Kaveri & Aero-Engine: News & Discussion

[drnayar]

Source : https://x.com/amitmalviya/status/190728 ... XrvXw&s=19

Not sure of authenticity..

[bala]

Again not sure about this but L&T is being roped in for Version 2.0 of Kaveri for Tejas MK1A, AMCA crafts.

Pathikrit Payne with Aadi Achint discuss the above topic:

youtube.com/watch?v=xa3I5F1Fg4E

[Rakesh]

Source : https://x.com/amitmalviya/status/190728 ... XrvXw&s=19

Not sure of authenticity..

This is the last reported news on Kaveri...

Kaveri engine approved for inflight testing: A breakthrough in Indian aerospace
https://manufacturing.economictimes.ind ... /116615602
24 Dec 2024

[maitya]

From X - @shreedharsingh9:
HTSE - 1200 engine


Key tech points to note:
1) Effusion cooling architecture (but for Combustor) - since HAL engine div is mentioned, it must be the 3D-printed TF component capability from the HTFE program. This is a fantastic capability demonstration.
2) SX based Gas Generator (read Turbine Blades/Vanes) - must be hollow blades (with TBC) of AL-31F genre (1493deg K capability)
3) Imported Laser Shock Peening (of the compressor blades) - will reduce secondary losses in the compressor stages, resulting higher stage PR of the HPC stages. Refer to my earlier posts, how surface improvements like this, impacts the Compressor efficiencies!!
4) 13.25PR via only 2 compressor stages - Centrifugal Compressor, so a rotating impeller (Fan) and a diffuser pair. Very good perf!!
5) SFD tech to manage vibrations in the GG rotors

[Prasad]

maitya,
the sx blades are from dmrl.

[maitya]

maitya,
the sx blades are from dmrl.

Must be - though I think they are CMSX4 (2nd Gen SX) based, which in turn would mean ~1075-90 deg C raw-metal-temp capability.

But do note 1493deg K (1220deg C) TeT, is way too low for a SX-based blades that employs both, film-cooling* (~250deg C adv) and also with TBC (~150deg C adv) - ofcourse, that also doesn't mean absence of internal blade-cooling architecture etc.
Contrast it with HAL developed In718 (so poly-crystalline) based 3D printed cooled blades (and NGVs), for HTFE, that supports 1455deg K.
Similarly the SX blades (equiv to 2nd Gen, roughly) of AL-31F, support TeT 1390deg C TeT ... so must be of same genre.

[Kailash]

https://manufacturing.economictimes.ind ... /119742196

[AdityaM]

Source : https://x.com/amitmalviya/status/190728 ... XrvXw&s=19

Not sure of authenticity..

April Fools

[VishnuS]

maitya,
the sx blades are from dmrl.

Must be - though I think they are CMSX4 (2nd Gen SX) based, which in turn would mean ~1075-90 deg C raw-metal-temp capability.

But do note 1493deg K (1220deg C) TeT, is way too low for a SX-based blades that employs both, film-cooling* (~250deg C adv) and also with TBC (~150deg C adv) - ofcourse, that also doesn't mean absence of internal blade-cooling architecture etc.
Contrast it with HAL developed In718 (so poly-crystalline) based 3D printed cooled blades (and NGVs), for HTFE, that supports 1455deg K.
Similarly the SX blades (equiv to 2nd Gen, roughly) of AL-31F, support TeT 1390deg C TeT ... so must be of same genre.

Bhai, I met one of the directors of HTFE during 2020 DefExpo.

He had a long conversation, I couldn't find the audio clip of that conversation. But one thing I clearly remember was that Hot section of HTFE doesn't have any Rehenium. He said it is not possible to add Re as the 3D printing doesn't allow this. The plan was to maintain temp by using cooling channels and that was the primary reason for choosing 3D printing.

Our conversation revolved mostly around 3D printing.

You probably knew this and maybe more about the alloy too. Just thought of sharing with you here.

