Kaveri & Aero-Engine: News & Discussion

[Rakesh]

pravula sir, Admiral and maitya sir, that's what I have been trying to convey. Stick to the expected performance achievable for Kaveri and design a/c with those specs. It could be K9 or even K8, so be it. It won't be a world beater, but it will fly and teach us the art of making an engine at commercial scale and perfecting it. No amount of R&D will be adequate if we don't integrate and fly those engines in our a/c. We could get to K9+, K10, etc., when we reach the maturity level.

Provide the funding and then the above will surely work. GOI has to provide the funding. The GOI is the one that needs convincing.

[Rakesh]

https://x.com/VinodDX9/status/1871420658909122826 ---> The news regarding the delayed delivery of the GE F404 is nothing shocking or unexpected, actually! Such will be inevitable if you don't develop your own. Today it's F404, but tomorrow could be the same for the F414. Marut to Tejas - we are in a loop!

[Prasad]

Kaveri engine approved for inflight testing: A breakthrough in Indian aerospace

...
India's Gas Turbine Research Establishment (GTRE), part of the Defence Research and Development Organisation (DRDO), announced the Kaveri engine's clearance for inflight testing on December 23, 2024.

Just one statement from us on IAH on youtube that gtre told us way back in 2017 that kaveri had passed safran's audit and was cleared for flight trials has resulted in god knows how many articles in the last one week


As for CMCs, the nozzle flaps are the first place they'll be used. Next are C/SiC or SiC/SiC (forgot which but must be the latter) engine shrouds. It was a 2 yr program I think and must be ready by now. Same with the PMC bypass duct. Rotating parts will take time and we still don't have gamma Ti-Al either. We could get that from the frenchies (they use it on leap engines). So DS blades it is until either of them get to required maturity.

[Baikul]

Does anyone else wonder about the timing of some of these ‘news reports’ or rehashed ‘exclusives’?

The fighter engine purchase and acquisition program is in trouble - once again. People starting to once again question the competence of those in charge.

And then all of a sudden we have a report about an ‘important milestone’ for the domestic Kaveri engine! Except that it’s not new, but leave that aside for a moment.

A few frayed nerves are soothed and the naysayers quiet down, the discourse moves elsewhere.

I’m afraid this is what it now looks like to me.

[basant]

Provide the funding and then the above will surely work. GOI has to provide the funding. The GOI is the one that needs convincing.

Please allow me to conclude my thoughts and this will be my last post on this topic. I do not wish to absolve the GoI for the insufficient funding of the Kaveri project. That said, in my opinion, the real issue lies neither with the GoI nor with the so-called bean counters (whoever they may be). The GoI, regardless of the party in power, has consistently invested heavily in R&D once convinced. These include: (a) ISRO’s communication and dual-use/spy satellites, the Moon orbiter, the Moon rover, the Mars orbiter, etc.; (b) the Arjun MBT, ALH (including the Shakti engine), ATAGS, various radars, rockets, etc., for the Army; (c) ATV (nuclear sub), shipbuilding, NUH, NLCA (including the SBTF), etc., for the Navy; and (d) countless missiles, helicopters, EW systems, AEW, AESA radars, LCA Mk1/2, trainers, etc., for the Air Force. In fact, some of the most innovative products were only revealed after testing (e.g., ASAT) and I have not included the nuclear programmes, BMD programme and strategic missiles!

If that is the case, why doesn’t Kaveri receive the attention it deserves? The answer is simple: the IAF and the IN. I am yet to find a single IAF chief who strongly advocated for an indigenous engine to make India really self-sufficient in aircraft propulsion. On the other hand, the IAF sought to exclude Russian aircraft to avoid "over-reliance on Russia", and to promote `diversity' in their fighter fleet. To that end, they initiated the MMRCA program while fully being aware that the budget would be inadequate, and failed to have a contingency plan despite a decade-long process! Around the same time, they sought to equip many squadrons with Indian fighters powered by an engine from a country that imposed sanctions on us on that very programme! Was that engine an inevitable choice? No, we could have used an alternative engine from France or even shifted to a Russian engine, as these two countries stood by us during our crisis. The Navy, too, played its part in this charade by opting for a design that specifically excludes Kaveri, even if it were to be qualified in the future! Yes, were can create Kaveri++ but that would take too long a time and that proposal would be dismissed for the same reason. (Navy also attempted to do the same with the NUH trying to specifically eliminate the ALH using innovative concepts such as AUW limit, but was then called out for this duplicity.)

While the GoI and the invisible 'bean counters' receive the bulk of the criticism, the real issues stem from the Services, which have failed (to put it mildly) to advocate and work towards the true independence in the aerospace industry. The GoI must proceed with caution because, if it forces the use of Kaveri in indigenous fighters, the 'experts' from the Services (and media too) will cry hoarse and raise alarms about compromising national security and the safety of servicemen by opting to develop subpar products in the name of patriotism. A leader like Indira Gandhi might have kept them in check, but such leadership is an exception, not the rule. As a result of these issues, having set Kaveri up for failure, funding has dried up and future looks bleak.

[fanne]

I agree Apna sikka hi Kyoto hai

[VinodTK]

Well stated Basant jee

[Kailash]

Basant ji, thought I see the logic in your argument.

But I feel research funding/timelines should not be held captive to requirements of services. In other words, engine research should be sustained with a vision for a family of useful engines ranging from turbo-shaft, -prop, -jet , -fan with as much commonality. Must drop this bean counter mentality wrto basic research. What we have we should produce in scores.

