Kaveri Engine

airtel

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Bhai but
A 170Kn engine with afterburner will also make higher dry thrust than less powerful 140kn thrust engine like AL-41 which makes 86Kn of dry thrust.
Chinese 5Th generation fighter is a disaster because that jet cannot do super cruise and to make it capable of super cruise they aim to make WS-15 dry thrust 125KN and wet thrust 180KN.

J20 can not supercruise because it is less aerodynamic.
With the same engines su35 can easily supercruise.
There are ways to achieve desired speed other than installing big engines .
 

Concard

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110 kn dry thrust means about 180kn wet thrust and for a twin engine aircraft total thrust would be 360 KN ......Bhai TANK udana hai Kya ?😆😆
You know the reason I wish we have powerful engines is that in future if we want to equip AMCA with Bramhmos missile. And that's assuming internal bays are big enough to accommodate or Brahmos would undergo miniaturization to fit into AMCA without compromising range and speed. We paid somewhere around $3.5 billion for upgrades of 50 Mirage 2000 jets. The upgrade itself costed us more than the original price of the aircraft.

I understand the point @IndianHawk made with difficult to maintain and being expensive to operate. But we definitely need a heavier fighter which can strike deep into Pakistan and China. If we have a stealth aircraft which is capable of bringing death right at the enemy doorstep, that gives as a psychological edge. For now it's okay we don't have the resources and if AMCA is successful I hope in future we don't go for light aircraft or medium aircraft, we should go for the kill.
 

Assassin 2.0

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You know the reason I wish we have powerful engines is that in future if we want to equip AMCA with Bramhmos missile. And that's assuming internal bays are big enough to accommodate or Brahmos would undergo miniaturization to fit into AMCA without compromising range and speed. We paid somewhere around $3.5 billion for upgrades of 50 Mirage 2000 jets. The upgrade itself costed us more than the original price of the aircraft.

I understand the point @IndianHawk made with difficult to maintain and being expensive to operate. But we definitely need a heavier fighter which can strike deep into Pakistan and China. If we have a stealth aircraft which is capable of bringing death right at the enemy doorstep, that gives as a psychological edge. For now it's okay we don't have the resources and if AMCA is successful I hope in future we don't go for light aircraft or medium aircraft, we should go for the kill.
India can't make 160+Kn engine and can't get that technology if we make a heavy weight 5Th gen fighter we would also end up like Chinese with underpowered aircraft. It's better to build a perfect medium weight fighter with class leading engine.

Amca will not strike alone we will have different aircrafts which can carry big missiles like Su-30mki and tejas Mk2 amca will assist them.
US also uses F-35 with the package of Fa-18 in middle east.
 

Bhumihar

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110 kn dry thrust means about 180kn wet thrust and for a twin engine aircraft total thrust would be 360 KN ......Bhai TANK udana hai Kya ?😆😆
I think he was explicitly making a point for AMCA platforms.
F 22 has a dry thrust of 116kn and wet thrust of 160 kn
AMCA is lighter versions of F 22 but if we ever go for AMCA mk 2 we will need more thrust.
Also more thrust never hurts.
 

Concard

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India can't make 160+Kn engine and can't get that technology if we make a heavy weight 5Th gen fighter we would also end up like Chinese with underpowered aircraft. It's better to build a perfect medium weight fighter with class leading engine.

Amca will not strike alone we will have different aircrafts which can carry big missiles like Su-30mki and tejas Mk2 amca will assist them.
US also uses F-35 with the package of Fa-18 in middle east.
It's okay not now. But in 2040 we better have the technology and capability to build something like F-22 or F-35. Fingers crossed since this depends a lot on how big our economy is and our defense sector being vibrant with private sector participation. Technologically we should have progresses a lot by 2040.
 

Suhaan

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India can't make 160+Kn engine and can't get that technology if we make a heavy weight 5Th gen fighter we would also end up like Chinese with underpowered aircraft. It's better to build a perfect medium weight fighter with class leading engine.

Amca will not strike alone we will have different aircrafts which can carry big missiles like Su-30mki and tejas Mk2 amca will assist them.
US also uses F-35 with the package of Fa-18 in middle east.
But after getting access to know how about the core ,we will eventually make a bigger power plant for our other heavy aircrafts based on AMCA, that's the whole point about owning IPR,this is the first step i heard it will be a whole new core ,more powerful than Eurojet
 

IndianHawk

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It's okay not now. But in 2040 we better have the technology and capability to build something like F-22 or F-35. Fingers crossed since this depends a lot on how big our economy is and our defense sector being vibrant with private sector participation. Technologically we should have progresses a lot by 2040.
AMCA itself will more than match f35 level of stealth with much better aerodynamics. It's avionics will also be ahead of f35 ( which is actually 2000-2010 level technology. )

Barring indegenious engine we can easily match f35 level tech in next 10 years.