[maitya]

Must be - though I think they are CMSX4 (2nd Gen SX) based, which in turn would mean ~1075-90 deg C raw-metal-temp capability.

But do note 1493deg K (1220deg C) TeT, is way too low for a SX-based blades that employs both, film-cooling* (~250deg C adv) and also with TBC (~150deg C adv) - ofcourse, that also doesn't mean absence of internal blade-cooling architecture etc.
Contrast it with HAL developed In718 (so poly-crystalline) based 3D printed cooled blades (and NGVs), for HTFE, that supports 1455deg K.
Similarly the SX blades (equiv to 2nd Gen, roughly) of AL-31F, support TeT 1390deg C TeT ... so must be of same genre.

Bhai, I met one of the directors of HTFE during 2020 DefExpo.

He had a long conversation, I couldn't find the audio clip of that conversation. But one thing I clearly remember was that Hot section of HTFE doesn't have any Rehenium. He said it is not possible to add Re as the 3D printing doesn't allow this. The plan was to maintain temp by using cooling channels and that was the primary reason for choosing 3D printing.

Our conversation revolved mostly around 3D printing.

You probably knew this and maybe more about the alloy too. Just thought of sharing with you here.

Rhenium is normally added to Single-Crystal Ni-Superalloys (2nd gen onwards) to enhance its creep resistance.
(Geek Note: Re significantly reduce the diffusion rate of two-phase interface γ'/γ - which effectively hinders the dislocation movement and enhance the high-temperature stability of the superalloy)

However for 3D-printing of SX based HPT/LPT blades, the powder processing technology of the SX-Superalloy needs to be developed first - followed by coming-up of the actual 3D printing parameters, those that needs to be arrived empirically (sometimes called DoE in technical parlance).

Currently there are no SX Ni-Superalloy for which this technology exists in India, so no SX based Superalloys are used in HTFE.
Instead HTFE uses IN718 Poly-crystalline Ni-Superalloy for which both the powder processing tech and the 3D-printing parameters, already exists - but obviously, being polycrystalline, IN718 doesn't use/have Re.

Added Later:
The primary reason why 3D-printing tech is used for HTFE turbines, is due to smaller size of the blades - the casting-difficulty level goes up exponentially with smaller blades (which also needs to accommodate intricate internal-cooling channel architecture), but with 3D printing tech, size etc is not an issue.

PS: My thought/wet-dream: If HAL (Engine Div) is taking so long to realise HTFE, they should have also developed Effusion-cooling tech for blades/vanes by now ( Effusion cooling is more or less intrinsic to 3D-printed blades/vanes mfg tech) - that would have easily bumped-up the TeT by atleast 150-200deg C more.
For reference, Effusion cooling tech is already used in HTSE combustor liner, and the tech itslef is considered 5+ Gen (wrt TF tech).

[Cybaru]

Must be - though I think they are CMSX4 (2nd Gen SX) based, which in turn would mean ~1075-90 deg C raw-metal-temp capability.

But do note 1493deg K (1220deg C) TeT, is way too low for a SX-based blades that employs both, film-cooling* (~250deg C adv) and also with TBC (~150deg C adv) - ofcourse, that also doesn't mean absence of internal blade-cooling architecture etc.
Contrast it with HAL developed In718 (so poly-crystalline) based 3D printed cooled blades (and NGVs), for HTFE, that supports 1455deg K.
Similarly the SX blades (equiv to 2nd Gen, roughly) of AL-31F, support TeT 1390deg C TeT ... so must be of same genre.

Bhai, I met one of the directors of HTFE during 2020 DefExpo.

He had a long conversation, I couldn't find the audio clip of that conversation. But one thing I clearly remember was that Hot section of HTFE doesn't have any Rehenium. He said it is not possible to add Re as the 3D printing doesn't allow this. The plan was to maintain temp by using cooling channels and that was the primary reason for choosing 3D printing.

Our conversation revolved mostly around 3D printing.

You probably knew this and maybe more about the alloy too. Just thought of sharing with you here.

