LCA News and Discussions

nikhil_p · Post by **nikhil_p** » 19 Aug 2011 00:17

Paanwala update just in. Paanwala overheard the chaiwallah saying that LSP 7 almost ready and low speed taxi trial done. But they might not do first flight till the monsoon does not recede. Flight schedule has reduced because of low cloud cover over most areas making visual chase difficult.

Also paanwallah was saying that he is increasing cost of pan from 6 to 7.50. Also, pan has new addition of 120 supari.

ramana · Post by **ramana** » 19 Aug 2011 02:09

suryag · Post by **suryag** » 19 Aug 2011 02:48

What is 120 supari ?

SaiK · Post by **SaiK** » 19 Aug 2011 03:55

meaning, lower potency of the tamaku (zarda). so 120 is slightly less chaiwalaish than a 420!

hope I am right on the potency.. and it not a reverse order on AoA!

Singha · Post by **Singha** » 19 Aug 2011 06:16

6 to 7.5 refers to some pressure ratio in kaveri?
I would guess the 120 zarda is the kaveri2==tungabhadra of 120kn.

suryag · Post by **suryag** » 19 Aug 2011 06:38

ohh i thought 6->7.5 was G limits, great decoding sirjee i never would understand how you associated the pan thing to kaveri

Vivek K · Post by **Vivek K** » 19 Aug 2011 08:04

120 supari = GE404IN120; 6 to 7.5 means airframe certified for 7.5gs!

uddu · Post by **uddu** » 19 Aug 2011 08:39

About the engine, it's not clear. Kaveri being further developed to have 120KN thrust?
And one question is why not have Kaveri now on the first 40 Tejas? Is it similar to the US engine in terms of performance?

SaiK · Post by **SaiK** » 19 Aug 2011 08:51

let us get that 100kN first.

Sriman · Post by **Sriman** » 19 Aug 2011 09:00

Singha wrote:6 to 7.5 refers to some pressure ratio in kaveri?
I would guess the 120 zarda is the kaveri2==tungabhadra of 120kn.

Unit cost of 414 IN is $6m i think*. So $7.5m for a 120kn EPE engine?

*$600m for 99 engines?

SaiK · Post by **SaiK** » 19 Aug 2011 09:05

somebody needs to prove that 120kN on GE 414 exists?

then we can super cruise on lca.

Singha · Post by **Singha** » 19 Aug 2011 09:07

it does not - as yet. its the future EPE version which might touch those levels or something close.

kaveri in current form factor with Snecma help might get to 90 or even 95KN , but 120KN is a different ballgame and it will be quite different.

if such a project is taken up, we can call it tungabhadra (cradle river of vijaynagar) or malprabha(cradle river of chalukyas)

Thomas Kolarek · Post by **Thomas Kolarek** » 19 Aug 2011 09:13

For AMCA, we should have 156kN thrust in Kaveri similar to what Raptor F119 provides.

suryag · Post by **suryag** » 19 Aug 2011 09:16

Our chai wala has really confused us

SaiK · Post by **SaiK** » 19 Aug 2011 09:35

we can't be drinking porridge and seek to ride on ivory chariot. it is a long way to go!, but we have made the right step, and we need more budgeting on kaveri up-rated versions.

Rahul M · Post by **Rahul M** » 19 Aug 2011 11:09

Thomas Kolarek wrote:For AMCA, we should have 156kN thrust in Kaveri similar to what Raptor F119 provides.

how about a 1500 hp engine for the maruti 800 while we are at it ?

Singha · Post by **Singha** » 19 Aug 2011 11:24

the AMCA as shown will be smaller than raptor by few tons and will not need such platinum bullet thrust levels.
2 x 125kN should imo be more than enough - which is good, because the 414-EPE engine and EJ220 would reach those levels and be available for sale should kaveri-snecma never make it or get delayed.
also being a strike oriented bird, it would not need kimono shiver levels of t:w....VLO, passive sensors, precision long range weapons is more important

a giant Turuk bird known as Pakfa will be flying fast and high, to clear the way...

