GTRE Kaveri Engine

_Anonymous_ said:
Can you elaborate on this ? Why exactly do you think Kaveri will be superior to the GE TF ? Is it coz it will be flat rated as opposed to the GE TF ? Besides what about the fact that the Kaveri was supposed to be a VCE - Variable Cycle Engine ? Are we still aiming for it to be VCE ? What're your views ? @Gautam
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Pls go thru the attached document about how thrust detiriorates with increase in temp. This will tell you as to what Kaveri with 81Kn will be superior to F404 with 89KN. Indian Standard Atmosphire is ISA+20 at 150Feet elevation. This means a reduction of nearly 10% thrusrreduction to the so called ISA sea level thrust. F404 thrust is for that condition while Kaveri is for Indian conditions. Thats whay I say that if Kaveri is certified in same category as F404, its equivalent thurst will be nearly 91KN.

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vstol Jockey said:
Pls go thru the attached document about how thrust detiriorates with increase in temp. This will tell you as to what Kaveri with 81Kn will be superior to F404 with 89KN. Indian Standard Atmosphire is ISA+20 at 150Feet elevation. This means a reduction of nearly 10% thrusrreduction to the so called ISA sea level thrust. F404 thrust is for that condition while Kaveri is for Indian conditions. Thats whay I say that if Kaveri is certified in same category as F404, its equivalent thurst will be nearly 91KN.

View attachment 39135
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Can change in fuel or development of new fuel mixture add to increased thrust, that will compensate the increased weight issue?
 
Heroforever said:
Gautam bro, everything is fine but what is the service life of Kaveri engine according to you?
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It's a bit fuzzy. There are no direct answers. I read somewhere that the equiaxed blades with no TBC would have a lifespan of ~500 hrs. DMS4 SC blades can supposedly do 1000+ hrs. I don't know if this 1000+ number is with or without TBC. If we are going for a Niobium/Columbium alloy nozzle then those will need an overhaul at around 1000 hrs too.
vstol Jockey said:
It appears to me that we have done some significant advance in Hot core tech. I read an article in which we have created a CMC core with a temprature of over 1700*C or 1973K. This seems to have unnerved USA in forcing more controls on us.
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Redux of the PARAM supercomputer story. Could you share that article.

I didn't think our R&D efforts into CMCs had gone far enough for us to make engine core components out of it. Here is a comparative chart I made of the performance achieved by Kaveri K9 vs. performance expected from AMCA's engine:
Kaveri vs. AMCA engine comparison.jpg

If we have gone close to 1900-2000 K, then AMCA's engine is very much within reach. 1900-2000 K is 5th gen engine territory. If this is true, then engine collab with foreign OEM might not be needed at all.
 
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@Gautam sir can you please through light on gamma Ti Al alloy development in our country. Upto which stage we have reached. As equiaxe compressor stages add weight and add lot of inertia to compressor stages, we finally need to move away these stages with lighter materials. What are our possible options in addition to Powder forge gamma Ti Al.
 
The Tashkent files said:
@Gautam sir can you please through light on gamma Ti Al alloy development in our country. Upto which stage we have reached.
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We are doing pretty good with Titanium-Aluminum systems actually. We have sizable domestic production of aerospace grade Ti-6Al-4V alloy produced using vacuum melting. gamma-TiAl is very much doable is the same facility that we use for Ti-6Al-4V alloy.

We also have active production of SiAlON based ceramics & CERMETS. We have recently set up nano-coating capability for 2D & 3D TiAlSiN nanomaterials.
The Tashkent files said:
As equiaxe compressor stages add weight and add lot of inertia to compressor stages, we finally need to move away these stages with lighter materials. What are our possible options in addition to Powder forge gamma Ti Al.
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GTRE/DMRL favors Nickel based super-alloys based single crystal for turbine blades.

For tubes, combustion chambers, nozzles etc. they have tested NiMoNIC or NiCrOM alloys like A286, 11Cr-9Ni & 12Cr-10Ni alloy grades. They are also testing some Ti-Al grades.
 
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Dry kaveri that is going to be used in ghatak, it's weight is 1180 kg, and that's without afterburner.
So, how much afterburner if it is added might increase the weight?
 