Any timelines of when the first ground test begins for this engine? Also didnt they have a HTFE 2000 in works?

[fanne]

A Tejas mk3 is being advocated with 2 engine Kaveri. It is different than tedbf, it will be twin engine mk2, same wings etc etc. same as what mirage 4000 was to mirage 2000. If Kaveri indeed can do 50kn dry and 75kn wet, tejas Mk 3 will be then very similar to rafale.

[fanne]

Just a thought since in or oaf will not give any mig29 to test Kaveri, how hard is to make a dual engine lcamk1 or mk2. One engine can be f404 (or even 2 Kaveri). How hard it is to make dual engine lcamk1, keeping everything same , like wings etc but have two engine plane and use that for testing? The mk1a is proven aircraft from our side.

[pravula]

It’s easier and cheaper to add a pod on an old 747 and fill its belly with instrumentation.

[vera_k]

HAL had proposed a 2 engine LCA-N, but that idea lost out to ADA's TEDBF idea. Perhaps a 2 engine LCA-N now looks promising with the passage of time.

[fanne]

Particularly if it can fly with Indian engine -Kaveri

[bala]

Delivery of First Kaveri Engine

In a significant milestone for India's aerospace and defense sector, Godrej Aerospace has confirmed the delivery of the first two modules of the Kaveri derivative engine to the Gas Turbine Research Establishment (GTRE). The company, a key player in precision manufacturing, also announced that six additional modules are slated for delivery later this year, fulfilling a critical order placed by the Defence Research and Development Organisation (DRDO).

The order, secured by Godrej Aerospace in September 2022, involves the production of eight modules for a specialized Kaveri derivative engine. Unlike the original Kaveri engine, which was developed for fighter aircraft, this variant is a 48 kN dry engine without an afterburner. Sources indicate that this engine is intended for use in autonomous air vehicles, marking a step forward in India's indigenous unmanned aerial technology.

Indian News Analysis Apr 4, 2025
youtube.com/watch?v=IINU3huxMP8

[fanne]

Learned people can fill in but I believe 1 full engine is made of 6 or 8 modules.

[habal]

apparently latest batch of 16 kaveri engines (not derivative) has generated 102 kn thrust in high altitude tests in Russia. No news on printed media confirms this but flurry of youtube vids like this.

the 16 kaveri engines sent to russia included the kaveri 2.0 as well, and this was a highly guarded detail not unveiled until tests were completed and engines recd back in India.

?

[uddu]

The above news could be from future.

[VishnuS]

apparently latest batch of 16 kaveri engines (not derivative) has generated 102 kn thrust in high altitude tests in Russia. No news on printed media confirms this but flurry of youtube vids like this.

the 16 kaveri engines sent to russia included the kaveri 2.0 as well, and this was a highly guarded detail not unveiled until tests were completed and engines recd back in India.

I heard this news as 82 kN.

[VishnuS]

Bhai, I met one of the directors of HTFE during 2020 DefExpo.

He had a long conversation, I couldn't find the audio clip of that conversation. But one thing I clearly remember was that Hot section of HTFE doesn't have any Rehenium. He said it is not possible to add Re as the 3D printing doesn't allow this. The plan was to maintain temp by using cooling channels and that was the primary reason for choosing 3D printing.

Our conversation revolved mostly around 3D printing.

You probably knew this and maybe more about the alloy too. Just thought of sharing with you here.

Any timelines of when the first ground test begins for this engine? Also didnt they have a HTFE 2000 in works?

Bhai, I haven't been to AI or DefExpo since 2021.

So I don't know the story

[habal]

apparently latest batch of 16 kaveri engines (not derivative) has generated 102 kn thrust in high altitude tests in Russia. No news on printed media confirms this but flurry of youtube vids like this.

the 16 kaveri engines sent to russia included the kaveri 2.0 as well, and this was a highly guarded detail not unveiled until tests were completed and engines recd back in India.