But USA will move a step ahead with next gen jet in next 10-15 years.
 

airtel

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If you mean 5th gen fighter engines then both XF9 and F119 are about 5 metres in length whereas F414 and EJ200 are about 4m in length.

It is easier to make a 5th generation Aircraft around a 4m engine as compare to a 5m engine .
Also consider it's diameter and serpentine air intakes .
A bigger engine would eat up the space for internal weapon bays ....this is why a compact engine with high thrust to weight ratio should be preferred .
USA and Japan are technically superior Nations and their engines are compact for the thrust they produce .....but then compare the dimensions of the Russian or Chinese engines , why J20's internal weapon bay's weapon carrying capabilities are so low despite bigger size of J20 ?🤔
 

IndianHawk

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If you mean 5th gen fighter engines then both XF9 and F119 are about 5 metres in length whereas F414 and EJ200 are about 4m in length.
F119 and XF9 are both for big heavy jets like F22 or su57 class.

We have yet to see what weight class European future jets FCAS and tempest came upto. Logic says they will be in F35 weight class since they need to be exported and hence costs need to be controlled.

So engine for these should be f414 size or slightly bigger .
 

ARVION

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F119 and XF9 are both for big heavy jets like F22 or su57 class.

We have yet to see what weight class European future jets FCAS and tempest came upto. Logic says they will be in F35 weight class since they need to be exported and hence costs need to be controlled.

So engine for these should be f414 size or slightly bigger .
XF 9's is a monster the final engine's will have a dry thrust of 140 KN's and a Wet thrust's of 200 KN's. It will weight around 2,000 Kg's and 4.8 m in lenght's and 1 m in Diameter's. The XF9-1 is a twin-spool axial-flow afterburning turbofan with a dual redundant FADEC, consisting of a 3-stage fan, a 6-stage high-pressure compressor, an annular type combustor, a single-stage high-pressure turbine, a single-stage low-pressure turbine, an afterburner, and a convergent-divergent nozzle.
 
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aerokan

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It is easier to make a 5th generation Aircraft around a 4m engine as compare to a 5m engine .
Also consider it's diameter and serpentine air intakes .
A bigger engine would eat up the space for internal weapon bays ....this is why a compact engine with high thrust to weight ratio should be preferred .
USA and Japan are technically superior Nations and their engines are compact for the thrust they produce .....but then compare the dimensions of the Russian or Chinese engines , why J20's internal weapon bay's weapon carrying capabilities are so low despite bigger size of J20 ?🤔
Let's look at it from a 'stealth/range to cover' perspective.

US has no near home enemies to fight. They have bases near all their far off enemies economic centers. So priority of stealth/internal payload over others.
Japan has the economic centers of their enemies within shorter ranges. So stealth over range.
China/Russia has vast swathes of land to cover while surrounded by possible enemy in all directions. So range to cover is premium over simple stealth. So bigger dual engine jets are preferred. China is making up their shortfall of range/stealth requirements by pouring more money in numbers.

Unfortunately India is on the similar boat as China. Although we have little less area to cover and have a sleeker profile, we have one small pest on the west for which stealth is more preferable(AMCA) while the economic centers of the eastern bats are far off where range is important (SU57ish). Bigger size engines for longer ranges explains the J20 and SU57 even without considering technical efficiencies of their respective countries.




 

airtel

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I think he was explicitly making a point for AMCA platforms.
F 22 has a dry thrust of 116kn and wet thrust of 160 kn
AMCA is lighter versions of F 22 but if we ever go for AMCA mk 2 we will need more thrust.
Also more thrust never hurts.
There are advantages of bigger engines and bigger aircrafts but there are disadvantages too .

To achieve more thrust bigger air intakes would be required ...and stealth fighters use serpentine air intakes so a lot of internal space would be used just to provide appropriate air to the engines that would reduce the space for weapon bays and make it difficult to design such a Aircraft .

To handle high thrust a stronger airframe would be required that means use of heavier materials instead of composites used by India .

Bigger engines would consume more fuel that means aircrafts would be forced to carry a lot of internal fuel which would again increase the weight of the aircraft and thus reduce the performance despite having bigger engines or their range would be reduced .

Bigger engines would consume more fuel per hour thus operational cost of such aircrafts would be extremely high and it would be difficult for countries like India to operate such costly aircrafts in large numbers .

There are many other reasons too .

This is why India is developing medium weight fighter jets .


There are advantages of bigger aircrafts too but As of now we don't have ability like Japan or USA to develop bigger engines .
It is better to make a useful aircraft than white elephants like J20 .
 

