Kaveri Engine

[BON PLAN]

When did your sleep cycle got tied to Indian defence plans? Anyway you are comparing apple and oranges. IN this case GE has to deliver as contract has been signed. Its GE who has promised this year delivery. So the ball is pretty much on GE side. And hence you may want to call your Nato friend to wake you up on the way when they set off to deliver those engines.

I agree India should simply cancel the deal and stop all the long melodrama around Rafale. INvest that money on new Sukhois & LCA. Curent Govt doesnt want to give a single penny extra lest Dassault uses it to reward previous part in power

But your voice is not heard by Indian top brass. Fortunately for India.

 

[AnantS]

But your voice is not heard by Indian top brass. Fortunately for India.

If my voice had been heard, there would not have been endless threads discussing MMRCA. India would have bought Mirage 2000 assembly line years back and should have done with it..

 

[kstriya]

But your voice is not heard by Indian top brass. Fortunately for India.

Your gonna have piles with LCA written on it, you have been involved in so much heated discussion on every thread on DFI to get the Rafale in the context. I sincerely hope you could see the Rafale deal completed but on contrary I see it might not. Best of luck Buddy.

 

[PaliwalWarrior]

I'm sleeping. On my two ears.
Last news is I can sleep until mi august or mid september.

But I know, I know, all has been said about Rafale deal.....

Who told you so ?

Vstol ...,...........................

 

[smestarz]

Cabinte reshuffle amd Parrikar still the defence minister.
So that would make it that whatever Parrikar is doing, Modi does not want to interfere with it.
So.. bye bye Rafale.. welcome LCA AMCA and PAKFA

Who told you so ?

Vstol ...,...........................

 

[BON PLAN]

If my voice had been heard, there would not have been endless threads discussing MMRCA. India would have bought Mirage 2000 assembly line years back and should have done with it..

I agree.
A nice solution for India and for french suppliers at the beginning (after ToT : all can be made in India).

 

[BON PLAN]

Who told you so ?

Vstol ...,...........................

No.
A forumer named PARIKRAMA. Seemed very very well informed in the past...

 

[PaliwalWarrior]

No.
A forumer named PARIKRAMA. Seemed very very well informed in the past...

Yes he seemed very very well informed as he spoke about
300 + rafale deal in tranches along with mii component etc etc and it will be signed soon etc

But since nine of it came out true you are saying very " seemed..."

Past tense

 

[smestarz]

No.
A forumer named PARIKRAMA. Seemed very very well informed in the past...

Was he not tthe one saying the deal would be signed in month of April or May?Thats when NDTv came up with story that Rafale deal would be signed and all Rafale fans were behaving like the lemurs from movie Madagascar when King julien says something? hmm

 

[ersakthivel]

Hope all the news regarding JV for kaveri will bring some concrete development at last,

The Kaveri is a variable-cycle, flat-rated engine and has 13% higher thrust than the GE F-404 engines equipping the LCA prototypes.

Variable cycle means airflow can be varied with temperature, altitude and fuel flow to maintain its thrust at a higher level all the time, a tech that is not in GE 404 or 414,

What it will do is to enhance the performance envelope of Engine in varied climatic conditions of india

Snecma will certify the reliability and maintainability of KAVeri

BILLION EUROS, for only 30% of work of kaveri and we may save many a billion in forex & earn some from exports

What is the thrust of mig 29 engines?
Answer 84 Kn

A hundred odd IAF & navy mig-29 are in service with RD-33 88 KN engines!!!, They are not flat rated like kaveri & neither made especially for indian hot & humid condition!!

SO 100 Mig-29s+ 120 tejas mk1+ mk1 A engines , close to 500 engines over two decades!!

Add to that the export prospects of tejas with no American string or russian string attached engine, economic impact is mind boggling & Tejas project can become a money spinner.

Not to say the boost in performance of AURA UCAV which too will rely on this JV engine.

SO it is a win win deal for every one.