Rahul M · Post by **Rahul M** » 19 Aug 2011 11:50

few tons ? it would be ~ 50% of raptor's weight.

shiv · Post by **shiv** » 19 Aug 2011 13:49

Singha wrote:the AMCA as shown will be smaller than raptor by few tons and will not need such platinum bullet thrust levels.

er - pliss excyooz me onlee. I am tempted to say

shut up you naansense boy. What you know about this? If F119 engine power not there, then AMCA useless. Onlee

SaiK · Post by **SaiK** » 19 Aug 2011 17:03

^^but onlee J20 is allowed to take on Raptor naansense boy any day!!.. not fair!

/OT.

For Tejas Mk2, we have already signed up for 414, the near 100kN engine. These first is onlee expected to come by 2014 time frame. Perhaps koraput may get manufacture it only by 2015.

Kaveri could also get the same time frame to match up.. so, highly likely that we may look at subsequent LCA Mk2 with Kaveri 100kN.

Suresh_Shyam · Post by **Suresh_Shyam** » 19 Aug 2011 20:43

Thomas Kolarek wrote:For AMCA, we should have 156kN thrust in Kaveri similar to what Raptor F119 provides.

AMCA will be 20-25 tons Aircraft. So it's good enough to fit 110-125 Kn class Engine. GTRE can achieve this mark near future by having Single crystal blade from Snecma,BLISK Technology, further improve blade design and weight reduction in Engine. but it's not easy task. F-22 Raptor is 30-35 tons Aircraft, so it's needs F119 and it's world best engine. GTRE can't develop this kind of engine now.

shiv · Post by **shiv** » 19 Aug 2011 21:18

Suresh_Shyam wrote:F119 and it's world best engine.

Could you please point me to the criteria that have been used to classify the F119 as the "world's best engine". I really want to know how this assertion is being made.

I can name several engines that would fit that description so what are the parameters being used here? Some engines have been given that label (best engine) after tens of millions of flight hours. How does the F-119 match up?

Is it thrust to weight ratio? Low emissions? Fuel efficiency? Maintenance free operation? High MTBF? Resistance to bird hits?

SaiK · Post by **SaiK** » 19 Aug 2011 21:33

can't we use specially designed CNG for the hot sections?

tupolev has successfully ran with liquid methane.. with great efficiency. could also reduce IR signature.

Yogi_G · Post by **Yogi_G** » 19 Aug 2011 21:38

== dint know which other thread to put this so putting it here since its in context, sorry for OT
The claims on the f-119 being the best engine reminded me of the R-79 which equipped the Yak-41. Its a mai baap engine with one variant touching 200 KN wet thrust with dimensions not varying that much from the F-119. remember this one goes a bit earlier than the f-119 but its a big big monster. Pity the world never got a chance to see much of yak-41's performance.

More info on this enginer --> http://www.leteckemotory.cz/motory/r-79/index.php?en

Suresh_Shyam · Post by **Suresh_Shyam** » 19 Aug 2011 21:45

shiv wrote:
Suresh_Shyam wrote:F119 and it's world best engine.
Could you please point me to the criteria that have been used to classify the F119 as the "world's best engine". I really want to know how this assertion is being made.

I can name several engines that would fit that description so what are the parameters being used here? Some engines have been given that label (best engine) after tens of millions of flight hours. How does the F-119 match up?

Is it thrust to weight ratio? Low emissions? Fuel efficiency? Maintenance free operation? High MTBF? Resistance to bird hits?

In term of thrust to weight ratio. Sorry, it's one of the best engine.

nikhil_p · Post by **nikhil_p** » 19 Aug 2011 21:45

120 = GE414 pahuch gaya hai...
and it is about G limits.

Sorry for the confusion, was away from the comp till now.

Singha Saar - Something to make the Jingo in you happy...the chaiwallah did mention that River engine is performing well, in Mk2, because of slighly higher available diameter we can reach 90-95KN. Tests ongoing.

