India Jet Engines and Gas Turbines

[Nilgiri]

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

The Kaveri engine developed by the Gas Turbine Research Establishment under the Defence Research and Development Organisation has been cleared for inflight testing. This marks a significant milestone in India's aerospace sector with the engine now ready for integration with unmanned aerial...

manufacturing.economictimes.indiatimes.com

 

[hugh]

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

The Kaveri engine developed by the Gas Turbine Research Establishment under the Defence Research and Development Organisation has been cleared for inflight testing. This marks a significant milestone in India's aerospace sector with the engine now ready for integration with unmanned aerial...

manufacturing.economictimes.indiatimes.com

Is it reasonable to expect the engines first flight(other than the Russian testbed) within a year?

 

[Nilgiri]

Is it reasonable to expect the engines first flight(other than the Russian testbed) within a year?

Doubtful, this program has been given very low priority for so many years now and its suffered....as seen by this long space of time between the first flying test bed tests with Russians earlier being ~ 10 years etc.

With catch up need (of larger jet engine propulsion ecosystem) and also trying to deploy it (dry version) on the Stealth UAV platform (which will also take some years to complete), it will probably proceed at its leisurely place, dependent on where things stand now with the FTB results whatever those are and the later feedback loop created from afterburner version.

India is unfortunately very red-tape bureaucrat heavy on a number of things and it costs India a lot. There was simply lot more intra-service consensus and impetus w.r.t: space, missiles, radars etc (where production was actually done to learn, iterate and take forward with concrete design freezes where needed) compared to jet propulsion and it shows.

 

[hugh]

India is unfortunately very red-tape bureaucrat heavy on a number of things and it costs India a lot. There was simply lot more intra-service consensus and impetus w.r.t: space, missiles, radars etc (where production was actually done to learn, iterate and take forward with concrete design freezes where needed) compared to jet propulsion and it shows.

I remember, reading online, Indians boasting Modi for his approach towards the country's "neglected" defence industry. I thought he brought some urgency to the indigenous defence programs?

I'm not a fan of Erdogan but he takes this business very seriously. It's either you deliver(and deliver on time) or get sacked. I wouldn't want to venture out of my depth regarding Indian politics or bureaucracy but political will and good execution are vital for any major defence projects, imho.

 

[Nilgiri]

I remember, reading online, Indians boasting Modi for his approach towards the country's "neglected" defence industry. I thought he brought some urgency to the indigenous defence programs?

I'm not a fan of Erdogan but he takes this business very seriously. It's either you deliver(and deliver on time) or get sacked. I wouldn't want to venture out of my depth regarding Indian politics or bureaucracy but political will and good execution are vital for any major defence projects, imho.

Well Kaveri was already separated from its major end-use (Tejas) in 2008 or so as it missed some crucial parameters. This preceded Modi coming to power, there was some impetus from one defence minister he had (w.r.t Tejas, but again Kaveri was already disjointed from it)....but the larger issue is Indian govt fiscal resource strain and way it handles this with bureaucrats it has (who is delegated with prioritisation where).

Once you unlock deterrence levels with nukes + missiles and have the 80s-90s situation where India was facing massive fiscal pressure at low GDP per capita along with internal, regional and international security pressure that needed opex (further constraining what you have for capex especially from statist tax+ public debt+spend which has its own pressure from rest of larger govt)....this just baked in lot of things to begin with at to decision tree forks in the road. Things like jet engines need large amounts of commited capex in the end.

It affects means to an end (objectives wise) approach in various branches of govt and especially defence bureaucracy....when you can do means for sake of means somewhat inductively....the GDP per capita is still very low so there is large fiscal pressure overhang always if you look at Indian govt budget and reluctance for deep reform there (that needs to really come first for that attitude to expand to where statism is much more entrenched w.r.t defence autarky) etc.

 

[dronie]

I remember, reading online, Indians boasting Modi for his approach towards the country's "neglected" defence industry. I thought he brought some urgency to the indigenous defence programs?

I'm not a fan of Erdogan but he takes this business very seriously. It's either you deliver(and deliver on time) or get sacked. I wouldn't want to venture out of my depth regarding Indian politics or bureaucracy but political will and good execution are vital for any major defence projects, imho.