I heard this news as 82 kN.

this is a different engine, 140 kN max thrust is targeted and whether it achieved that or not is not clear but 102 kN dry thrust was achieved in Russia high altitude tests while engine dry thrust target was previously at 90 kN. From my open source reading this engine is not Kaveri without afterburner called KDE but another variant rated for 90 kN which exceeded expectations during Russian high altitude tests. Some sources have given this name as ganga which is an engine developed for AMCA.

This also clarifies a flurry of Kaveri 2.0 news recently while everyone was left wondering why Kaveri 2.0 was being discussed while KDE without afterburner was still work in progress with two samples delivered by Godrej

[basant]

The deadline for publishing this news was April 1. Probably was delayed due to CCS clearance.

[konaseema]

Whether this is a rumor or a prank for April 1st, the question we need to ask is "How close are we to achieving both the Dry and Wet thrust of a GE-404-IN20 caliber engine???" Given the time lapse since the funding was cut for the Kaveri engine program, how much would have GTRE achieved? Is it far from the realm of possibilities that GTRE would have achieved the Thrusts and Weight reduction needed to power the Tejas Mk1A fighter?

[maitya]

From X - @vatsalyamaurya: Russia has developed turbine blade and cooling architecture which allows tet upto 2000-2200 k


From X - @vatsalyamaurya: Materials in various Russian Engines


Very good data points.
Anyway, as I've said before, for >1600deg C TeT levels, that is now increasingly becoming standard for the 5th Gen TF Turbines, Effusion Cooling Tech is fast becoming mandatory - but for that HPT blade/vane 3D mfg capability is a must, and HTFE program has demonstrated it (albeit wrt 1st Gen polycrystalline IN718 Superalloy) approx 4-5years back.
So there's a pressing need for developing 3rd or 4th Gen SC (and also DS) Superalloy variants, which would support powder processing and 3D additive manufacturing capability!!

[maitya]

From X - @shreedharsingh9:

Jet Engine parts made from CMC materials

In this context, further details from@shreedharsingh9 in X: Russia's advancements wrt CMC Turbine Blades



Do note, CMC usage on rotor parts (of a TF) is currently limited to LPT blades (where ambient temp levels are of 900-1000deg C etc) - and they are all uncooled blades. Ofcourse they do sport a EB coating wrt oxidation resistance etc, but that's about it.
Anyway further note that Note CMC usage in TF predates this (e.g.Ge9X, LEAP etc), but they were all on static parts (HPT Shrouds, NGV etc) - GE has already implemented CMC on Turbine rotor applications in F414-EPE, ADVENT (future) etc, but 1350deg C, mentioned here, is absolute cutting edge.

Some more details in my old post here, wrt this.

Betw, this must be wrt Izdeliya-30 - and until now, some vague commentary like "ceramic usage in turbine" etc were getting published.
No wonder, with such cutting edge 5+ Gen Tech involved, Russians didn't/don't want us anywhere near it, despite us insisting from the FGFA days - so all kite-flying alternatives like 117/117S etc being offered, is going on.

[Prasad]

Them having cutting edge SiCf based CMCs and EBCs is sorta hard to believe. But if they have, that would be a massive achievement. Or are these roadmaps rather than anything at even TRL 2-3 levels?

[NRao]

Mod Note: Post videos with video title + description/summary of the video and not just the video. This is helpful for other readers who are following the thread. See the post as an example below...

[Rakesh]

Building jet engines in India: Experts chart post-Kaveri roadmap

At a panel discussion on 'The challenges of the fighter engine. Where do we go after Kaveri?' At THE WEEK Defence Conclave at Manekshaw Centre in New Delhi on Thursday, the panel, moderated by Air Marshal Ajay Kumar Arora (Retd), former Air OIC Maintenance, dissected the factors that hindered the progress of the jet engine and charted the way ahead. Dr S.V. Ramanamurthy, Director, Gas Turbine Research Estb (GTRE), Anshuman Tripathi, ex-adviser, National Security Advisory Board (NSAB), V. Venkat Raju, MD, VEM Technologies, Hyderabad and Air Vice Marshal Suresh Singh (retd) were partb of the esteemed panel.

