ADA Tejas Mark-II/Medium Weight Fighter

[Kshithij]

So, GTRE made a 110kN engine to avoid making 2 engines separately for AMCA and Tejas MK2? So, ADA decided to make Tejas MK2 a medium level fighter to fully utilise the engine power. Hmmm...........

 

[Prashant12]

One way out would be to use the GE 414 EPE hot engine with 18% more power than the GE 414 INS6.

The 116 kN thrust class GE 414 EPE has a T/W ratio nearly 11:1

 

[Adioz]

One way out would be to use the GE 414 EPE hot engine with 18% more power than the GE 414 INS6.

The 116 kN thrust class GE 414 EPE has a T/W ratio nearly 11:1

This article: http://archive.is/3yV6#selection-1937.0-1937.39 says that the engine is on offer to India.

The article also says that GE 414 EPE will make the Gripen capable of supercruise. Wonder what will it do to the Tejas?

 

[Kshithij]

This article: http://archive.is/3yV6#selection-1937.0-1937.39 says that the engine is on offer to India.

The article also says that GE 414 EPE will make the Gripen capable of supercruise. Wonder what will it do to the Tejas?

The idea of the EPE engine was to get a CMC blade and disk for hot section. They managed to get CMC for cold section but that provides little advantage except for slight weight reduction. The temperature of cold region is significantly low that all blades work well without having to worry about melting. But, they have not been able to get CMC for hot section yet. This is the crucial part and without it, there is no EPE.

As of now, the CMC for hot section appears to be very elusive and the likelihood of that is very low in the near future. So, there will be no EPE engine in Tejas.

 

[sorcerer]

Tamil Nadu to build India’s next generation defence aircraft
The proposal is not only the first time an indigenous military aircraft programme is seeing the involvement of private players, but it is also the first time a defence plane development project is proposed to be executed outside Bengaluru.

The project — to be implemented in Sulur in Coimbatore district which may house the permanent base of the Tejas squadron — marks Tamil Nadu’s first major defence aircraft project.

Read more at:
//economictimes.indiatimes.com/articleshow/64217410.cms?utm_source=contentofinterest&utm_medium=text&utm_campaign=cppst

 

[darshan978]

One way out would be to use the GE 414 EPE hot engine with 18% more power than the GE 414 INS6.

The 116 kN thrust class GE 414 EPE has a T/W ratio nearly 11:1

lol whats hot engine tech.
he think we are illiterate?
i guess he was saying "improved coolling system in HOT SECTION'' of GE-414EPE

 

[Kshithij]

lol whats hot engine tech.
he think we are illiterate?
i guess he was saying "improved coolling system in HOT SECTION'' of GE-414EPE

The EPE is supposed to use CMC blades instead of metal blades. It will provide higher temperature tolerance than rhenium based superalloy including 3rd generation SCB. But that is a distant dream.

 

[Adioz]

The idea of the EPE engine was to get a CMC blade and disk for hot section. They managed to get CMC for cold section but that provides little advantage except for slight weight reduction. The temperature of cold region is significantly low that all blades work well without having to worry about melting. But, they have not been able to get CMC for hot section yet. This is the crucial part and without it, there is no EPE.

As of now, the CMC for hot section appears to be very elusive and the likelihood of that is very low in the near future. So, there will be no EPE engine in Tejas.

AFAIK, GE has tested CMC turbine blades in GE-414. Did not know that EPE was with CMC.

lol whats hot engine tech.
he think we are illiterate?
i guess he was saying "improved coolling system in HOT SECTION'' of GE-414EPE

He meant improved materials in turbine blade, hp compressor and seals.

 

[Kshithij]

AFAIK, GE has tested CMC turbine blades in GE-414. Did not know that EPE was with CMC.


He meant improved materials in turbine blade, hp compressor and seals.

Yes, GE tested it with cold section, not hot. I have mentioned it in my comment. The hot section is the key. Cold section blades are insignificant and only serve to reduce weight

 

[Adioz]

Yes, GE tested it with cold section, not hot. I have mentioned it in my comment. The hot section is the key. Cold section blades are insignificant and only serve to reduce weight

No. Read my post again. I said GE used CMC in turbine blades, not compressor blades.
Read this:-

In the F414 tests, GE validated the temperature tolerance and durability of CMC turbine blades made over 500 duty cycles, allowing for expansive deployment of the advanced manufacturing material in GE’s adaptive cycle combat engine and next-gen commercial engines.

Going from nickel alloys to rotating ceramics inside the engine is the really big jump. But this is pure mechanics,” according to Jonathan Blank, general manager of CMC and advanced polymer matrix composite research at GE Aviation. “The lighter blades generate smaller centrifugal force, which means that you can slim down the disk, bearings and other parts. CMCs allow for a revolutionary change in jet engine design.”

source: http://www.americanmachinist.com/news/ge-notes-success-cmc-engine-rotating-parts

 

[Kshithij]

No. Read my post again. I said GE used CMC in turbine blades, not compressor blades.
Read this:-

source: http://www.americanmachinist.com/news/ge-notes-success-cmc-engine-rotating-parts

The key word here is LPTB or "Low-pressure turbine blades". What is needed is HPTB or "High-pressure turbine blades"

 

[Adioz]

The key word here is LPTB or "Low-pressure turbine blades". What is needed is HPTB or "High-pressure turbine blades"

Where has he written LPTB in the article I quoted?
And if it is indeed so that GE has only used CMC blades in the low pressure turbine, then how do you explain their claim that GE 414 EPE has 20% higher thrust and has a completely re-worked core?