Secondly and more importantly, once a particular engine SKU reaches certain level of maturity and reliability, a platform should be quickly wrapped around that engine to make a useful product. IAF or IN have no use for a standalone engine. For them it will be the final product that matters. If you can't sell it to Indians, sell it to the world. Make for the world will never world if research institutes keep chasing perfection. Products lead to profits, royalty leads to sustainability.

And of course budgets need to become 6-10 folds, with built in autonomy to use those funds. More accountability should be on the platform makers, less on the engine makers.

I know this is a bit controversial if you limit the end user to be only your services. MIC won't be made in a day, and an efficient one needs large numbers. Quantity does have a quality of its own.

[maitya]

Kaveri engine approved for inflight testing: A breakthrough in Indian aerospace

Just one statement from us on IAH on youtube that gtre told us way back in 2017 that kaveri had passed safran's audit and was cleared for flight trials has resulted in god knows how many articles in the last one week

Prasadji, you are not helping here - there's so much confusion as it is:
1) The news report that I've linked above, is quoting some "GTRE official" or somebody, on a very recent date (23rd Dec 2024) . To quote:

India's Gas Turbine Research Establishment (GTRE), part of the Defence Research and Development Organisation (DRDO), announced the Kaveri engine's clearance for inflight testing on December 23, 2024.

So, pls clarify what this news item has got to do with Safran Audit etc of 2017-18 vintage (then reported by you/your-org, and actually by a few other news orgs as well)?

2) What has now become quite intriguing is, what does this "... cleared for flight trials ..." really means.
a) First fundamental question is: Which Kaveri version is this all about - old K9, dry-Kaveri variant or the new K9* (dry-Kaveri by Godrej plus brand-new AB from Brahmos Aerospace). Which one?

b) Second Fundamental question is: What kind of flight-tests?
In this context, on one hand, Alpha Defense is claiming/reporting another round of High-Alt inflight testing of the dry-Kaveri in Russia (onboard the IL-76 testbed), presumably to certify the recently-achieved 52KN dry thrust rating, via the new-Fan route.
This news about this new Fan came out about an year back, a few months after dry-Kaveri had gone for it's earlier round of in-flight High-Alt testing (and had achieved 48.5KN).

Other few news items are claiming about commencement of full flight-testing i.e. onboard a supersonic, presumably twin-engined, platform (like MiG-29).
So, which one ...
Pls clarify, if you are can/aware, what's going on.

As for CMCs, the nozzle flaps are the first place they'll be used. Next are C/SiC or SiC/SiC (forgot which but must be the latter) engine shrouds. It was a 2 yr program I think and must be ready by now. Same with the PMC bypass duct. Rotating parts will take time and we still don't have gamma Ti-Al either. We could get that from the frenchies (they use it on leap engines). So DS blades it is until either of them get to required maturity.

Well, PMC based bypass duct (which provided substantial weight savings - reportedly reduction of 6 Kgs (from 32kgs to 26Kgs), was reported about 2 years back - so should be in use now.
Similarly NAL mastering CMC (SiC/SiC) nozzle flaps (and V-Gutter, exhaust Cones as well) also just got reported - so yes, CMC shrouds, PMC casings etc are thus, extremely likely as well.
(Best of all, hidden in that news item is full ToT to an industry partner)

However, all of these are AB components (except of course the shrouds etc), so if any weight savings is to accrue, it'd be in the AB segment - i.e. not going to mean much for the Kaveri dry variant.

Wrt the Kaveri dry variant, the interesting aspect of this recent report is the mention of this generic term, "Hot end components" - which can mean anything, starting from AB, to the turbine (both HPT and LPT) blades, to the turbine vanes (so static), to the combustor (liners), to the compressor blades (especially the last stages) etc etc.
As of now, wrt usage of CMCs in rotating parts, the published cutting edge 5th Gen TF tech globally, are exclusively wrt LPT Blades and Vanes. CMC tech has not yet matured enough for their application in HPT Blades or Vanes, where the temp regimes (i.e. temp regimes >1350deg C) are way beyond the current SiC/SiC CMC materials.

But then again, SiC/SiC reported here is 2D - whilst LPT Blades (or Vanes) would need to be 3D.
So, this "SiC/SiC usage in Hot end Components" doesn't indicate anything wrt usage in the Hot Core section of the Kaveri (dry or K9*).

Wrt y-TiAl, no idea where are we currently wrt Intermetallic (read y-TiAl) usage for LPT blades (like in M88-2) either.
Betw, do note, Safran mastered 3D mfg wrt y-TiAl usage for LPT blades, of M88, in late-90s/early-2000s.
I doubt, they will part such a niche tech so easily/cheaply, if at all.

[Rakesh]

...

I am glad you said the above. Great post by the way.

So we are right back where we started. In the absence of the IAF not advocating for developing its own turbofan, then how can any of the proposals you stated in your earlier posts actually work out?

IAF will not advocate and Govt will thus not sanction funds. That leaves the private sector.

But who in the private sector will then do this? And the answer to that question is here ---> viewtopic.php?p=2636539#p2636539

Moral of the Story ---> Not possible to put Kaveri on Tejas or any other platform (TEDBF, ORCA, etc), until it is completely certified.