[Kailash]

was this posted earlier - https://alphadefense.in/index.php/2025/04/13/key-improvements-in-the-kaveri-engine-by-gtre/

Talks a lot about weight reduction. Blisks for LPC/HPC stages, PMC ducts. Also talks of CMSX-4/TBC usage contributing to slight increases in TeT

[maitya]

was this posted earlier - https://alphadefense.in/index.php/2025/04/13/key-improvements-in-the-kaveri-engine-by-gtre/

Talks a lot about weight reduction. Blisks for LPC/HPC stages, PMC ducts. Also talks of CMSX-4/TBC usage contributing to slight increases in TeT

Nothing in this article that we haven't discussed, in great details, before ...
However disappointing is,
1) no news on LPT improvements. Gamma-TiAl route for LPT blades is more or less inevitable, if we are serious about even moderate increase to dry-thrust levels - since, I don't think, we haven reached that level of maturity wrt SiS-SiC CMC usage for rotary parts.

2) the distortion-tolerant Fan is bit of an overkill for std Kaveri (though must for KDE) - so was hoping new Fan design capable of some addn SPR (say 4.1:1), which in turn would have marginally (say 7-8% or thereabouts) improved the dry-thrust levels - especially when paired with a lighter LPT stage (i.e. Gamma TiAl based 3D manufactured LPT blades).

3) Complete silence on C-SiC based CMC static parts (e.g. Shrouds, Casings etc).

[Rakesh]

The ToAsT is not ready yet?

India hopes to launch F414 jet engine manufacturing line this year: Defence Secretary Rajesh Singh
https://www.cnbctv18.com/india/india-ho ... 88.htm/amp
29 April 2025

In a CNBC-TV18 exclusive, Defence Secretary Rajesh Kumar Singh said India hopes to operationalise a manufacturing line for GE’s F414 jet engines by the end of this year. The move is crucial to keep the Tejas Mark 2 timeline on track and marks a step forward in India’s defence self-reliance.

India hopes to launch the domestic manufacturing line for General Electric’s F414 jet engines by the end of this year, Defence Secretary Rajesh Kumar Singh said in an exclusive interview with CNBC-TV18. The development is critical for the timely production of the indigenous Tejas Mark 2 fighter aircraft. When asked about the status of negotiations between Hindustan Aeronautics Limited (HAL) and General Electric (GE), Singh said, "This year? I hope so. This is being led by HAL. We don't get into the nitty gritty of that negotiation, but on our part, we've been asking both players, as well as HAL, to try and expedite this so that our production schedule for the future Tejas—I think it's Mark 2—doesn't get affected. So yes, that is something that we are nudging from our side, but the nitty gritty of the negotiations we are leaving to these two agencies,” he added.

The government is closely tracking the price negotiations between HAL and GE and encouraging both parties to speed up the process, given the strategic importance of the Tejas programme and the wider goal of strengthening domestic defence manufacturing. The F414 engine is a key component for the Tejas Mark 2, an upgraded version of India's indigenous fighter jet. The ongoing deal with GE is expected to involve technology transfer and pave the way for local production, furthering India's long-term goal of strategic autonomy in aerospace. While the F414 engine will address near-term requirements through technology transfer and local assembly, Singh also reiterated that India’s long-term focus remains clear: the country wants full indigenous intellectual property rights (IPR) in aero engine manufacturing.

While Singh did not provide a specific timeline, the Defence Ministry’s push to expedite the process underscores the urgency of maintaining momentum in critical defence programmes and the broader push toward an Atmanirbhar Bharat.

[Rakesh]

https://x.com/ShiroBarks/status/1917809748549984406 ---> “Our skies must be powered by engines built in India, for India.”