Well simply ask if they will get more votes and political support on building a jet engine or a massive high speed rail network ? His supporters and detractors both like to paint him as some strong man /dictator when all every indian PM has been is part of the buerocracy and having nukes makes you more "secure" in the mind.

 

[kakaliam2]

I remember, reading online, Indians boasting Modi for his approach towards the country's "neglected" defence industry. I thought he brought some urgency to the indigenous defence programs?

I'm not a fan of Erdogan but he takes this business very seriously. It's either you deliver(and deliver on time) or get sacked. I wouldn't want to venture out of my depth regarding Indian politics or bureaucracy but political will and good execution are vital for any major defence projects, imho.

It's a problem of larger system. You can't simply fire a Government Employee. The Indian Judiciary which often lives in Ivory Towers sides with David even if he is wrong.

Cut the bureaucracy and for the poor level of Manufacturing and lack of ancillary ecosystem we have now 4 SSBNs and the next 13,000-Ton one already in Construction. That is what happened since that program is directly under PMO.

As far as Jet Engine is concerned there are improvements. The New Engine that is now called K9* will be mated with a New Afterburner with weight of only some 110Kg heavier. They didn't sit idle. Weight was brought down from 1500 Kg to some ~1140 Kg for same performance as F404. The next plan for them is to do the same thing GE did- Upgun to F414 class.

 

[Spitfire9]

It's a problem of larger system. You can't simply fire a Government Employee. The Indian Judiciary which often lives in Ivory Towers sides with David even if he is wrong.

Cut the bureaucracy and for the poor level of Manufacturing and lack of ancillary ecosystem we have now 4 SSBNs and the next 13,000-Ton one already in Construction. That is what happened since that program is directly under PMO.

As far as Jet Engine is concerned there are improvements. The New Engine that is now called K9* will be mated with a New Afterburner with weight of only some 110Kg heavier. They didn't sit idle. Weight was brought down from 1500 Kg to some ~1140 Kg for same performance as F404. The next plan for them is to do the same thing GE did- Upgun to F414 class.

Sure, move onto a 100kN engine post developing a ~80kN afterburning K9-based engine. I suggest focus on getting a result on an engine for Tejas Mk1A ASAP is what is important. Mk1A needs an alternative to F404 for reliability of supply reasons, doesn't it?

 

[Nilgiri]

https://twitter.com/i/web/status/1875204239712305255

 

[TR_123456]

https://twitter.com/i/web/status/1875204239712305255

underwent successful testing at a Russian facility.

Why Russian,why not Indian?

 

[kakaliam2]

underwent successful testing at a Russian facility.

Why Russian,why not Indian?

Its flying test bed. Its not something that can be built casually like a Ground based Wind tunnel facility. You need a 4-Engine plane to fly that thing. The inner circle talk is that no one is coming forward to give that. You only have 3 companies able to do that now- Boeing, Airbus and Illyushin, There was also a talk that Russians said "Why build yours when you can have mine?" to already miserly bureaucrats who seem to not understand the hidden chokehold techniques add on to wanting to keep the gravy train running. Bureaucrats see 50M$ vs Billions of dollars only in short term but they aren't smart enough to see snowballing of said subscription model in long term.

 

[hugh]

Its flying test bed. Its not something that can be built casually like a Ground based Wind tunnel facility. You need a 4-Engine plane to fly that thing. The inner circle talk is that no one is coming forward to give that. You only have 3 companies able to do that now- Boeing, Airbus and Illyushin, There was also a talk that Russians said "Why build yours when you can have mine?" to already miserly bureaucrats who seem to not understand the hidden chokehold techniques add on to wanting to keep the gravy train running. Bureaucrats see 50M$ vs Billions of dollars only in short term but they aren't smart enough to see snowballing of said subscription model in long term.

Is a 4 engine aircraft a must in this day and age? Can a twin-engine aircraft be utilized for this purpose? A turbofan engine with a modern FADEC combined with your engine(assuming similar thrust levels) should be able to coast through even in case of an engine shutdown? No?

If that is a hard no, then we(Turkey) have a serious problem for KAAN's engine test campaign as well.