For a service that *D-E-M-A-N-D-S* perfection from local maal, good luck trying to convince Air HQ of accepting an unproven product on a frontline fighter aircraft. For phoren maal, certainly yes and there are numerous examples of this in the past. Welcome to the hypocrisy that are the services.

[Rakesh]

Even the Chinese (the enemy) are telling India not to abandon the Kaveri program.

Each and every word below is true. Now I have seen everything. I can die in peace.

https://x.com/livefist/status/1873013628133318754 ---> Someone from China couldn’t take the Indian self-flagellation on Reddit. Wise words, though.

[Kailash]

This is a question to all seniors, why can we not delink a mission mode engine dependent initiative, incubate and fund it irrespective of customer wants? Why not design something around what we do perfect??

Kaveri is anyways a delinked project as far as LCA or AMCA is concerned. Then why the compulsion to stick to a customer demand? Do DRDO labs not work on upgraded avionics, radar and LRUs, even before a upgrade program is sanctioned in full? How is the engine any different?

[vera_k]

IMO, this is what is happening. Although attempts were made to find alternative applications (like naval propulsion), the engine was not of sufficient maturity to be used. The news we get every now and then is of efforts geared towards fixing the shortfalls identified so far.

[drnayar]

Even the Chinese (the enemy) are telling India not to abandon the Kaveri program.

Each and every word below is true. Now I have seen everything. I can die in peace.

https://x.com/livefist/status/1873013628133318754 ---> Someone from China couldn’t take the Indian self-flagellation on Reddit. Wise words, though.

.. that seriously a Chinese handle ?!.. wonders will never cease

IAF now needs to be told by the Chinese

[chetak]

Even the Chinese (the enemy) are telling India not to abandon the Kaveri program.

Each and every word below is true. Now I have seen everything. I can die in peace.

https://x.com/livefist/status/1873013628133318754 ---> Someone from China couldn’t take the Indian self-flagellation on Reddit. Wise words, though.

.. that seriously a Chinese handle ?!.. wonders will never cease

IAF now needs to be told by the Chinese

or someone who is trolling us, drnayar ji. The cheen have no love lost for India


nothing much to be gained by trudging the same old beaten path, without pausing, looking back, reassessing the ground situation, lessons learned can help in rearming and exploring options. Use some retired, reliable consultant(s), if available, even if you have to pay through the nose to seek options that can be pursued

[chetak]

This is a question to all seniors, why can we not delink a mission mode engine dependent initiative, incubate and fund it irrespective of customer wants? Why not design something around what we do perfect??

Kaveri is anyways a delinked project as far as LCA or AMCA is concerned. Then why the compulsion to stick to a customer demand? Do DRDO labs not work on upgraded avionics, radar and LRUs, even before a upgrade program is sanctioned in full? How is the engine any different?

Kailash ji,

with their demonstrated track record, where will the funds come from, who will fund another open ended fighter engine project with confidence, without a securely set timeline and tightly targeted end game of an engine ready to be productionized. Every failure results in someone getting shunted out, degrading their career prospects and and leaving them staring at bleakish looking future.

High tech sarkari projects have seriously high attrition levels at the mid to junior levels and they seriously bleed good talent to industry in exchange for much higher paychecks and opportunities to advance and perhaps to emigrate

most upgrades done are incremental in nature, there is nothing that has revolutionized avionics or weapons that has come out of any govt project.

If tangible progress is shown stage wise, then the required funds will flow easily. If not, then project managers will start to eat more that 2-3 samosas at frequent tea breaks, while smoking heavily through the day

[williams]

Provide the funding and then the above will surely work. GOI has to provide the funding. The GOI is the one that needs convincing.

Please allow me to conclude my thoughts and this will be my last post on this topic. I do not wish to absolve the GoI for the insufficient funding of the Kaveri project. That said, in my opinion, the real issue lies neither with the GoI nor with the so-called bean counters (whoever they may be). The GoI, regardless of the party in power, has consistently invested heavily in R&D once convinced. These include: (a) ISRO’s communication and dual-use/spy satellites, the Moon orbiter, the Moon rover, the Mars orbiter, etc.; (b) the Arjun MBT, ALH (including the Shakti engine), ATAGS, various radars, rockets, etc., for the Army; (c) ATV (nuclear sub), shipbuilding, NUH, NLCA (including the SBTF), etc., for the Navy; and (d) countless missiles, helicopters, EW systems, AEW, AESA radars, LCA Mk1/2, trainers, etc., for the Air Force. In fact, some of the most innovative products were only revealed after testing (e.g., ASAT) and I have not included the nuclear programmes, BMD programme and strategic missiles!

If that is the case, why doesn’t Kaveri receive the attention it deserves? The answer is simple: the IAF and the IN. I am yet to find a single IAF chief who strongly advocated for an indigenous engine to make India really self-sufficient in aircraft propulsion. On the other hand, the IAF sought to exclude Russian aircraft to avoid "over-reliance on Russia", and to promote `diversity' in their fighter fleet. To that end, they initiated the MMRCA program while fully being aware that the budget would be inadequate, and failed to have a contingency plan despite a decade-long process! Around the same time, they sought to equip many squadrons with Indian fighters powered by an engine from a country that imposed sanctions on us on that very programme! Was that engine an inevitable choice? No, we could have used an alternative engine from France or even shifted to a Russian engine, as these two countries stood by us during our crisis. The Navy, too, played its part in this charade by opting for a design that specifically excludes Kaveri, even if it were to be qualified in the future! Yes, were can create Kaveri++ but that would take too long a time and that proposal would be dismissed for the same reason. (Navy also attempted to do the same with the NUH trying to specifically eliminate the ALH using innovative concepts such as AUW limit, but was then called out for this duplicity.)