 

[Kshithij]

Where has he written LPTB in the article I quoted?
And if it is indeed so that GE has only used CMC blades in the low pressure turbine, then how do you explain their claim that GE 414 EPE has 20% higher thrust and has a completely re-worked core?

Here I will quote that:

Low-pressure turbine blades in silicon-carbide ceramic matrix composite for F414 adaptive cycle combat engine Lighter rotating parts Advance in CMC for jet propulsion Tests validate temperature tolerance and durability

The hot section saw CMC in static parts only, not rotating ones:

GE stated that introducing rotating CMC components into the hottest, most demanding sections of jet engines “represents a significant technology breakthrough for GE and the jet propulsion industry.”

CMC parts have been adopted successfully for static parts of jet engines, like the high-pressure turbine shroud that CFM International (a GE Aviation joint venture) for the LEAP engines being developed for commercial aircraft (including the Airbus 320neo and Boeing 737 MAX.)

Just do control+F and find the paragraph. Also, quote the lines which say that 20% increase was seen. I could not see any.

I you are saying that EPE is expected to have 20% higher thrust, the you are right. But that is just a project and not reality. It is as completed as an intergalactic space ship project is.

 

[Adioz]

Here I will quote that:


The hot section saw CMC in static parts only, not rotating ones:


Just do control+F and find the paragraph. Also, quote the lines which say that 20% increase was seen. I could not see any.

I you are saying that EPE is expected to have 20% higher thrust, the you are right. But that is just a project and not reality. It is as completed as an intergalactic space ship project is.

The idea of the EPE engine was to get a CMC blade and disk for hot section.

My bad. Missed the LPTB part in that article. Since it is already being used and research is ongoing on using CMC HPTB, we can be sure that it is certainly closer to completion than an intergalactic battleship.

But now that we have had this discussion on CMC in high pressure turbines, let me present you this quote:-

GE had previously considered inserting ceramic matrix composites in the turbine of the F414 Enhanced Engine, but as of early 2014 had resolved to continue using metallic alloy blades.

source: https://www.flightglobal.com/news/a...-interest-in-super-hornet-engine-upgr-434227/

So there are no CMC parts in the GE-414 EPE.


GE-414 EPE's thrust is 18-20% higher than GE-414-400. See the PV:-


BTW, that static parts usage of CMC the article is talking about is not for the GE-414 but the CFM-56's advanced version called "LEAP". It is used in Airbus A320Neo airliners.

 

[Kshithij]

My bad. Missed the LPTB part in that article. Since it is already being used and research is ongoing on using CMC HPTB, we can be sure that it is certainly closer to completion than an intergalactic battleship.

But now that we have had this discussion on CMC in high pressure turbines, let me present you this quote:-

source: https://www.flightglobal.com/news/a...-interest-in-super-hornet-engine-upgr-434227/

So there are no CMC parts in the GE-414 EPE.


GE-414 EPE's thrust is 18-20% higher than GE-414-400. See the PV:-


BTW, that static parts usage of CMC the article is talking about is not for the GE-414 but the CFM-56's advanced version called "LEAP". It is used in Airbus A320Neo airliners.

How will the thrust increase without any change? Will they make the engine bigger and heavier? If the engine becomes heavier, then it is meaningless

 

[darshan978]

cmc tech is still not that mature to use in high pressure turbine blades so GE is just using extra cooling design in EPE engine

 

[Sancho]

@Sancho bhai, still day dreaming about the SE MMRCA tender? Tejas Mk-2 is for meeting original ASQR meant for Tejas? I am sure the original ASQR did not ask for a medium fighter

Sadly you still don't understand the basics. The ASR for Tejas didn't asked for a medium class fighter, but for a specific flight performance. So IAF doesn't care about DRDOs pointless claims about MK2 being medium class, but that it offers the performance an actual air defence fighter should have and not something comparable to strike fighters. They wanted a light class fighter, with the performance that MK2 is promising!

Secondly, meeting the original ASR for Tejas, doesn't mean MK2 can meet the ASR for MMRCAs, because as the recent RFI showed, IAF asks for load capabilities and techs, that Tejas doesn't offer.
So no matter what "Maximum Take Off Weight" MK2 will have, it still won't be comparable to MMRCAs in most fields. That's why IAF for 2 decades is saying, we need a Tejas version that meets it's own goals and more capable MMRCAs above it, to protect the country, not one or the other!
And since I belive that this government will remain in power, a cost-effective MMRCA is sadly the most likely choice, be it SE or TE.

 

[porky_kicker]

Latest design iteration of naval LCA MK2

Most striking is the changes in the canopy shaping

Also is it one piece frameless canopy ?

 

[Sancho]

Latest design iteration of naval LCA MK2

Most striking is the changes in the canopy shaping

Also is it one piece frameless canopy ?

View attachment 25537

The MK1 was based on thw twin seat IAF version (with avionics at the back seat), the MK2 for the navy was always meant to have dedicated single seat versions, so the canopy changes are only in that regard and probably extended, because of the airframe gap behind the cockpit, Tejas MK2 is meant to have.
This pic was shown at AI 2017 and in ADA brochures if I remember correctly.

 

[Saichand K]

Latest design iteration of naval LCA MK2

Most striking is the changes in the canopy shaping

Also is it one piece frameless canopy ?

View attachment 25537

Looks close to Rafale now, especially the canopy shaping and stuff.....