 

[HariPrasad-1]

Hope all the news regarding JV for kaveri will bring some concrete development at last,

The Kaveri is a variable-cycle, flat-rated engine and has 13% higher thrust than the GE F-404 engines equipping the LCA prototypes.

Variable cycle means airflow can be varied with temperature, altitude and fuel flow to maintain its thrust at a higher level all the time, a tech that is not in GE 404 or 414,

What it will do is to enhance the performance envelope of Engine in varied climatic conditions of india

Snecma will certify the reliability and maintainability of KAVeri

BILLION EUROS, for only 30% of work of kaveri and we may save many a billion in forex & earn some from exports

What is the thrust of mig 29 engines?
Answer 84 Kn

A hundred odd IAF & navy mig-29 are in service with RD-33 88 KN engines!!!, They are not flat rated like kaveri & neither made especially for indian hot & humid condition!!

SO 100 Mig-29s+ 120 tejas mk1+ mk1 A engines , close to 500 engines over two decades!!

Add to that the export prospects of tejas with no American string or russian string attached engine, economic impact is mind boggling & Tejas project can become a money spinner.

Not to say the boost in performance of AURA UCAV which too will rely on this JV engine.

SO it is a win win deal for every one.

Ohhh Yes kaveri has demonstrated already a dry thrust in excess of 51 KN. We can bring it to 55 Kn and wet thrust to 90 KN than tejas can be a winner. with some weight reduction and aerodynamic improvement coupled with high thrust engine can make a miracle.

 

[Indx TechStyle]

Was he not tthe one saying the deal would be signed in month of April or May?Thats when NDTv came up with story that Rafale deal would be signed and all Rafale fans were behaving like the lemurs from movie Madagascar when King julien says something? hmm

So, you got to judge his intellectual capability just over one more delay of a deal which has been hanging for years?
I know @PARIKRAMA much before you and trust me, he's professional at defense related affairs.
@HariPrasad-1 may tell you more.

Hope all the news regarding JV for kaveri will bring some concrete development at last,

The Kaveri is a variable-cycle, flat-rated engine and has 13% higher thrust than the GE F-404 engines equipping the LCA prototypes.

Variable cycle means airflow can be varied with temperature, altitude and fuel flow to maintain its thrust at a higher level all the time, a tech that is not in GE 404 or 414,

What it will do is to enhance the performance envelope of Engine in varied climatic conditions of india

Snecma will certify the reliability and maintainability of KAVeri

BILLION EUROS, for only 30% of work of kaveri and we may save many a billion in forex & earn some from exports

What is the thrust of mig 29 engines?
Answer 84 Kn

A hundred odd IAF & navy mig-29 are in service with RD-33 88 KN engines!!!, They are not flat rated like kaveri & neither made especially for indian hot & humid condition!!

SO 100 Mig-29s+ 120 tejas mk1+ mk1 A engines , close to 500 engines over two decades!!

Add to that the export prospects of tejas with no American string or russian string attached engine, economic impact is mind boggling & Tejas project can become a money spinner.

Not to say the boost in performance of AURA UCAV which too will rely on this JV engine.

SO it is a win win deal for every one.

Absolutely, French too are right at their place.
I say pay high price for Rafael if we can get JV for engine and QRSAM from them. But @smestarz won't think in a different way.

 

[BON PLAN]

Yes he seemed very very well informed as he spoke about
300 + rafale deal in tranches along with mii component etc etc and it will be signed soon etc

But since nine of it came out true you are saying very " seemed..."

Past tense

not false !

 

[harsh]

http://www.indiandefensenews.in/2016/07/idn-take-tech-scan-brief-review-of.html?m=1

 

[BON PLAN]

http://www.indiandefensenews.in/2016/07/idn-take-tech-scan-brief-review-of.html?m=1

Very interesting ! really.

 

[Chinmoy]

The Kaveri is a variable-cycle, flat-rated engine and has 13% higher thrust than the GE F-404 engines equipping the LCA prototypes.