 

[kakaliam2]

Is a 4 engine aircraft a must in this day and age? Can a twin-engine aircraft be utilized for this purpose? A turbofan engine with a modern FADEC combined with your engine(assuming similar thrust levels) should be able to coast through even in case of an engine shutdown? No?

If that is a hard no, then we(Turkey) have a serious problem for KAAN's engine test campaign as well.

The French seem to have used Rafale prototype itself as flying test bed. Obviously the engines are closely coupled hence even if one fails the other would be enough to make it back to base. RR seems to use 747. GE also uses 747. Russia and China uses the Illyushin il-78. The problem with French approach was that they first built the plane- which was twin engine. So you could later swap one engine with their own to test it. Here we had to purpose build the Fighter or make adjustments to Tejas if we were to put in Kaveri in that and test it. But obviously since its a single-engine fighter it doesn't make sense. We had two engine Fighters like Mig-29 and Su-30, but Kaveri dimensions doesn't suit them. The talk is that they are looking for Mig-29 to modify it and fly the Kaveri.

If we had a hypothetical twin engine Tejas with F404, the French approach would have been replicable. But that is not possible as of now.

 

[TR_123456]

If that is a hard no, then we(Turkey) have a serious problem for KAAN's engine test campaign as well.

No its not and why would we have a problem if so?
We have the Turkish Airlines,it would provide if needed.
Think about it!

 

[Nilgiri]

underwent successful testing at a Russian facility.

Why Russian,why not Indian?

Not enough investment in the program to convert say an IAF Il-76 into a testbed.

It is well within Indian capacity to have its own flying test bed

The program (and its predecessors that led to this one) has been criminally underfunded over long time compared to what has been expected out of it.

I suppose at this point GTRE has a core set of engineers at least to finish job for this dry thrust application into the UAV....and also to make good use of the collaboration with GE coming up.

 

[Nilgiri]

Is a 4 engine aircraft a must in this day and age? Can a twin-engine aircraft be utilized for this purpose? A turbofan engine with a modern FADEC combined with your engine(assuming similar thrust levels) should be able to coast through even in case of an engine shutdown? No?

If that is a hard no, then we(Turkey) have a serious problem for KAAN's engine test campaign as well.

4 engine platform is best because you are impacting way less by switching one engine out....and tends to fit within existing regulations no problem.

2 engine could potentially be used, but it would put the pilots under higher stress given the differential thrust problem combined with concentrated wingloading that 1 engine/wing has. i.e you will purposely be putting the aircraft in emergency environment with full counter-yaw etc... so to speak multiple times during a test (as you test all engine operating ranges with varying thrust, including shutoff and restart etc).

Its basically best to have a regular (already optimised/reliable to aircraft design) engine operating on one side at all times to mitigate all that as far as possible....or have a trijet (tail engine on centre line to begin with that makes the test engine volume to begin with) that makes the whole issue symmetric. FAR regulations and type certificate process (for test exceptions) mostly iirc have this as the guiding principle....otherwise things get too intense too easily.

 

[Spitfire9]

underwent successful testing at a Russian facility.

Why Russian,why not Indian?

Indian government did not want to invest in test infrastructure - wind tunnels, high altitude test chambers, flying test bed etc. 10 years ago many Airbus A340 were available for peanuts (i heard $25 million each) because airlines retired them prematurely but Indian government did not take the opportunity to buy a couple.

The air intakes for Tejas Mk2 were recently tested in France because India lacked the facilities (and expertise?) to do so.

PS IIRC India has recently decided to invest in a high altitude test chamber.

 

[kakaliam2]

The information is gathered from other forums and credit to Original author*
Some of the technologies in Jet Engine and how far DRDO has come-

