ADA Tejas Mark-II/Medium Weight Fighter

Okabe Rintarou

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CMC SiC for Hypersonic vehicles are already developed
The CMC you are talking about have a Silicon Carbide matrix, but are reinforced with Carbon fiber, not Silicon Carbide fiber. Such older CMC tech is already in use in GE-414-400 engines (the non EPE GE-414) as well as F100 engines for F-16. Its primarily used in the nozzle flaps.

The kind we need is Silicon Carbide matrix reinforced by Silicon Carbide fiber.

Work is required to first produce SiC fibers of desired quality, followed by proper fabrication of SiC-SiC composite. I did some digging and found this recent (2016) patent by DRDO for a melt spinning-curing-pyrolisis process for making SiC fibers. A cursory glance at the numbers tells me that we have barely achieved 1st generation SiC fibers.
DRDO patent: https://www.quickcompany.in/patents/a-process-for-the-preparation-of-silicon-carbide-ceramic-fibers
GE is beyond 4th generation SiC fibers right now. And their 3rd generation SiC fiber based CMC are used in non-rotating parts of CFM-56 LEAP engines. The first generation we have achieved does not even have completely crystalline microstructure. Subsequent work should focus on removal of Si-O phases and then reduction in amount of carbon phase precipitating at grain boundaries as well as increase in size of grains. Aim is to achieve a near-stoichiometric crystal microstructure with large grains. This will give us 3rd generation SiC fibers. For further improvements to creep resistance, subsequent generations have focused on even larger grain sizes and a microstructure almost free from pores and impurities. Boron Nitride coatings are also applied on the fibers to prevent unrestricted crack propagation from the matrix into the fiber. In India, none of this is done yet. All we have managed till now is an SiC fiber with a microstructure that has a largely amorphous structure, which is against the basic principle of why any kind of fiber is used in any kind of reinforcement.

Indigenous technologies have been demonstrated for
synthesis of PDMS, PCS, PIP process for fabricating C/SiC
composites and also to develop test prototypes have been
demonstrated. The mechanical and thermal properties of the
indigenous material are found to be on par with the materials
developed elsewhere. The indigenous technology initiative
efforts have also resulted in demonstration of the SiC fibre
technology. The scale down rocket nozzle divergent cone is
expected to have much better performance compared to the
C/Phenolic nozzles being used in the present rocket motors.
The PIP technology has also opened a path to develop C/
SiC composites based hot structures to replace the ablative
material-based systems. The C/SiC composite process would
become basis to fabricate SiC/SiC composites once SiC fibre
process get matured.
Exactly. Once the SiC fiber process gets matured. Its not mature yet, for reasons I mentioned above. First they need to mature that process, then they'll reach the starting line for SiC-SiC composites, i.e. employing SiC-SiC components in nozzles and then slowly improve it to apply in stators (vanes). GE already uses these things in commercial engines. Has been doing so for a while. We will also need to work on the environmental barrier coatings. Although the experience of DRDO with C/SiC CMC will help, GE also went through C/SiC stage before reaching to where it is now. DRDO has a long path ahead and the least government can do is aid them by creating a National Mission on Gas Turbine Technologies. We need clear goals, not the current ad-hoc approach, if we want to catch up to GE.

Is it possible to use in indigenous engine blades ,
Why not by applying environment barrier coating it can be used.
Not that simple. I highlighted the challenges to achieving CMC for non-rotating parts. In addition to those challenges, CMC in turbine blade adds the additional challenges of sustaining high cycle fatigue due to vibrations of blades, low cycle fatigue in the root that dovetails with the disk, centrifugal forces requiring better creep resistance, rubbing of rotating blade tips with turbine shroud, etc. Creep resistance needs to be much better. There is a reason GE is celebrating the achievement of rotating CMC parts.
 

Karthi

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The CMC you are talking about have a Silicon Carbide matrix, but are reinforced with Carbon fiber, not Silicon Carbide fiber. Such older CMC tech is already in use in GE-414-400 engines (the non EPE GE-414) as well as F100 engines for F-16. Its primarily used in the nozzle flaps.

The kind we need is Silicon Carbide matrix reinforced by Silicon Carbide fiber.

Work is required to first produce SiC fibers of desired quality, followed by proper fabrication of SiC-SiC composite. I did some digging and found this recent (2016) patent by DRDO for a melt spinning-curing-pyrolisis process for making SiC fibers. A cursory glance at the numbers tells me that we have barely achieved 1st generation SiC fibers.
DRDO patent: https://www.quickcompany.in/patents/a-process-for-the-preparation-of-silicon-carbide-ceramic-fibers
GE is beyond 4th generation SiC fibers right now. And their 3rd generation SiC fiber based CMC are used in non-rotating parts of CFM-56 LEAP engines. The first generation we have achieved does not even have completely crystalline microstructure. Subsequent work should focus on removal of Si-O phases and then reduction in amount of carbon phase precipitating at grain boundaries as well as increase in size of grains. Aim is to achieve a near-stoichiometric crystal microstructure with large grains. This will give us 3rd generation SiC fibers. For further improvements to creep resistance, subsequent generations have focused on even larger grain sizes and a microstructure almost free from pores and impurities. Boron Nitride coatings are also applied on the fibers to prevent unrestricted crack propagation from the matrix into the fiber. In India, none of this is done yet. All we have managed till now is an SiC fiber with a microstructure that has a largely amorphous structure, which is against the basic principle of why any kind of fiber is used in any kind of reinforcement.