BangaliBabu

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USA and Japan are technically superior Nations and their engines are compact for the thrust they produce .....but then compare the dimensions of the Russian or Chinese engines , why J20's internal weapon bay's weapon carrying capabilities are so low despite bigger size of J20 ?🤔
Because communist propaganda is far more effective than ANY missile until, of course, shit hits the fan.
 

MonaLazy

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It is easier to make a 5th generation Aircraft around a 4m engine as compare to a 5m engine
Stealth heavies
F-22's F119 T/W 6.7:1 (dry), 9.0:1 (afterburning)
J20B is going into full rate production with AL-31 (about 5m in length) T/W 5.49 (dry), 8.75 with afterburner, 9.04 with emergency thrust
It's future engine the WS-15 T/W 9.7-10.87

Stealth Medium Weighters
F-35's F135 T/W 7.47:1 military thrust, 11.47:1 augmented
.. all the above are 5m engines

4m engines below..
FC-31 RD-93 T/W 4.82 (dry), 7.9 (afterburning)
it's future engine the WS-13 T/W = >8.5
EJ200 T/W 6.11:1 and 9.17:1 (with afterburner)
GE F414 58kN/98kN T/W 9

(*) all figures from wikipedia

As can be seen there is no disadvantage in T/W if opting for 5m engines, both can do a ratio of about 9 with AB. If the bigger engine eats up 1m in length then it also allows a 3m larger plane (F-22 19m, J-20 20m) vs medium weight stealth (F-35 16m, FC-31 17m). You stand to gain 2m in length for fuel and internal weapons with increased endurance.

AMCA is projected to be 17m long. From a stealth point of view it is better to have a single engine of like the F135 even if it eats up 1m because twin engines force a wider fuselage and throws stealth out of the window. You have to work harder to hide yourself- because you have more surface area and there is more maintenance cost by way of expensive RAM coatings that need to be touched up after every sortie.
 
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ARVION

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Stealth heavies
F-22's F119 T/W 6.7:1 (dry), 9.0:1 (afterburning)
J20B is going into full rate production with AL-31 (about 5m in length) T/W 5.49 (dry), 8.75 with afterburner, 9.04 with emergency thrust
It's future engine the WS-15 T/W 9.7-10.87

Stealth Medium Weighters
F-35's F135 iT/W 7.47:1 military thrust, 11.47:1 augmented
.. all the above are 5m engines

4m engines below..
FC-31 RD-93 T/W 4.82 (dry), 7.9 (afterburning)
it's future engine the WS-13 T/W = >8.5
EJ200 T/W 6.11:1 and 9.17:1 (with afterburner)
GE F414 58kN/98kN T/W 9

(*) all figures from wikipedia

As can be seen there is no disadvantage in T/W if opting for 5m engines, both can do a ratio of about 9 with AB. If the bigger engine eats up 1m in length then it also allows a 3m larger plane (F-22 19m, J-20 20m) vs medium weight stealth (F-35 16m, FC-31 17m). You stand to gain 2m in length for fuel and internal weapons with increased endurance.
It will take at least 5 year's to get the WS 15's engine at the J 20's.
 

airtel

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Stealth heavies
F-22's F119 T/W 6.7:1 (dry), 9.0:1 (afterburning)
J20B is going into full rate production with AL-31 (about 5m in length) T/W 5.49 (dry), 8.75 with afterburner, 9.04 with emergency thrust
It's future engine the WS-15 T/W 9.7-10.87

Stealth Medium Weighters
F-35's F135 T/W 7.47:1 military thrust, 11.47:1 augmented
.. all the above are 5m engines

4m engines below..
FC-31 RD-93 T/W 4.82 (dry), 7.9 (afterburning)
it's future engine the WS-13 T/W = >8.5
EJ200 T/W 6.11:1 and 9.17:1 (with afterburner)
GE F414 58kN/98kN T/W 9

(*) all figures from wikipedia

As can be seen there is no disadvantage in T/W if opting for 5m engines, both can do a ratio of about 9 with AB. If the bigger engine eats up 1m in length then it also allows a 3m larger plane (F-22 19m, J-20 20m) vs medium weight stealth (F-35 16m, FC-31 17m). You stand to gain 2m in length for fuel and internal weapons with increased endurance.

You didn't calculate the diameter and fuel consumption / hour into your calculations .
You didn't consider the effect of bigger diameter on air intakes and internal weapon bays .


What is the benefit of extra length of the aircraft if it's weapon carrying capabilities and range are not increasing in that proportion ?

American engines are extremely compact and efficient for the thrust they produce but Chinese and Russian engines are not .
 
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