SaiK · Post by **SaiK** » 19 Aug 2011 22:33

then the river needs to run on SC blades and blisks, with a new blade design and shapes to generate max thrust.. Innovate off the GE414, 120 wala as the baseline.

lets get gang-o about it. river 120 supari is the way to go. why cut our legs further to fit the shoe?

Drishyaman · Post by **Drishyaman** » 19 Aug 2011 23:41

nikhil_p wrote:the chaiwallah did mention that River engine is performing well, in Mk2,

hain !!?? Plan confirmed for river engine in MK2?

nikhil_p wrote:because of slighly higher available diameter we can reach 90-95KN. Tests ongoing.

if the diameter is increased to achieve 90-95 KN... won't that make MK2 fat ? guess frenchie.... single crystal blade and blisk... would be a better idea to keep the river engine slim and trim...?

nash · Post by **nash** » 20 Aug 2011 06:55

i think there is no increase of diameter , as now only it is bigger than the 414, Ej and m-88 , so may they are talking about increase in thrust with the current bigger diameter..

suryag · Post by **suryag** » 21 Aug 2011 07:00

nikhil_p ji any updates on the wake penetration tests, guided missile firing or radar integration with stores ? Eagerly waiting for the monsoon to recede to see lsp7/lsp8 and nlca in the air.

NRao · Post by **NRao** » 21 Aug 2011 17:02

if the diameter is increased to achieve 90-95 KN... won't that make MK2 fat ? guess frenchie.... single crystal blade and blisk... would be a better idea to keep the river engine slim and trim...?

i think there is no increase of diameter

He said "slighly higher available diameter ", which should mean that there is some play there. So, where does this thinking of increasing it come in?

Drishyaman · Post by **Drishyaman** » 21 Aug 2011 17:51

NRao wrote:He said "slighly higher available diameter ", which should mean that there is some play there. So, where does this thinking of increasing it come in?

Sir !! Please define "slightly higher available diameter ". Is it 1 inch ? 2 inch? 5 inch? 10 inch?

And how much play is available ? And why is the play made available currently in MK1 ? Why can the play be done away with in MK2 i.e. why the play won't be necessary in MK2 ? Could you please, explain in details.

SaiK · Post by **SaiK** » 21 Aug 2011 17:58

For Mk2, the project charter allows for frame redesign.. where as for Mk1, there is no such requirements in the schedule. So, Mk2 has been given the time to resize both the engine and the airframe, depending on the requirements. [the "redesign": meaning slight improvements to accommodate for the approved upgrades for FoC].

NRao · Post by **NRao** » 21 Aug 2011 17:59

Why do you want to create a problem when there is none? He said, clearly, that there is available diameter to perhaps achieve the 90-95 Kn. It could be a few mm or a few cms. It does not matter. The fact remains that the MKII will not get fatter.

nikhil_p · Post by **nikhil_p** » 21 Aug 2011 18:23

suryag wrote:nikhil_p ji any updates on the wake penetration tests, guided missile firing or radar integration with stores ? Eagerly waiting for the monsoon to recede to see lsp7/lsp8 and nlca in the air.

Nothing at this point of time. I will update when paanwallah comes to chaiwallah.

Drishyaman wrote:
NRao wrote:He said "slighly higher available diameter ", which should mean that there is some play there. So, where does this thinking of increasing it come in?
Sir !! Please define "slightly higher available diameter ". Is it 1 inch ? 2 inch? 5 inch? 10 inch? And how much play is available ? And why is the play made available currently in MK1 ? Why can the play be done away with in MK2 i.e. why the play won't be necessary in MK2 ? Could you please, explain in details.

The slightly available diameter increase is exactly the square root of 3 multiplied by the 4th root of 2 divided by the 17th root of 1796.

Do a simple calculation if a circle of say X diameter (X is cms) is increased by 'x' (x is mm) what will the increase in volumetric flow be keeping everything else constant. You will see what a simple increase in 8-10 mm can make a difference.

Also, if you do not know the meaning of paanwallah/ chaiwallah information suggest you read the BR wiki.