Exactly. Once the SiC fiber process gets matured. Its not mature yet, for reasons I mentioned above. First they need to mature that process, then they'll reach the starting line for SiC-SiC composites, i.e. employing SiC-SiC components in nozzles and then slowly improve it to apply in stators (vanes). GE already uses these things in commercial engines. Has been doing so for a while. We will also need to work on the environmental barrier coatings. Although the experience of DRDO with C/SiC CMC will help, GE also went through C/SiC stage before reaching to where it is now. DRDO has a long path ahead and the least government can do is aid them by creating a National Mission on Gas Turbine Technologies. We need clear goals, not the current ad-hoc approach, if we want to catch up to GE.



Not that simple. I highlighted the challenges to achieving CMC for non-rotating parts. In addition to those challenges, CMC in turbine blade adds the additional challenges of sustaining high cycle fatigue due to vibrations of blades, low cycle fatigue in the root that dovetails with the disk, centrifugal forces requiring better creep resistance, rubbing of rotating blade tips with turbine shroud, etc. Creep resistance needs to be much better. There is a reason GE is celebrating the achievement of rotating CMC parts.

don't worry next generation SiCs are under various developmental stages.

Development of C-SiC composite for jet vanes of missiles.png


Development of C-SiC composite for jet vanes of missiles.

High temperature low density closed cell SiC foam..png


Silicon carbide fiber, High temperature low density closed cell SiC foam.

silicon carbide.png


Silicon Carbide Foam From Polycarbosilane, High temperature low density closed cell SiC foam.


/ /////////////////

I will post about when I get time & mood
 

Okabe Rintarou

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don't worry next generation SiCs are under various developmental stages.

View attachment 88601

Development of C-SiC composite for jet vanes of missiles.

View attachment 88602

Silicon carbide fiber, High temperature low density closed cell SiC foam.

View attachment 88603

Silicon Carbide Foam From Polycarbosilane, High temperature low density closed cell SiC foam.


/ /////////////////

I will post about when I get time & mood
These are not next generation. These are the ones I explained. These are the same Carbon fiber reinforced SiC from the same DRDO lab that was involved in that patent I linked above. You can conduct your own analysis later on to verify that the info I gave is most recent available.
 

Ajax01

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These are not next generation. These are the ones I explained. These are the same Carbon fiber reinforced SiC from the same DRDO lab that was involved in that patent I linked above. You can conduct your own analysis later on to verify that the info I gave is most recent available.
If you are talking about Carbon fibre reinforced Silicon Carbide composites it has been made in 2012 itself by DMRL and IIT KGP
 

Okabe Rintarou

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If you are talking about Carbon fibre reinforced Silicon Carbide composites it has been made in 2012 itself by DMRL and IIT KGP
No. I am talking about SiC/SiC CMC. Not C/SiC CMC. Please read my first comment on this page. Everybody is getting confused between the two.
 

Ajax01

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No. I am talking about SiC/SiC CMC. Not C/SiC CMC. Please read my first comment on this page. Everybody is getting confused between the two.
I read that but your document attached had 2016 as the initial date of achieving C/Sic. I pointed out that it happened earlier.
 

Okabe Rintarou

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Flying Dagger

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Contradicting each other here. What do @Rajaraja Chola base that claim on?.. Please share the source 1st.

Because we too "have Kaveri", that's issue is what being contested here... EPE doesn't exist, until it actually exists. As I said, let's check again in 2025 if the miracle happens.

Have worked with or have any experience around an engine design? Ever visited a RR or GE engine site ?

F414 is actually developed from F404 enlarged and more efficient so if they offer improvement over it I'll rather take their word. New fan and compressor components will improve the performance and thrust.

Miracles are needed for those who don't believe in hardwork And facts.

@Rajaraja Chola the pdf you got from GE site merely offer the product but it's not yet ordered so not built in physical form. It's been hanging since a decade.

No company will invest millions of dollar to build a product for which there are no customer.
 

Rajaraja Chola

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Have worked with or have any experience around an engine design? Ever visited a RR or GE engine site ?

F414 is actually developed from F404 enlarged and more efficient so if they offer improvement over it I'll rather take their word. New fan and compressor components will improve the performance and thrust.

