problem” of “reducing weight of the last 3 HPC stages of Kabini”.

But most probably, even then, GE may not be interested, not until atleast there are multiple such options available worldwide, in a couple of decades time. Instead they can simply employ another completely different technical solution of convective-blade-cooling (something similar employed in Kaveri HPT and LPT) for these HPC stages as well, and in the process, revert them back to pure Ti based ones (like the 1st couple of HPC stages), and save quite a bit, but not fully, of weight (Ti density is 4.43gm/cm3).

As the grand-mullah enquoobuddin-gas-turbini had sermoned, many many many moons back, that there's no easy path in any serious ab-intio turbofan development initiatives (PissBUH).

ramana · Post by **ramana** » 10 Jul 2015 01:29

EBM 3-D mfg is like laser sintering?

ShauryaT · Post by **ShauryaT** » 10 Jul 2015 06:55

Maitya: Thanks for taking the time to elaborate. Will take some time for person like me to to digest it all.

Hobbes · Post by **Hobbes** » 10 Jul 2015 08:16

Saurav Jha's latest:
* MMRCA being curtailed was a huge shot in the arm for the AMCA project.
* Given that AMCA is now a certainty, more Rafales could end up being ordered if Russia doesn't bend on the FGFA.

maitya · Post by **maitya** » 10 Jul 2015 15:55

ramana wrote:EBM 3-D mfg is like laser sintering?

AFAIK, they are similar as with Laser Sintering (or more precisely Direct Metal Laser Sintering, DMLS) a CO2 Laser would be instead of an Electron beam gun in EBM. Both achieve high energy levels in a very narrow beam-width etc.

However in Laser Sintering the components tend to acquire porosity and rough surface finish - both undesirable for blades and disks (of Compressor/Turbines) where surface finish is of paramount interest (including non-porosity and tensile strength levels). EBM has no such "vices" - plus since EBM is normally conducted in a vacuum setting, it helps maintaining their crucial high-strength properties and also prevent oxide and nitride "adulterations".

The other crucial advantage is ability to deflect the electron beam minutely (by changing the strength of electromagnets etc) without moving around the gun itself - much easier to control with much more accuracy (the laser itself had to be moved around).

Of course other stuff like lower power consumption, higher scalability etc also are there.

That's the reason you will find DMLS application examples are very very limited on Ni-superalloys and aerospace-grade Ti alloys etc (not that it's not used for them, but very rarely) - and number of companies having proficiency in DMLS are quite a large number (comparatively).

However another Laser (Nd:YaG) based manufacturing process called LENS (Laser Engineered Net Shaping) is used for Turbofan applications. Don't know what their relative disadvantages are wrt EBM though!!

NRao · Post by **NRao** » 10 Jul 2015 17:54

Do we know what was asked from GE, that the SD rejected?

SaiK · Post by **SaiK** » 11 Jul 2015 19:58

NRao wrote:Do we know what was asked from GE, that the SD rejected?

Joint team force to upgrade F414-INs6 to 110-116kN.

http://www.business-standard.com/articl ... 054_1.html

http://www.geaviation.com/engines/docs/ ... Family.pdf
->
http://www.geaviation.com/engines/docs/ ... hanced.pdf

India was like asking to sleep with their technology.. I think I have repeatedly said this.. we can't beg, steal or borrow this important piece of precision engineering. Forget GE, even the russians or french will not do it.

NRao, you should not be even asking this question and we all should have put GTRE under direct PMO monitoring on this important Kaveri 110kN project.

NRao · Post by **NRao** » 12 Jul 2015 01:39

On the "engine" topic:

http://thediplomat.com/2015/06/an-india-us-tussle-over-technology-transfer/

In addition, working groups were announced to explore cooperation on jet engine technology and aircraft carrier design. Both areas are of immense importance to India but according to reports in the Indian media, the U.S. is reluctant to part with the latest jet engine technology, which New Delhi wants.