Heroforever said:
Dry kaveri that is going to be used in ghatak, it's weight is 1180 kg, and that's without afterburner.
So, how much afterburner if it is added might increase the weight?
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A dry engine has roughly same length as the afterburning engine. The increase in length is due to the con-div nozzles. The dry engine has a jet pipe behind which allows for the air to be mixed with bypass air to reduce the jet pipe tempratures and exhaust gas temperatures. In Afterburner section, the same jet pipe is fitted with the afterburner nozzles which spread fuel to this mixture of bypassed air and the air coming from the combustion chamber. So, IMHO, there will be an increase of under 100kgs to the weight but we are already talking of the weight being reduced to 1000kgs from present 1180 kgs. This will be done after the trials in Russia. The wet Kaveri should be around 1150 kgs with Afterburner after the weight reduction. This compares very well with GE F404 which has a weight of 1072 kgs for the Indian Variant. Plus a slight increase in the weight will enhance the performance of Tejas as the engine is shorter than F404 in length and the CG of this engine will in crease the instability of Tejas which in turn might enhance its performance.
 
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Gautam said:
It's a bit fuzzy. There are no direct answers. I read somewhere that the equiaxed blades with no TBC would have a lifespan of ~500 hrs. DMS4 SC blades can supposedly do 1000+ hrs. I don't know if this 1000+ number is with or without TBC. If we are going for a Niobium/Columbium alloy nozzle then those will need an overhaul at around 1000 hrs too.

Redux of the PARAM supercomputer story. Could you share that article.

I didn't think our R&D efforts into CMCs had gone far enough for us to make engine core components out of it. Here is a comparative chart I made of the performance achieved by Kaveri K9 vs. performance expected from AMCA's engine:
View attachment 39306
If we have gone close to 1900-2000 K, then AMCA's engine is very much within reach. 1900-2000 K is 5th gen engine territory. If this is true, then engine collab with foreign OEM might not be needed at all.
Click to expand...
God Forbid ! Hope this isn't the reason we're not going in for the JV for the TF of AMCA Mk-2 . For if that's the case , this will take another 4-5 years to be tested & certified post which we construct the TF , test & certify it which would be another 8-10 years . Where's the time for all that ? IIRC , Kadi Ninda issued instructions to the MoD to expedite the negotiations for the JV within a year in early 2021 . We're now in 2025.
 
vstol Jockey said:
A dry engine has roughly same length as the afterburning engine. The increase in length is due to the con-div nozzles. The dry engine has a jet pipe behind which allows for the air to be mixed with bypass air to reduce the jet pipe tempratures and exhaust gas temperatures. In Afterburner section, the same jet pipe is fitted with the afterburner nozzles which spread fuel to this mixture of bypassed air and the air coming from the combustion chamber. So, IMHO, there will be an increase of under 100kgs to the weight but we are already talking of the weight being reduced to 1000kgs from present 1180 kgs. This will be done after the trials in Russia. The wet Kaveri should be around 1150 kgs with Afterburner after the weight reduction. This compares very well with GE F404 which has a weight of 1072 kgs for the Indian Variant. Plus a slight increase in the weight will enhance the performance of Tejas as the engine is shorter than F404 in length and the CG of this engine will in crease the instability of Tejas which in turn might enhance its performance.
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Those afterburner sections contain actuators as well as heat resistant panels that are applied on nozzle section to handle heat, I think it would go above 100 kg prediction.
 
Heroforever said:
Those afterburner sections contain actuators as well as heat resistant panels that are applied on nozzle section to handle heat, I think it would go above 100 kg prediction.
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No It will not. The divergent nozzle set up ensures that you do need additionional strengthening of the after burner section. Infact the divergent nozzle reduces the pressure and increases the the velocity to allow for supersonic speeds. P1V1+P2V2. So if you reduce the pressure in a Benouli system, the velocity increases. Please read about Gas Laws.
 
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vstol Jockey said:
Kaveri with 51KN dry and 81KN wet is superior to GE F404 with 89KN thrust. The present ones fitted in LCA Mk1 are 1072 kgs in weight. If the weight can be brought down to 1100kgs for Kaveri, it will outdo F404 anyday.
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The 51/81 KN version of Kaveri is no more.

The goal now is 45/74 KN.

So Kaveri is not even being developed for the current production of Mk1As. And GTRE's main mandate for now is IUSAV and FUFA, hence the lower thrust.

Coming to your other posts:
A 90 KN version of Kaveri is a future option and a 110 KN new engine is backup for AMCA in case negotiations fail. But neither can be pursued independently without F414-related production technologies. We still don't have blisk, bling or laser drilling tech for example. All of these have to come from the US over the next 5 years. Or we have to take another 10 years to develop everything from scratch before starting one.

So even if we have developed CMC, we can't machine and coat it without F414 tech. That's where we are right now.
 
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