While the GoI and the invisible 'bean counters' receive the bulk of the criticism, the real issues stem from the Services, which have failed (to put it mildly) to advocate and work towards the true independence in the aerospace industry. The GoI must proceed with caution because, if it forces the use of Kaveri in indigenous fighters, the 'experts' from the Services (and media too) will cry hoarse and raise alarms about compromising national security and the safety of servicemen by opting to develop subpar products in the name of patriotism. A leader like Indira Gandhi might have kept them in check, but such leadership is an exception, not the rule. As a result of these issues, having set Kaveri up for failure, funding has dried up and future looks bleak.

I am not sure it is IAF or INs responsibility to build indigenous capabilities. They are happy to use indigenous products where there is no alternative (example SSBN, missiles etc) imports for the money allocated to them or if a product can go through their rigorous testing standards. Their job seems to be to defend and fight current and future wars. And for some reason (not thinking about negative reasons) they like imported products until the local products are proven. This is probably what they are used to. Now some of the big ticket programs that you are talking about here may be got their push because they were under the PMO (correct me if I am wrong). it sounds to me, some sort of reorg needs to happen within defense ministry where the national priority of developing and handholding indigenous product development of national strategic importance. A fighter jet engine should come under that category. I wonder if the services have a forum to advocate indigenous products or even push DRDO for specific research. They seems to be quite busy finding reasons to reject the products or sneak in a import somehow. We cannot rely on political leadership to change this trend. We need to institutionalize and incentivize local product development and use.

[konaseema]

With 4 programs (Tejas Mk1/A, Mk2, TEDBF & AMCA Mk1) that need 2 different types, the best possible option is to fund initiatives that will result in 2 different engines with 5% - 10% more thrust over GE 404 & 414 engines when these aircrafts need replacement engines. This buys us around 10 years to develop, test and get these 2 engines certified. How the GTRE go about it is to be decided between enhancing the current Kaveri engine (weight reduction and a better AB) or a clean sheet design to build 2 new engines and leave Kaveri core to power Ghatak. Instead of setting the specs that will match or better every aspect of the engines that it will replace, the requirement should be set to what is acceptable as the MVP for both engines (Mk1) and preferred requirement (MK2), so that we get the engines delivered on time.

[maitya]

With 4 programs (Tejas Mk1/A, Mk2, TEDBF & AMCA Mk1) that need 2 different types, the best possible option is to fund initiatives that will result in 2 different engines with 5% - 10% more thrust over GE 404 & 414 engines when these aircrafts need replacement engines. This buys us around 10 years to develop, test and get these 2 engines certified. How the GTRE go about it is to be decided between enhancing the current Kaveri engine (weight reduction and a better AB) or a clean sheet design to build 2 new engines and leave Kaveri core to power Ghatak. Instead of setting the specs that will match or better every aspect of the engines that it will replace, the requirement should be set to what is acceptable as the MVP for both engines (Mk1) and preferred requirement (MK2), so that we get the engines delivered on time.

konaseema-ji, the MVP for both was/is K9 - and,
i) K9* (dry-Kaveri + brand new AB) is the F404 equiv devt of this MVP.
Actually it is the K10 (the productionised version) where the weight would have to go to <1T.

ii) Kaveri+ is the F414 equiv devt, again based on this very same MVP, but with further incremental tech-infusion (some maybe of the 5th Gen genre).

iii) Developing any 120KN thrust-class (say Kaveri++), will require a brand new MVP, but that will be coming out of the Kaveri+ program - with even more incremental 5th Gen genre tech infusion.

So all that is needed is to flight-test and certify the MVP(K9) ASAP - unfortunately something that should have happened from 2012, and completion by 2015 etc, but didn't. Now, if any of these news-items are even partially true, and if a K9* gets fully certified in next 3-4 years, we are well and truly on our way wrt achieving all three of the above ((i), (ii) and (iii)).

Do note any strategic program, like developing TF capability, will mandatorily involve keeping-up to futuristic TF technology dev as well - without these technology infusions the next step of incrementally-updated MVPs wouldn't come thru.
So, going back to 3rd Gen TF like Adour, won't help in coming up with a MVP for these three etc.

Also note, cutting-edge tech devt is always incremental and just-like Mk1 -> Mk2 -> AMCA is the tech devt route, so is for K9* -> Kaveri+ -> Kaveri++.
And just like the tech-dev-illiterate folks, who are recently advocating cancelling Mk2 and directly jumping to AMCA etc, so is the case with TF D&D roadmap - can't remove the intermediate steps (like Kaveri+) and straightway jump to 120-130KN class TF, from a 80-85KN TF dev program.
The inglish-rich verbiage of "tech leap-frogging" etc, that gets trotted around well too often by the import-pasand shills, is just that - somehow wean away the tech-illiterate decision-makers, and lead them to a dreamy garden-path of ToAsT deals of various hues, only to waste more years and maybe even permanently damage the tech capability-dev initiatives.
So that turd-world developing countries like ours, remains forever import-dependent, and thus, bereft of any strategic autonomy.