Variable cycle means airflow can be varied with temperature, altitude and fuel flow to maintain its thrust at a higher level all the time, a tech that is not in GE 404 or 414,

As far as I know, Kaveri is a high BPR engine in comparison to F404. This does give it the higher thrust while taking off, but at cruising altitude it gets beaten out by F404 in raw power.

Now variable cycle is something damn cool just like pulse jet or RAM/SCRAM hybrid engine, but did we worked enough on it to master it?

 

[shiphone]

Kaveri:..0.16-0.18
F-404: 0.34
RD-33：0.49

you have got all these engines within the nation, why enjoy empty talking all the time?
Kaveri's around 0.2 bypass ratio might be well known to me around two decades ago. it seem's R&D team didn't change the initial design...

and the funny statement on this forum that F404 is "far superior" in fuel consumption rate than RD33/93 is another interesting but baseless thing which I hoped some indian member could try to argue some day...but I didn't see it happened ...

 

[AnantS]

What are you trying to prove by those numbers o-chick-commie-10-center? Do you know it is a low by pass turbofan by design?

 

[ersakthivel]

As far as I know, Kaveri is a high BPR engine in comparison to F404. This does give it the higher thrust while taking off, but at cruising altitude it gets beaten out by F404 in raw power.

Now variable cycle is something damn cool just like pulse jet or RAM/SCRAM hybrid engine, but did we worked enough on it to master it?

kaveri is a low by pass flat rated variable cycle engine, which is designed to give optimum power in varying climatic conditions, a generation ahead of GE-404 , whose thrust ratings look good on paper for ideal test conditions , but when it encounters punishing summer climate(thats when wars most likely to happen in india , not in monsoons) its performance will fall far short of projected.

Thats why even a finished , bit below par kaveri will be better than GE 404 in real war conditions of varying altitude, humidity & temp, Trouble is it needs finishing the niggling issues, thats where the Snecma offer comes in handy.

 

[ersakthivel]

Kaveri:..0.16-0.18
F-404: 0.34
RD-33：0.49

you have got all these engines within the nation, why enjoy empty talking all the time?
Kaveri's around 0.2 bypass ratio might be well known to me around two decades ago. it seem's R&D team didn't change the initial design...

and the funny statement on this forum that F404 is "far superior" in fuel consumption rate than RD33/93 is another interesting but baseless thing which I hoped some indian member could try to argue some day...but I didn't see it happened ...

Lets start a discussion on low bypass ratio ,

http://aviation.stackexchange.com/q...itary-turbofan-engines-use-a-low-bypass-ratio

I know that the most civilian engines use a high bypass ratio which is good for fuel economy and noise reduction.

What prevents military engines from using the same technology instead of opting for low bypass engines?

Answers,

Because the priorities for military aircraft (engines) are different. While it is true that the high bypass turbofans have better fuel economy (in cruise) and are less noisy, the low bypass engines offer significant advantages when we take into account their intended use in combat aircraft, such as:

• The response of the low bypass turbofans to throttle adjustments is faster compared to the high bypass turbofans; the inertia is less and less air mass is involved (for increasing the velocity)- This is important during combat, when thrust requirements change rapidly.
• 
  
• [So tejas which was visualized to be at the cutting edge of the 90s 4.5th gen era needed an engine that changes thrust rapidly for its Relaxed Static Stability, low wing loading cranked delta design, for faster instantaneous turn oriented high ITR (Instantaneous Turn Rate)fight with high off bore Beyond visual range missiles for first shoot & kill advantage]
  
  
• They have less frontal area, reducing the drag produced. For aircraft expected to fly at supersonic speeds, however briefly, this is important.
• [Being the smallest fighter aircraft that is supposed to fit within the foot print of mig-21 low bypass low frontal area engine is an obvious choice for the low frontal area , low RCS airframe of tejas]
  
