Indian Military News, Reports, Data, etc.

_killuminati_ said:

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This article doesn't seem the best peer-reviewed article.
What reasons were given for failing the program? The published 6.9 thrust/weight ratio isn't great, but surely an underpowered fighter in quantity with domestic components is better than a fighter that can barely be produced?

There are probably more issues than that. The engine lifetime might not be up to snuff.
Unfortunately these things only get fixed with continued tests and actual production. I think the Soviet AL-31 originally had a lifetime of like 100 hours. Yes it was that bad. Now the Russian AL-41 has a lifetime of over 4000 hours.

gelgoog said:

There are probably more issues than that. The engine lifetime might not be up to snuff.
Unfortunately these things only get fixed with continued tests and actual production. I think the Soviet AL-31 originally had a lifetime of like 100 hours. Yes it was that bad. Now the Russian AL-41 has a lifetime of over 4000 hours.

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It would seem that the IAF's decision to cancel the program has greatly hindered, or at least not helped, further domestic development of jet engines?

valysre said:

This article doesn't seem the best peer-reviewed article.
What reasons were given for failing the program? The published 6.9 thrust/weight ratio isn't great, but surely an underpowered fighter in quantity with domestic components is better than a fighter that can barely be produced?

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It depends on what kind of underpower it is. In LCA's case, an underpowered fighter is as usefull as nothing. We know J-20 with WS-10 is underpowered, but that is not crippling any performance including super-cruise except having to use afterburner (instead of using dry thrust) to break sound barrier. However, Kaveri's 6.9 is ratio with afterburner compared to F404's 7.8. Its dry ratio would be equally below the requirement, it is an all spectrum short-fall.

I think one can tolerate many things like engine life or fuel consumption, but not the thrust and thrust/weight ratio which determines if the aircraft can fullfill its designed purpose. If I remember correctly, WS-10 in its early adoption had various problems but not the thrust.

There has been many cases that a product became outdated or lost its application when it finally reached its design parameter.

So I think that although the wiki page isn't a peer-reviewed scientific paper, it has told us more than enough as why Kaveri isn't operational and probably never.

It would seem that the IAF's decision to cancel the program has greatly hindered, or at least not helped, further domestic development of jet engines?

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Not really, China has also terminated lots of programs but the knowledge built in those programs were never wasted. They greatly helped later programs for example the terminated J-9 became J-10.

I think IAF did the right thing anyone should do. IAF has every day patrol to do, they can not wait nor can they fly a sub-standard aircraft to face F-16 and JF-17.

valysre said:

This article doesn't seem the best peer-reviewed article.
What reasons were given for failing the program? The published 6.9 thrust/weight ratio isn't great, but surely an underpowered fighter in quantity with domestic components is better than a fighter that can barely be produced?

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You should read about the earlier HAL Marut which had done exactly this (bolded part) - underpowered in quantity with domestic components (upto 70%) - which turned out to be a huge failure.

Kaveri wasn't the first engine India attempted to produce. Earlier, they license-built half of the Bristol Siddeley 701, used on the Gnat and yet another major failure called the HAL Ajeet. Marut development also occurred around a domestic engine that never even made it to the drawing boards.

The major problem with all three HAL products - Tejas, Marut, and Ajeet - was of engines. Underpowered engines. They appeared to have learned nothing from the Ajeet and Marut, repeating the exact same mistake with the Tejas, followed by the exact same consequence of acquiring alternative foreign engines which could not meet the originally planned requirements.

All three aircraft were built around a (yet to exist) domestic engine. That domestic engine never developed. The only progress HAL made is that the Tejas may be able to meet it's operational requirements with a foreign engine, but even that is debatable.

Overly ambitious. Engine development capacity is simply not there, even after license-built foreign engines. Reverse-engineering capacity not there. Had they chosen to power any of those aircraft with foreign engines from the start, they'd probably have much more success.

gelgoog said:

There are probably more issues than that. The engine lifetime might not be up to snuff.
Unfortunately these things only get fixed with continued tests and actual production. I think the Soviet AL-31 originally had a lifetime of like 100 hours. Yes it was that bad. Now the Russian AL-41 has a lifetime of over 4000 hours.

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The nozzle was, the AL-100 nozzle.

The engine itself was rated for some 1000-2000 hrs. the AL-31FP is 2500 hrs.

Should probably better fit to the closed funny thread from our young Indian fan-boy posted at the PDF:

It is not totally ludicrous since there is a lot of overlap between rocket engines and gas turbines. For example when Korolev wanted an engine for his N-1 lunar rocket, he went to Kuznetsov who was a jet engine manufacturer. And just last year when UEC Saturn needed to manufacture more PD-8 turbofan engines than they had capacity to do, they signed a contract with NPO Energomash to build them hot sections.
A company which can make rocket engines can also make the hot section of a jet engine. The combustion chamber and the high pressure section. And the opposite is also true. A jet engine company can make a rocket engine. The combustion chamber and the turbopumps.

The main issue, I think, is that working with hydrocarbon engines is kind of different than working with hydrogen engines. You need different alloys, coatings, etc. Hydrogen burns cleaner than Kerosene. But at the same time hydrogen is cryogenic and kerosene is not. So I doubt in this case the Indians would have an easy time going about it.

Retiring WTC soldiers are the gifts that keep on giving.

How on earth did the Indian soldiers get pushed into such a strange position? They're on a very steep shore of a lake, how did they get surrounded from both sides? Where did they push in from?