Anyway, coming back to the topic, do note however, that above doesn't mean we don't need a Adour-class (27-29KN) light-weight TF - we do, and for that kind of TF, the MVP is HTFE-40 (which, after a great start, unfortunately, has got no updates for last 2 years - may have been mothballed).

Betw STFE is the MVP for ultra-light (and small) TF class - and with Manik (the K10 equiv of STFE) is more or less on it's way.

There, you now have an indigenous TF D&D "vision" laid out ... however difficulty is always wrt implementation!!

[fanne]

For point 1 and 2 (k9) is the thought process is that it will give 50 kn of dry and 85 kn of afterburner. Increase the size of the fan (same as f 414), an increase in 22% area wise and increase afterburner thrust to 98 kn ( with equivalent gain in dry thrust say at 60 kn). Perhaps with the same core. Is that the thought process?

[Kailash]

Every failure results in someone getting shunted out, degrading their career prospects and and leaving them staring at bleakish looking future.

High tech sarkari projects have seriously high attrition levels at the mid to junior levels and they seriously bleed good talent to industry in exchange for much higher paychecks and opportunities to advance and perhaps to emigrate

Attrition is a known factor in any industry, you have plan around it, mitigate it with more hiring, better pay and opportunities. Looking at failures as a way of pinning blame needs a generational change - won't be easy.

Instead of meager budgets and one engine, what if there is substantial funding and a family of engines would there be more work to shuffle but retain talent ?

most upgrades done are incremental in nature, there is nothing that has revolutionized avionics or weapons that has come out of any govt project.

If tangible progress is shown stage wise, then the required funds will flow easily. If not, then project managers will start to eat more that 2-3 samosas at frequent tea breaks, while smoking heavily through the day

Project and program management are sorely lacking. Lack of project efficiency, technical accomplishments and budgets are independent problems. Our approach is a non starter in terms of solutions. Given more money, MoD must work on the efficiency and talent retention. With persistence, engine improvements will come last, after many failures. If we can't fund projects and take failures, Good luck!!

Sorry if I am unable to withhold the frustration. We seem to be tying ourselves in knots, so well.

[Rakesh]

...

I forgot to mention that Baba Kalyani also wants to develop a turbofan. Lets hope he is successful.

India May Take a Decade to Develop Its Own Fighter Jet Engine, Says Bharat Forge’s Baba Kalyani
https://raksha-anirveda.com/india-may-t ... a-kalyani/
06 Feb 2021

[sanjayc]

Just have a JV between ISRO, GTRE and Bharat Forge, and you will have a jet engine in less than a decade.

[Rakesh]

There are desh drohis (some influential stakeholders) within India who do not want her to have her own turbofan. Our greatest enemy lives within our own borders.

[ernest]

India May Take a Decade to Develop Its Own Fighter Jet Engine, Says Bharat Forge’s Baba Kalyani
https://raksha-anirveda.com/india-may-t ... a-kalyani/
06 Feb 2021

To add, Kalyani is also developing small jet engines for UAV/LM/Cruise missiles. The below article quotes him on one UAV jet engine. Don't know progress on this or the rest.

https://www.business-standard.com/artic ... 856_1.html

Good area to start as small jet engines will be required in bulk of varying specs.

[tandav]

Its important to have multiple competing manufacturers. India only have one HAL which has no competition therefore has very little accountability. Perhaps some advanced State governments should start Aerospace companies like China has done.

The Chinese have 3+ aerospace champions (AVIC, CAC) with an entire ecosystem of sub vendors. And a huge number of private players like DJI in drones.
CAC: Chengdu Aerospace Corporation
SAC: Shenyang Aerospace Corporation
XAC: Xian Aerospace Corporation : Transport Aircraft
COMAC: Commercial Aircraft

USA too has competing manufacturers
Boeing
McDouglas
Lockheed Martin
Northrup Grumman
General Dynamics

Russia
MIG
Sukhoi
Antonov
Kamov

[Kailash]

Idrw reports substantial progress in the 130KN twin engine test bed facility by GTRE

[Rakesh]

Idrw reports substantial progress in the 130KN twin engine test bed facility by GTRE

Please Sir, not IDRW of all sources.

[williams]

Idrw reports substantial progress in the 130KN twin engine test bed facility by GTRE

Please Sir, not IDRW of all sources.

Looks like the news is legit. Some of these facilities were planned in around 2016 according to this DM MoS answers to the parliament: https://eparlib.nic.in/bitstream/123456 ... /36494.pdf. Seems like they are progressing good in building large ground testing facilities in North Bengaluru. This twitter handle has reported a sat image of the facility in March. https://x.com/Archit_Ch/status/1773410415025779141. That means they are not completely sleeping . However things are not moving according to our Jingo timeline and the whole GE engine delays has caught us with further delay in Mk-1A timeline. That said, we need to get more private sector participation and at some point we need private sector efficiencies in HAL. The other day I was watching this video of HAL shop floor and a cat (at 27.56) was walking across the facility in the background. That too right behind the GE engine and when the CMD was explaining about privatization . I am not sure if this is a SDRE thing, or the cat is helping out in catching the rats , but no private enterprise will allow little pets in the shop floor.

[fanne]

Cat warrior plane first in animal form and then in plane form maybe?