  
• Better thrust to weight ratio- 6:1 in Trent 1000 Vs 9:1 F119 (used in F-22 Raptor)- Even if the actual thrust produced by the low bypass turbofans is lesser, they produce more thrust per kg of engine, which means that the engine can be more compact in size.
• [Once again, Tejas being the low weight fighter the better TWR of low bypass engine will make it far more nimble]
  
  
• The low bypass turbofans are more efficient at higher speeds compared to the high bypass turbofans.
• [The RSS delta design of high speed high altitude combat that is the bread butter of IAF in high Himalayan kashmir or tibet area , fits perfectly with the Tejas requirement]
  
  
• The lesser size of the low-bypass turbofans mean that the aircraft can be made stealthier by 'burying' the engines in the fuselage, which is all but impossible in case of high bypass turbofans.
• {once again tejas was envisoned to be low RCS fighter, which also fits in with the low bypass engine spec]

It's not military vs civilian, but subsonic vs supersonic-capable
Note that subsonic military aircraft use the same engines as civilian aircraft, even if their names might be different.

• The KC-135 used initially the J-57 which was called JT-3C when used in the Boeing 707-120. Now they fly the CFM-56, which is used on the Boeing 737 and the A320.
• The C-5 Galaxy uses the GE TF39 which became the CF6 when mounted to a Boeing 747-100 or a DC-10.
• The Fairchild A-10 uses the GE TF34 which is called CF34 when mounted to civilian aircraft like the Bombardier Challenger.

No, the differences arise only when the aircraft is designed to fly supersonic. This requires a very different approach to the integration of the engine:

• Supersonic aircraft engines are mounted close to the centerline. If possible, they are straight behind the intakes, so the intake flow does not need to change direction. Exceptions like the SR-71 are rare.
• Supersonic intakes are longer and have sharp edges as opposed to the short, blunt intakes of subsonic aircraft. Also, most have a variable geometry to adapt to the very different flow conditions at supersonic speed.
• Since it is the job of an intake to slow down the air going into the engine, supersonic intakes cannot have a big capture area, or their spill drag in supersonic flight would be excessive. Supersonic engines need to create their thrust with much less airmass than purely subsonic engines. Forget stealth, this is the real reason for the smaller diameters of supersonic-capable engines.
• The nozzle of a supersonic aircraft is also variable, in contrast to the fixed nozzle of subsonic aircraft. This again helps to adjust it to the flow conditions, but in this case the major difference is between reheat on and off. Afterburning engines are capable of much higher exit speeds to compensate for their smaller diameter. They accelerate less air to a higher speed to create comparable thrust.
• The last point mentioned it, but it deserves a bullet of its own: Supersonic engines use afterburners in order to have enough thrust for going supersonic at all. The hot exhaust gasses have a much bigger volume than the cold intake flow which needs to be accommodated by widening the nozzle.

Note that the civilian Concorde used also a variable intake and nozzle and afterburners. It had an engine which was used on the BAC TSR-2 before, a supersonic military aircraft.

The real distinction is not between civilian and military, but between purely subsonic and supersonic-capable. Initially, both was achieved with the same engines. The J-57 mentioned above was also used on the supersonic F-100 military jet. Only in the 1960s did those lines diverge, and the subsonic aircraft grew ever bigger low-pressure compressor stages. These were again driven by the high-pressure cores which were used on supersonic aircraft.

Background
Thrust is air mass flow multiplied by the speed difference between flight and nozzle speed of the engine. To increase thrust, subsonic engines try to maximize mass flow (by increasing the bypass ratio) while supersonic engines rely more on increasing the nozzle speed (by using afterburners). Since net thrust is only possible when exit speeds are higher than the flight speed, the engine's exit speed needs to increase with the design flight speed.