• Fast-tracking the Kaveri
• Boosting public-private R&D partnerships
• Attracting foreign OEMs with co-dev & tech transfer
• Developing materials & testing for high-thrust propulsion

India prioritises homegrown aero-engine development after Pahalgam attack
https://english.mathrubhumi.com/news/in ... e-193bdc6d
24 April 2025

[Roop]

A Tejas mk3 is being advocated with 2 engine Kaveri.. ... same as what mirage 4000 was to mirage 2000. If Kaveri indeed can do 50kn dry and 75kn wet, tejas Mk 3 will be then very similar to rafale.

Roughly the same concept as ORCA.

[SRajesh]

Rakesh
I feel that Kaveri should have had test beds in India for validation
And Tejas should have been on whatever strength Kaveri had : Two Legged or Three legged.
At least to flood the skies in times of need.
And subsequent iterations would have delivered the 'Unobtanium'!!
But we need only 5.5 Gen capabilities in the light combat aircraft able to withstand Iron Mike' s best Right Hook onlee!!

[Cybaru]

I don't understand why we need LCA Mk3 and a new design. ORCA is already Mk3.

Rafale Dry and wet thrust with 50/75KN engine at MTOW 24.5K is 0.39/0.60 T/W ratio
ORCA + GE F414 Dry and Wet thrust ratio at MTOW of 23K is 0.50/0.84 T/W ratio
ORCA + Kaveri 1.0 dry and wet thrust ratio at MTOW of 23K is 0.41/0.60 T/W ratio
ORCA + Kaveri 2.0 dry and wet thrust ratio at MTOW of 23K is 0.51/0.77 T/W ratio

Plus Kaveri is flat rated! So better power in all regimes.
Get Kaveri version 1.0 to fly!

[maitya]

https://x.com/ShiroBarks/status/1917809748549984406 ---> “Our skies must be powered by engines built in India, for India.”

• Fast-tracking the Kaveri
• Boosting public-private R&D partnerships
• Attracting foreign OEMs with co-dev & tech transfer
• Developing materials & testing for high-thrust propulsion

India prioritises homegrown aero-engine development after Pahalgam attack
https://english.mathrubhumi.com/news/in ... e-193bdc6d
24 April 2025

The third bullet viz. "Attracting foreign OEMs with co-dev & tech transfer", is completely oxymoronic - other 3 ofcourse are fine.

Foreign OEMs, will only develop their own missing technologies (in TF domain) with our funding, and then simply hand-us-down a ToAsT kind of deal in return (of our investment) - some mfg, mostly CKD/SKD Assembly level Tech Transfer, that's all will be on the table.
Without a direct threat of an indigenous D&D based tech dev, which brings-in 5th Gen TF techs in parallel and independent of them, nothing much will ever get transferred, if at all.

Their mandatorily needs to be a permanent Damocles sword of funding tap-switch-off, anytime any hesitancy wrt sharing of their-developed TF tech is detected - which anyway will never happen, if the OEMs are aware that we are solely dependent (wrt our strategic programs, like AMCA) on them developing and transferring these TF technologies.
Always remember they are desperate of our funds, as their own governments had/have refused to fund them for these D&D programs - and this desperation needs to be leveraged to the hilt.

We never learn.

[Kailash]

Not sure what or how much technology infusion this means - co-production of jet engines with Japan
https://www.tribuneindia.com/news/india ... k-engines/

[Kailash]

Maitya ji, if these companies are so cash strapped, would it not make sense to buy them outright or at least take some strategic stake in in these companies?

Another noob question I have is don't we have a combined requirement for over 2000-3000 engines in the next twenty years? Will we not extract a better bargain and ToT if we have a much larger order book? Why only 99 engines?

I'm sure GE,RR or Safran understand/believe the 3000 number much more strongly than we ourselves do. Disclaimer - for the moment completely ignoring their unreliable nature and geopolitical vagaries that might result in them pulling the plug. Even if kaveri make up 15% that's 450 nos, and that's more than sufficient to establish a proper supply chain and establish quality and testing facilities