[maitya]

For point 1 and 2 (k9) is the thought process is that it will give 50 kn of dry and 85 kn of afterburner. Increase the size of the fan (same as f 414), an increase in 22% area wise and increase afterburner thrust to 98 kn ( with equivalent gain in dry thrust say at 60 kn). Perhaps with the same core. Is that the thought process?

fanne-ji, first and foremost, wrt any such up-thrusting etc requirement, never-ever look at the wet thrust values as an goal to be achieved - it is always about, barring the aam junta/clueless reporters small-talk, dry thrust increment, as an primary goal.

Now, normally the convention is, upto 10-12% increment of the dry thrust are attempted by tinkering with the LPT/Fan combo - but for anything beyond that, the hot core will mandatory require changing.
However even here, there's a big catch - this is normally true for "decent" BPR values of a low-BPR TF (min 0.4/0.5 etc). And for Kaveri-like, ultra-low BPR TFs, such 10-12% will be a huge ask.

To go from 51KN to 60-62KN, is approximately 20% up-thrusting, so the entire core will require modifying/changing.
One of the good example of this is, ironically, the F404->F414 evolution - where-in not only the Fan, but the entire core had be modified (actually the entire core went almost 0.5 gen ahead, technologically).

And as I've said innumerable times now, the F404->F414 is a true-blue 4th Gen TF technological evolutionary path, of evolving a barely-4thGen -> 4.5Gen benchmark state.
There are multiple indicators of this, but the most striking are,
1) increasing in overall mass-flow (by ~16%, via an larger Fan), so that overall thrust can be increased

2) but reduction in BPR (from 0.4 to 0.25) - which would mean increasing the mass-flow thru core (contributed by both 1 and 2). This reduction also diminished the dry-thrust increment proportion via the LPT/Fan-LPC route.

3) but such an increase (in mass-flow) is matched with increase/higher TeT (from 1390-1400deg C to ~1520-30deg C) - which means more work extraction by the HPT stages, and thermal-efficiency is maintained.

4) and higher TeT in turn is matched with higher OPR (from 26:1 to 30:1), mostly contributed by the HPC stages.
As any unilateral increment of the TeT, without matching increment of the PRs, would have adversely impacted any work extraction (by the HPT stages) and thermal efficiency (impacting SFCs)

5) and this higher HPC PR is achieved by using "lighter" blisk-based HPC stages (thus increasing the HPC rpm)
etc etc.

What these essentially means, a quantum-jump in turbomachinery and material technology, in both the Hot sections (especially the turbines and vanes) and the cold sections (HPC), via:
1) an improved multi-pass turbine blade (and vanes) cooling architecture (with laser drilled Film cooling) and TBC
2) usage of atleast 4th Gen SC turbine blades - paired with PM discs. I think GE decided to use SC blades both for HPT and LPTs, whilst the LPT blades are solid thus obviating "wasting" cooling-air from compressor stages
3) blisk-based HPC stages
etc etc.
That's the reason F414 is often considered the pinnacle/benchmark of 4.5Gen TF tech.

Now coming back to understanding the K9->Kaveri+ possible evolution path, one needs to consider the F404-F414 evolution (as above) carefully.
But before that, for K9->Kaveri+ evolution, its's pertinent to point out the huge constraint that's already in place:
The mass-flow of K9 is already comparable to those of F414 (~78Kg/s). So the luxury of thrust-increment (even if partially) via standard practice of mass-flow increment (like in F404->F414 by ~16-17%) will not be there.

But the flip-side of this relatively higher mass-flow of K9 (paired with low BPR), is thru-and-thru to address the flat-rating (i.e. ISA SLS + 20deg C) requirement.
GE (just like most other TF OEMs globally) ofcourse, never had any compulsion to design TFs, keeping the ambient env of our country.
So F404/F414/M88/EJ200/RD-33 et all, are all benchmarked at ISA SLS - which means, any platform using these in our country will experience derated thrusts in various times of the year. Which ofcourse, being imported maal, is all kosher to our import-pasand user-community - but can't be made applicable for desi products, isn't it?

So net-net, K9->Kaveri+ would be more onerous/challenging than the vanilla F404->F414-402 evolution - and IMVHO, would require mastering substantial aspects of the 414-402 -> 414-EPE technological evolution, and some more.

Some of the technological leapfrogging required, that I can think of, are as follows:
1) A true-blue blisk Fan for the LPC complex (with ~4 PR - currently 3.4 in K9) - this will give us some amount of mass-flow-induced-dry-thrust increment, though not a whole lot - say around ~5-7%

2) 1550+ deg C TeT capable HPT complex (so ~100 addn deg compared to DS-blade based K9 turbines) via,
-- a) 1125-1150deg C capable 4th Gen SC turbine blades and vanes (currently 1050deg C via DS)
-- b) implementing minm 400deg C of "cooling advantage" via "better" multipath blade-cooling architecture (including film-cooling via laser-drilled holes) and 8-YSZ based EBPVD TBC

3) A much lighter LPT complex - either via intermetallic y-TiAl based 3D mfg blades (a la M88-2) or via SiC/SiC CMC blades (5th Gen tech)

4) Improved HPC PR to ~7 (current 6.4 in K9) levels, via,
-- a) improved efficiency of the HPC stages to 0.89-0.92 (current 0.85 in K9) levels via blade design improvements, reducing secondary losses, casing treatments etc
-- b) Lighter HPC stages via all-blisk design
-- c) Lighter last HPC stage(s) via CMC or y-TiAl
etc etc.
(Do note betw pt1 and pt3 above, will allow the BPR to go up to ~0.25 levels, without too much compromising on the mass-flow thru core aspects)

So, summary is, IMVHO, K9->Kaveri+ evolution will involve mastering (and productionising) quite a few of the, more-than-contemporary TF technologies - as without these futuristic technology infusions such an evolution won't be possible.
And IMVVHO, it seems, quite a few of these technology D&D have been in silent-R&D mode, for around decade now, despite zero budgetary and institutional support.
This is what still gives old-fools like moi, some hope after all!!