The core engines do not differ much - after all, the intake will make sure that air reaches the engine at a speed of Mach 0.4 to 0.5, regardless of flight speed. The core of the General Electric F110 (installed in the F-15 and F-16 fighters, among others) became the core of the CFM-56 turbofan which is used in the Boeing 737 or the Airbus A320. The main difference is in their bypass ratio. The slower the design speed, the bigger the bypass ratio may become. At very low speed, the ungeared, shrouded fan is exchanged for a geared, free spinning propeller, in other words, the jet changes to a turboprop. The intake and nozzle, however, are very different indeed.

The optimum bypass ratio changes continuously, but since the drag coefficient drops after crossing Mach 1, airplanes are either designed for a maximum Mach number of 0.9 or less, or 1.6 and above. The corresponding bypass ratios today are up to 12 for subsonic engines, and less than 1 for supersonic engines. This produces a sharp boundary at the speed of sound, and many military engines designed for supersonic flight lost their afterburners and were fitted with a big fan to become the engines for subsonic transport aircraft.

The differences between sub- and supersonic engines grow bigger the more you move away from their core. High-pressure compressor, combustion chamber and high pressure turbine look and work the same, but the low pressure compressor of subsonic engines swallows a lot more air and has a much bigger diameter. Supersonic engines in turn mostly have an afterburner. The biggest difference, however, are the intakes (large pitot intake with blunt lips for subsonic aircraft versus adjustable spike or ramp intakes for supersonic flight) and the nozzle (fixed for subsonic flight versus a complex,adjustable convergent-divergent nozzle for supersonic flight). This is due to the very different air speeds and the much higher exit velocities required for supersonic flight.

Look at the intake section of the XB-70 pictured above (source). The capture area is rather small, and then the intake tube widens to enable the slowing of the airflow. The inclined sidewalls of the intake section cause a lot of drag at Mach 3. Now think the six GE YJ-93s are replaced by engines with an even bigger diameter. The increase in wave drag due to the even blunter intake would cancel out all advantages of a higher bypass ratio.

What is less obvious is the fact that this intake section also creates maybe half of the overall thrust of the propulsion system. But this answer is already too long, so I save this for another answer.

So that is why a finished kaveri is so integral to the india's AMCA effort as well,

Just looking at the plain thrust , SFC at optimum flight conditions makes low bypass engine a poor coice, but when you look at the fine print you can see lot of clarity on the low by pass requirement of tejas,

I have also read in BR(from maitya's post) that low bypass engine design allows one to reach the designated thrust with lower TET(turbine Entry Temp)

So given india's lower Metallurgy skills the low bypass design allows GTRE to achieve optimum thrust with lower TET capable engine blade Metallurgy, which is also a crucial need of tejas program,

So all this higher engine thrust to weight ratio per KG, low frontal area, achieving the needed thrust with lower TET turbine blades, of low bypass engine design is the back bone of engine tech for any super cruise 5th gen stealth fighter design that is the holy grail of fighter design today,

it is not for nothing that a true IIT , that too Metallurgy guy like Manohar Parrikar smells the potential of this low bypass variable cycle engine tech advantage & now in the thick of hard nose negotiations with Dassault raflae in exchange for finishing kaveri,

In my opinion if the GTRE-Snecma JV finish kaveri in 18 months with an uprated thrust of 95 KN , then the 36 rafales almost come free for IAF,

because this 95 Kn engine is a readymade fallback engine choice for AMCA as well, in case three are any delays in its engine program.

But I doubt whether it will become reality, because so many stones are killed by this one stone& it threatens too many western established interests as well!!

But it is a perfect fit for ADA & Dassault because as of now Dasault has no single engine fighter to sell unlike LM & Gripen,

Also if the 95 Kn thrust is achieved it gives them an uprated engine tech for the rafale upgrade as well.

No wonder Modi- Parrikar duo called off the scam ridden MMRCA circus floated by bribe seeking UPA regime & indulging in hard nosed top secret Govt to Govt negotiations on this rafale cum GTRE-Snecma deal.

Looking forward to your informed reply!!


Thanks