India’s Defense Research and Development Organization wants to partner with GE on the latest F-414 engine for the future Tejas Light Combat Aircraft. So far the U.S. side has been reluctant despite the scope of future engine deals which may leave India no choice but to consider an international tender, according to Ajai Shukla, a prominent defense analyst.

U.S. analysts agree that Washington is unlikely to part with cutting-edge technology because that’s what gives its defense industry an edge. The DTTI initiative can start at the lower end to test how the two bureaucracies, private industry and other suppliers connect. “You can’t produce a Lamborghini right away,” one American official told me earlier this year

What was that "cutting-edge technology"?

This lady is NOT right on "for the future Tejas Light Combat Aircraft". The MK-II will use the INS6 engine, which will be manufactured in India - that is a done deal.

The tech that was declined was associated with the EPE engine - expected to be used in the AMCA.

Interestingly, as a result of the tender to be floated India could still wind up with the GE F-414 EPE engine. The tender only widens the field of engine vendors.

NONE of this has anything to do with the "Kaveri" - which to the best of my knowledge exists only in its "core" form. The effort to use that "core" and build around it is a totally different, parallel and an independent effort.

brar_w · Post by **brar_w** » 12 Jul 2015 01:43

The tender will most likely have TOT obligations as part of the deal and IMHO is the absolute best way to go. GE can still lobby the SD for its cause and getting the desired TOT from the companies supporting the Eurojet won't be easy as the Rafale deal has shown.

NRao · Post by **NRao** » 12 Jul 2015 02:53

IMHO, IF others had the same or similar techs as GE, India would not have made an attempt outside a tender. The tech India was seeking was serious enough to make it part of the the def framework, create a special team and request it.

I just do not see that request being part of the tender deal. If GE plays a role and it comes, great.

ramana · Post by **ramana** » 12 Jul 2015 06:28

NRao One very very high up in DRDO said in 1980s, I paraphrase "we do not ask what we want as it tells them where we are lacking. We chose from what they offer."

Has helped India all along.

If you note the WG is non starter. Indian problem is non allocation of funds for whatever reasons under B team govts.

Any way US doesn't make a Lamborghini!!! Corvette is best effort.
NaMo wont do that.

NRao · Post by **NRao** » 12 Jul 2015 07:22

I think India made the engine a part of the Def Framework + DTTI, not the US.

And, it is a good move actually. Just that - from what I am reading - India did not manage expectations. Well ............ Cannot blame them for shooting for the stars.

No matter what, I am still curious to find out what India specifically asked for.

shiv · Post by **shiv** » 24 Jul 2015 09:22

From the IAF Twitter page - AMCA image?

Someone please teach me how to post a screenshot of a twitter post. Where the "begging" icon?

Viv S · Post by **Viv S** » 24 Jul 2015 09:30

shiv wrote:From the IAF Twitter page - AMCA image?

Someone please teach me how to post a screenshot of a twitter post. Where the "begging" icon?

Go to your start menu and type 'Snipping Tool'. New -> Click + Drag -> Save (I'm assuming you're using Vista/7/8).

Quickest uploads through imgur.com. Take just seconds.

Indranil · Post by **Indranil** » 24 Jul 2015 09:31

No. It is the Japanese ATD-X Shinshin

Viv S · Post by **Viv S** » 24 Jul 2015 09:32

That's the Mitsubishi ATD-X mock-up though not the AMCA.

See Here

The original ATD-X mock-up was used for radar cross-section trials that were undertaken in France. This year the flying prototype is slated to be unveiled (Photo: TRDI)

member_24684 · Post by **member_24684** » 24 Jul 2015 09:34

shiv wrote:From the IAF Twitter page - AMCA image?

Someone please teach me how to post a screenshot of a twitter post. Where the "begging" icon?

possibly from Japanese Yahoo Blog posted in early 2007.

One more there is no IAF page in Twitter..those IAF named handles are Fake accounts

shiv · Post by **shiv** » 24 Jul 2015 10:01

SajeevJino wrote:
shiv wrote:From the IAF Twitter page - AMCA image?

Someone please teach me how to post a screenshot of a twitter post. Where the "begging" icon?
possibly from Japanese Yahoo Blog posted in early 2007.