[SRajesh]

Maityaji
Correct me if I am wrong.
For a K9 to any other Avatar a la F404 to 414, there needs to be a commercial mass production base and usage to correct glitches. And then to build next gen!
And I mean engine on some thing that used on a regular basis and not in a experimental set up.
And for that to happen we need two hands to clap i.e., GTRE/HAL/Private to build these engines say two to three a month and IAF to have something to use it on
Now unless these two entities agree on production and using it in current state, why will the Bean-Counter dole out more cowries!!!
We are not going get uber 5th gen engine and no gora is ever going to hand hold and let us build one(regardless of what one is willing to pay)
We need to find a bird willing to accept K9 manned or unmanned
To use an analogy: Agni did not come out of someone's aboral end one fine morning.!!
A lot of sweat and tears and Army buying into Prithivi (given our precarious status then) got us there

[Cain Marko]

For point 1 and 2 (k9) is the thought process is that it will give 50 kn of dry and 85 kn of afterburner. Increase the size of the fan (same as f 414), an increase in 22% area wise and increase afterburner thrust to 98 kn ( with equivalent gain in dry thrust say at 60 kn). Perhaps with the same core. Is that the thought process?

fanne-ji, first and foremost, wrt any such up-thrusting etc requirement, never-ever look at the wet thrust values as an goal to be achieved - it is always about, barring the aam junta/clueless reporters small-talk, dry thrust increment, as an primary goal.

Now, normally the convention is, upto 10-12% increment of the dry thrust are attempted by tinkering with the LPT/Fan combo - but for anything beyond that, the hot core will mandatory require changing.
However even here, there's a big catch - this is normally true for "decent" BPR values of a low-BPR TF (min 0.4/0.5 etc). And for Kaveri-like, ultra-low BPR TFs, such 10-12% will be a huge ask.

To go from 51KN to 60-62KN, is approximately 20% up-thrusting, so the entire core will require modifying/changing.
One of the good example of this is, ironically, the F404->F414 evolution - where-in not only the Fan, but the entire core had be modified (actually the entire core went almost 0.5 gen ahead, technologically).

And as I've said innumerable times now, the F404->F414 is a true-blue 4th Gen TF technological evolutionary path, of evolving a barely-4thGen -> 4.5Gen benchmark state.
There are multiple indicators of this, but the most striking are,
1) increasing in overall mass-flow (by ~16%, via an larger Fan), so that overall thrust can be increased

2) but reduction in BPR (from 0.4 to 0.25) - which would mean increasing the mass-flow thru core (contributed by both 1 and 2). This reduction also diminished the dry-thrust increment proportion via the LPT/Fan-LPC route.

3) but such an increase (in mass-flow) is matched with increase/higher TeT (from 1390-1400deg C to ~1520-30deg C) - which means more work extraction by the HPT stages, and thermal-efficiency is maintained.

4) and higher TeT in turn is matched with higher OPR (from 26:1 to 30:1), mostly contributed by the HPC stages.
As any unilateral increment of the TeT, without matching increment of the PRs, would have adversely impacted any work extraction (by the HPT stages) and thermal efficiency (impacting SFCs)

5) and this higher HPC PR is achieved by using "lighter" blisk-based HPC stages (thus increasing the HPC rpm)
etc etc.

What these essentially means, a quantum-jump in turbomachinery and material technology, in both the Hot sections (especially the turbines and vanes) and the cold sections (HPC), via:
1) an improved multi-pass turbine blade (and vanes) cooling architecture (with laser drilled Film cooling) and TBC
2) usage of atleast 4th Gen SC turbine blades - paired with PM discs. I think GE decided to use SC blades both for HPT and LPTs, whilst the LPT blades are solid thus obviating "wasting" cooling-air from compressor stages
3) blisk-based HPC stages
etc etc.
That's the reason F414 is often considered the pinnacle/benchmark of 4.5Gen TF tech.

Now coming back to understanding the K9->Kaveri+ possible evolution path, one needs to consider the F404-F414 evolution (as above) carefully.
But before that, for K9->Kaveri+ evolution, its's pertinent to point out the huge constraint that's already in place:
The mass-flow of K9 is already comparable to those of F414 (~78Kg/s). So the luxury of thrust-increment (even if partially) via standard practice of mass-flow increment (like in F404->F414 by ~16-17%) will not be there.

But the flip-side of this relatively higher mass-flow of K9 (paired with low BPR), is thru-and-thru to address the flat-rating (i.e. ISA SLS + 20deg C) requirement.
GE (just like most other TF OEMs globally) ofcourse, never had any compulsion to design TFs, keeping the ambient env of our country.
So F404/F414/M88/EJ200/RD-33 et all, are all benchmarked at ISA SLS - which means, any platform using these in our country will experience derated thrusts in various times of the year. Which ofcourse, being imported maal, is all kosher to our import-pasand user-community - but can't be made applicable for desi products, isn't it?