Miracles are needed for those who don't believe in hardwork And facts.

@Rajaraja Chola the pdf you got from GE site merely offer the product but it's not yet ordered so not built in physical form. It's been hanging since a decade.

No company will invest millions of dollar to build a product for which there are no customer.

https://www.google.com/amp/s/news.y...-powerful-engine-upgrade-navys-043000697.html

As reported by DefenseNews, the U.S. Navy has awarded to General Electric (GE)a $114.8 million contract aimed to install new engines on the service F/A-18 Super Hornet and EA-18G Growler aircraft.

The fixed-price contract provides procurement funding for 28 Lot 20 and 21full-rate production F414-GE-400 engines.

Noteworthy the new engine could be the so called General Electric’s enhanced performance engine (EPE), that would increase the F414-GE-400’s power output from 22,000 lbs to 26,400 lbs. EPE development commenced in 2009 and features several improvements over the standard F414-GE-400, including greater resistance to foreign object damage, reduced fuel burn rate, and potentially increased thrust of up to 20%.

As explained by Department of Defense (DoD), the work will be carried out in several locations: Lynn, Massachusetts, Hooksett, New Hampshire, Rutland, Vermont and Madisonville, Kentucky. Naval Air Systems Command (NAVAIR), at Naval Air Station (NAS) Patuxent River, Maryland is overseeing the project, that is due to be completed in Feb. 2019.

EPE is one of the several improvements that could feature the Advanced Super Hornet.
 

Flying Dagger

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https://www.google.com/amp/s/news.y...-powerful-engine-upgrade-navys-043000697.html

As reported by DefenseNews, the U.S. Navy has awarded to General Electric (GE)a $114.8 million contract aimed to install new engines on the service F/A-18 Super Hornet and EA-18G Growler aircraft.

The fixed-price contract provides procurement funding for 28 Lot 20 and 21full-rate production F414-GE-400 engines.

Noteworthy the new engine could be the so called General Electric’s enhanced performance engine (EPE), that would increase the F414-GE-400’s power output from 22,000 lbs to 26,400 lbs. EPE development commenced in 2009 and features several improvements over the standard F414-GE-400, including greater resistance to foreign object damage, reduced fuel burn rate, and potentially increased thrust of up to 20%.

As explained by Department of Defense (DoD), the work will be carried out in several locations: Lynn, Massachusetts, Hooksett, New Hampshire, Rutland, Vermont and Madisonville, Kentucky. Naval Air Systems Command (NAVAIR), at Naval Air Station (NAS) Patuxent River, Maryland is overseeing the project, that is due to be completed in Feb. 2019.

EPE is one of the several improvements that could feature the Advanced Super Hornet.
Please read carefully what you have posted. Everything is could be...when it comes to EPE It's been going on since More than a decade . Unless money is marked by a customer they won't built it.

But yes chances are likely USN will ask for it and there are lot of customers using GE F414 they may also opt for upgraded engine but not right now.
 

Spitfire9

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https://www.google.com/amp/s/news.y...-powerful-engine-upgrade-navys-043000697.html

As reported by DefenseNews, the U.S. Navy has awarded to General Electric (GE)a $114.8 million contract aimed to install new engines on the service F/A-18 Super Hornet and EA-18G Growler aircraft.

The fixed-price contract provides procurement funding for 28 Lot 20 and 21full-rate production F414-GE-400 engines.
Misleading story. If you read the defensenews report, it is clear that the engines are 22,000lb thrust.

Noteworthy the new engine could be the so called General Electric’s enhanced performance engine (EPE), that would increase the F414-GE-400’s power output from 22,000 lbs to 26,400 lbs.
No it couldn't. Fake news.
 

Bleh

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What will be the approx Combat radius of MWF?
Anyone with rough calculations?
IMG_20201126_092459.jpg

4700lt fuel in droptanks here, another 4200lt (3388kg) internally.

Assuming some paylosd of 2×ASM, 2×BVRAAM, 2×CCM in the leftover it should comfortably reach 3000km... given LCA Tejas can be ferried about 2000km at less than 2/3rd that fuel, but with inferior aerodynamic & not drag-optimised droptanks.
 
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[email protected]

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No. I am talking about SiC/SiC CMC. Not C/SiC CMC. Please read my first comment on this page. Everybody is getting confused between the two.
Both crytalline SiC fiber/SiC CMC and carbon fiber/SiC CMC have been developed in NAL through Chemical Vapour Infiltration (ICVI) process way back in 2009 itself.
 

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Bleh

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MWF closeup...

EtmRUk8VIAA9G9C.jpeg
ADA's most likely gonna be using this refueling-probe retraction mechanism of Jaguar, on the Tejas Mark2... It's the simplest one of all the jets we make in India & takes up least internal space (a major factor in MWF's case). The positioning, as well as angle are an exact match in both. 😅😅

 
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