One more there is no IAF page in Twitter..those IAF named handles are Fake accounts

Ah! That sounds closer to the mental image I had of the AMCA program.

The account seems to have been suspended in the last 15 minutes

shiv · Post by **shiv** » 24 Jul 2015 10:06

The page linked below suddenly has a new image. This looks like an IAF page - is it fake?
https://twitter.com/IAF_INDIA

shiv · Post by **shiv** » 24 Jul 2015 10:08

Viv S wrote:
shiv wrote:From the IAF Twitter page - AMCA image?

Someone please teach me how to post a screenshot of a twitter post. Where the "begging" icon?
Go to your start menu and type 'Snipping Tool'. New -> Click + Drag -> Save (I'm assuming you're using Vista/7/8).

Quickest uploads through imgur.com. Take just seconds.

Thanks - but I'm on Ubuntu Linux.

Yagnasri · Post by **Yagnasri** » 24 Jul 2015 10:14

Mango observation - May be the designs will be similar because the stealth requirements impose certain restrictions, shape requirements and parameters on basic design.

Thakur_B · Post by **Thakur_B** » 24 Jul 2015 18:53

shiv wrote:The page linked below suddenly has a new image. This looks like an IAF page - is it fake?
https://twitter.com/IAF_INDIA

Authentic. It's from Aero India.

Viv S · Post by **Viv S** » 24 Jul 2015 19:47

shiv wrote:Ah! That sounds closer to the mental image I had of the AMCA program.

Be honest, its the blue floors and spartan environment that convinced you, right? Very PSU-like. Could pass as Russian.

(One usually expect a Japanese or Western workshop/lab to be very white, perhaps with lots of glass. You know... minimalist uber-looks.)

hanumadu · Post by **hanumadu** » 24 Jul 2015 20:11

shiv wrote:From the IAF Twitter page - AMCA image?

Someone please teach me how to post a screenshot of a twitter post. Where the "begging" icon?

Print screen and crop the image. Dont know a better way.

http://askubuntu.com/questions/114407/h ... age-viewer

shiv · Post by **shiv** » 24 Jul 2015 20:24

hanumadu wrote:
shiv wrote:From the IAF Twitter page - AMCA image?

Someone please teach me how to post a screenshot of a twitter post. Where the "begging" icon?
Print screen and crop the image. Dont know a better way.

http://askubuntu.com/questions/114407/h ... age-viewer

Yeah - that is what I do - but that involves uploading to my photobucket account. I was looking for a lazy way of posting the entire Twitter post and image.

shiv · Post by **shiv** » 24 Jul 2015 20:28

Viv S wrote: Be honest, its the blue floors and spartan environment that convinced you, right?

Nothing convincing. Just very very suspicious - and on the IAF Twitter site. It is the IAF Twiiter account alright and within minutes of my Tweet they changed the image to the one below
https://twitter.com/IAF_INDIA/status/624451351980838912

hanumadu · Post by **hanumadu** » 24 Jul 2015 20:52

shiv wrote:
hanumadu wrote:
Print screen and crop the image. Dont know a better way.

http://askubuntu.com/questions/114407/h ... age-viewer
Yeah - that is what I do - but that involves uploading to my photobucket account. I was looking for a lazy way of posting the entire Twitter post and image.

I think that would rank high in the wish list of many twitteratis. Twitter should provide an option to save the tweet as an image.

sankum · Post by **sankum** » 25 Jul 2015 14:20

https://twitter.com/writetake

sivab · Post by **sivab** » 25 Jul 2015 18:09

sankum wrote:https://twitter.com/writetake

Am I reading this slide right? Empty weight is 18T!!! & internal fuel is 9.5T!!! Both those numbers are very close to SU30MKI. Loaded weight will be 27.5T and MTOW will be 34T? Thats a heavy fighter, yet first line says < 25T, medium weight. Weird.

deejay · Post by **deejay** » 25 Jul 2015 18:23

^^^ That fuel figure also does not match with 02 hrs endurance.