So net-net, K9->Kaveri+ would be more onerous/challenging than the vanilla F404->F414-402 evolution - and IMVHO, would require mastering substantial aspects of the 414-402 -> 414-EPE technological evolution, and some more.

Some of the technological leapfrogging required, that I can think of, are as follows:
1) A true-blue blisk Fan for the LPC complex (with ~4 PR - currently 3.4 in K9) - this will give us some amount of mass-flow-induced-dry-thrust increment, though not a whole lot - say around ~5-7%

2) 1550+ deg C TeT capable HPT complex (so ~100 addn deg compared to DS-blade based K9 turbines) via,
-- a) 1125-1150deg C capable 4th Gen SC turbine blades and vanes (currently 1050deg C via DS)
-- b) implementing minm 400deg C of "cooling advantage" via "better" multipath blade-cooling architecture (including film-cooling via laser-drilled holes) and 8-YSZ based EBPVD TBC

3) A much lighter LPT complex - either via intermetallic y-TiAl based 3D mfg blades (a la M88-2) or via SiC/SiC CMC blades (5th Gen tech)

4) Improved HPC PR to ~7 (current 6.4 in K9) levels, via,
-- a) improved efficiency of the HPC stages to 0.89-0.92 (current 0.85 in K9) levels via blade design improvements, reducing secondary losses, casing treatments etc
-- b) Lighter HPC stages via all-blisk design
-- c) Lighter last HPC stage(s) via CMC or y-TiAl
etc etc.
(Do note betw pt1 and pt3 above, will allow the BPR to go up to ~0.25 levels, without too much compromising on the mass-flow thru core aspects)

So, summary is, IMVHO, K9->Kaveri+ evolution will involve mastering (and productionising) quite a few of the, more-than-contemporary TF technologies - as without these futuristic technology infusions such an evolution won't be possible.
And IMVVHO, it seems, quite a few of these technology D&D have been in silent-R&D mode, for around decade now, despite zero budgetary and institutional support.
This is what still gives old-fools like moi, some hope after all!!

Maityaji, what would be the fastest route for a baseline kaveri (404 in56 level) to get to production and how long might this take?

Doesn't matter how much imported components there are in it. Maybe use an m88 eco core? ToT notwithstanding. Iows, just get the engine to production using whatever input from a reliable supplier.

[williams]

On the manufacturing front I think we are very close to seeing a UCAV with dry Kaveri. Godrej Aerospace is tasked to manufacture 48 kN dry Kaveri and seems like it is going very well. It is still a shame that we have not acquired a flying test bed. I think these engines will have to go through another round of testing in Russia before they start integrating with the Ghatak PVs. I guess that will provide some real world experience. Right now we need to focus on mastering 4.x tech. As Maitya ji pointed out, leap frogging into 5.x tech will not be possible without mastering 4.x.

[vera_k]

GE (just like most other TF OEMs globally) ofcourse, never had any compulsion to design TFs, keeping the ambient env of our country.
So F404/F414/M88/EJ200/RD-33 et all, are all benchmarked at ISA SLS - which means, any platform using these in our country will experience derated thrusts in various times of the year.

Some of the earlier news reports claiming better performance achieved in flight testing makes me wonder.
Would the Kaveri engine show better numbers if it was benchmarked at ISA SLS? If yes, then publishing both flat rating and ISA SLS numbers would allow for an apples to apples comparison.

[Kailash]

https://youtu.be/gwH7R4fvpQs

S Jha is one of the sane voices i respect. He does acknowledge we need an omnibus program with large budget for engine development. Lot of information there about mk2, our fighter production/testing and aero engines. Engine related content from around 50 minutes

[ashishvikas]

HAL forms panel to negotiate GE-F414 deal with US, aims to ink it by March 2025

https://www.aninews.in/news/national/ge ... 231215329/

[fanne]

Thanks Maitya ji, it looks like this base design with material improvements will cater to f404, f414 and perhaps 110kn to 120kn level of thrust. So this can take care of tejaskmk1, mk2, tedbf and AMCA (like even if we does not have adaptive thrusting capability built in design). The basic design philosophy looks like solid and well thought out from future requirement perspective. We just need to diligently keep following this path.

[konaseema]

Please Sir, not IDRW of all sources.

Looks like the news is legit. Some of these facilities were planned in around 2016 according to this DM MoS answers to the parliament: https://eparlib.nic.in/bitstream/123456 ... /36494.pdf. Seems like they are progressing good in building large ground testing facilities in North Bengaluru. This twitter handle has reported a sat image of the facility in March. https://x.com/Archit_Ch/status/1773410415025779141. That means they are not completely sleeping . However things are not moving according to our Jingo timeline and the whole GE engine delays has caught us with further delay in Mk-1A timeline. That said, we need to get more private sector participation and at some point we need private sector efficiencies in HAL. The other day I was watching this video of HAL shop floor and a cat (at 27.56) was walking across the facility in the background. That too right behind the GE engine and when the CMD was explaining about privatization . I am not sure if this is a SDRE thing, or the cat is helping out in catching the rats , but no private enterprise will allow little pets in the shop floor.

As per the MD, HAL is ploughing back 15% of its profits into R&D, which is impressive.

[ritesh]

Shiv on Jet engines...
https://x.com/shiv_cybersurg/status/1874677854157574156