1. Single Crystal Blades: India’s DRDL developed DMS3 SC in 2003, but it wasn’t up to the high-performance standards required for advanced turbine engines. By 2013, India developed DMS4 SC, a 4th-generation superalloy, which shows slightly better performance than CMSX-10, a third-generation American alloy. The DMS4 SC demonstrated improved creep resistance, making it better suited for high-temperature environments. Although SC blades are now common in modern engines, Kaveri still uses directionally solidified (DS) blades, primarily because redesigning the engine to accommodate SC blades would require significant changes to the entire design—something that is not feasible for the older Kaveri platform
2. Electron Beam Melting (EBM): EBM is a technology India has developed for making cooling channels in high-temperature engine components. Although the specifics are largely unknown, Kaveri Dry engine tests in Russia suggest a high level of competence. The main hurdle, though, lies in EBM machinery, which remains costly and difficult to import due to international restrictions. Access to state-of-the-art equipment is still a limiting factor, but progress is evident in cooling channel development for India's engines.
3. Electron Beam Physical Vapor Deposition (EBPVD): India has mastered EBPVD technology, which is crucial for applying thermal barrier coatings to SC blades, as seen in the Shakti Turboshaft engine. India has its own EBPVD machine, but its capacity is still relatively small-scale. While the technology exists, scaling it up for a more advanced engine like Kaveri is limited by the scale of machinery available. India’s progress, however, shows that the country isn’t lacking expertise in EBPVD.
4. Powder Metallurgy: India has established the capability to use powder metallurgy for manufacturing certain parts, but the technology is still maturing. The main issue is achieving the right level of porosity and the correct balance of material properties for advanced jet engines. While the process is available, it hasn’t yet met the high standards required for the most demanding components in an engine like Kaveri.
5. Blisk Manufacturing: India has proven its ability to manufacture advanced components like Blisks through MIDHANI, which produces high-performance titanium alloys and other advanced materials. HAL is also working on an ultra-large forging press, which will be essential for producing large and complex parts for future engines. The technology for manufacturing Blisks is already in place, and with continued investment, India can meet future demand for these high-performance components.
6. Polymer Matrix Composite (PMC) Ducts: India has transitioned to using PMC ducts in place of metal-based ducts, which offer significant weight savings. However, the manufacturing process still relies on resin infusion, an older method. Moving to more advanced techniques like Automated Fiber Placement (AFP) could improve precision and efficiency in producing these composite ducts. The key challenge remains the availability of machinery to fully transition to these more advanced composite manufacturing techniques.
7. FADEC: The development of Full Authority Digital Engine Control (FADEC) is constrained by India’s reliance on foreign semiconductor technology. However, the proposal to upgrade SCL Mohali to produce 28nm chips could solve this issue. Once this upgrade is completed, India will be able to produce indigenous chips for FADEC, leading to greater control over engine management and a reduction in dependency on foreign technology.
8. Distortion-Tolerant Fan: The Kaveri engine has seen a redesign of its fan, which now achieves a 30:1 compression ratio, bringing it in line with engines like the F414. This increase in compression ratio also enhances the engine’s ability to tolerate flow distortion, meaning it can handle air coming from serpentine intakes and withstand supersonic oblique compression shocks. These features are essential for stealth and advanced operational capabilities, which the Kaveri redesign addresses effectively.

In conclusion, while India’s Kaveri engine has benefited from advancements in key technologies like single crystal alloys, EBPVD, cooling channels, and distortion-tolerant fans, challenges remain in scaling up these capabilities, particularly in advanced manufacturing technologies and access to high-performance machinery. The Kaveri engine still uses older technologies like DS blades due to design constraints, but GTRE developments made throughout its lifecycle have laid the foundation for future advancements. The focus now is on scaling up these technologies and reliably producing them and it is why they are seeking a partner.

 

[Spitfire9]

Is a 4 engine aircraft a must in this day and age? Can a twin-engine aircraft be utilized for this purpose? A turbofan engine with a modern FADEC combined with your engine(assuming similar thrust levels) should be able to coast through even in case of an engine shutdown? No?

If that is a hard no, then we(Turkey) have a serious problem for KAAN's engine test campaign as well.

I imagine that a 4 engine aircraft is far better suited to being a flying testbed than a 2 engine testbed.

- engines on A340/B747 provide far more thrust (200kN+) than any engine intended for use on a fighter
- I imagine it is easier to convert a larger aircraft into a testbed, given it has far more internal space
- with podded engines, A340/B747 are easier to modify to accommodate the test engine than an airframe with engines accommodated in the fuselage
- loss of thrust from an inboard engine under test will cause less yaw
- loss of thrust from the test engine has no effect on fight safety
- better suited to test engines with limited thrust (testbed does not need thrust from the test engine to fly normally)

Please do correct me if I am wrong.