Play is not 'made' available. It is always built into the airframe to ensure space for other allied stuff (cables etc). If you reduce the thickness of the structural rib by a couple of mm (5 mm) with a change in the strength of material (better alloys for example) an increase in space can be achieved.

SaiK wrote:For Mk2, the project charter allows for frame redesign.. where as for Mk1, there is no such requirements in the schedule. So, Mk2 has been given the time to resize both the engine and the airframe, depending on the requirements. [the "redesign": meaning slight improvements to accommodate for the approved upgrades for FoC].

Perfect response sir.

nash wrote:i think there is no increase of diameter , as now only it is bigger than the 414, Ej and m-88 , so may they are talking about increase in thrust with the current bigger diameter..

Only one stage is larger. It is keeping in line with the diameter increase envisaged for the Mk2

Drishyaman · Post by **Drishyaman** » 21 Aug 2011 20:54

nikhil_p wrote:The slightly available diameter increase is exactly the square root of 3 multiplied by the 4th root of 2 divided by the 17th root of 1796.

Do a simple calculation if a circle of say X diameter (X is cms) is increased by 'x' (x is mm) what will the increase in volumetric flow be keeping everything else constant. You will see what a simple increase in 8-10 mm can make a difference.

I am impressed with your formula

Good work !!

nikhil_p wrote:Also, if you do not know the meaning of paanwallah/ chaiwallah information suggest you read the BR wiki.

Play is not 'made' available. It is always built into the airframe to ensure space for other allied stuff (cables etc). If you reduce the thickness of the structural rib by a couple of mm (5 mm) with a change in the strength of material (better alloys for example) an increase in space can be achieved.

Couple of questions :
1. Your chaiwalla seems to suggest that there will be design changes to the air frame i.e. there would be reduction of the thickness of the structural rib, correct?
2. So, better material being used or better design being done, to keep the strength of the airframe constant, correct?
3 To accomodate a larger diameter engine some of the available play will be used i.e. space available for "allied stuff(cables etc)" will be used, then will that limited space affect affect maintenance or overhaulling of the engine ?
4. Will the increase in diameter of the engine, increase the weight of the engine, if that be the case then airframe structure has to increase which inturn will increase the weight of the aircraft, no?
5. If the increase in diameter doesn't increase the weight of the engine, then that would suggest better and lighter material usage i.e. may be scb or blisk or may be some lighter alloy, right?
6. Then, Won't it be a better idea to keep to keep the diameter constant but increase the thrust of the engine by some other way as suggested above because that would minimize rework on air frame. Already there talks floating that MK1 is fat and the fuselage has to be redesigned so as to reduce the drag ?

PratikDas · Post by **PratikDas** » 22 Aug 2011 01:03

Drishyaman, I think you're being unfair to a BR friend who is sharing something when he doesn't need to share anything at all. My personal opinion is that I don't care how India achieves the conflicting goals of both Thrust and T/W ratio if it means having an engine with a wider diameter. If not for the Mk1, or even the Mk2, then for the AMCA and for the decades to come. We need an Indian engine. SCBs, larger blisks (compressor, not just turbine) and all that good stuff can come later.

We need an operational Indian engine deployed in an operational aircraft. Then watch the international prices come crashing down.

SaiK · Post by **SaiK** » 22 Aug 2011 03:22

I think IAF is more interested in aerodynamic requirements and what it needs to deliver a weapons load with the required turn rates and AoA. They are least concerned now on the "light" version of LCA. If we wish to rename to "Large" for L, make it so!.

Yes, we would definitely like to have the light version in stages.. we need this puppy in squadrons, and blocks. If Migs can get upgraded, LCAs can be upgraded as well.

NRao · Post by **NRao** » 22 Aug 2011 03:27

Will have to wait for the test results. There seems to be enough of everything to perhaps achieve 90-95 KN.

No need to let speculation enter the equation at this time. Nothing has been said to let any speculation to enter either.

Sagar G · Post by **Sagar G** » 22 Aug 2011 11:50

Drishyaman wrote: Already there talks floating that MK1 is fat and the fuselage has to be redesigned so as to reduce the drag ?

Will you please point us to these "talks" ???