ADA Tejas (LCA) News and Discussions

[Enquirer]

Modern jet engines get,

Higher thrust from better SCB blades,

withstanding higher tubine entry temperature,

leading to higher thermodynamic efficiency, due to higher energized mass flow,

Produce the same thrust for lesser fuel,

& these engines come smaller & lighter especially.

Heavier weight, lower thermal efficiency, bigger size, fuel guzzling engines,

Increase both the radar,heat signatures of the fighter,

Along with higher fuel needs, leading to spiraling weight gain of the fighter.

They r the past, not future

Certainly not the future of jet propulsion.

Why are you stating the most obvious stuff??
But none of that is applicable to refute the specific point being discussed.

 

[Narasimh]

Air marshal Mateshwaran, who headed the, "rejection" committee, once opined

Why only 6 stages on kaveri,,,,,
increase it, to 10 or 12, it doesn't matter, all we need is more thrust.

He is oblivious to even the simple fact, that modern jet engines derive higher thrust,

by increasing thermodynamic efficiency, through higher TET,
& operating pressure,

there by reducing stages & engine weight,,

Because what matters I not just absolute thrust, but engine thrust to Weight ratio.

Kaveri is shorter than GE 404,


Such genius being given appointed to head the committee, to evaluate, snecma GTRE jv

has made IAF & GOI a laughing stock around the tech world,,,

Because Pratt & Whitney guys who hv experience In variable cycle engines inspected kaveri & said it is a world class engine,

even the French don't hv kaveri's variable cycle jet engine technology, the same tech which powers F22

That says a lot about the, "technical capabilities" of IAF review committee headed by Air marshal, "Matheswaran".

Goto Bharathrakshak kaveri engine thread & read a few of, Maitya's post about what design changes will unleash the full potential of kaveri, before placing expert here.

Just because your old favorite forums went belly up, don't litter DFI with falsehoods.

In the Vayu Roundtable, it seems Air Marshal Matheswaran is countering his own previous stance regarding the Engine (watch : 2:39 to 5:11). Is that correct? :

 

[charlie]

Any tech development is based on requirements, but the US prefered to develop just a longer range AIM 120, while Europe understood that speed not range is the key and developed Meteor.
Same goes for WVR missiles, where Europe started developments of HOBS missiles as a reaction to R73 and because AIM 9 was inferior and when you see how many customers prefer European missiles over AIM 9X, you will understand where the know how is.

First why are you holding on to Air to Air missile, there are hundreds of things where US is much ahead of Europe that there is no point to debate.

It's not Europe understood that speed not range is the key, It's a different school of thought, you need to read those studies done for BVR to see american school of thought (2008) to understand why the budget for longrange was decreased in favour of other concepts. The AIM D model only lacks ramjet tech with variable fuel which will be covered in SSTRR but I don't think it will be ordered (by the way development is within 18 to 30 month). I assume you have no clue of DOD budget for the LREW which is going to be much better then anything in world that is currently deployed.
https://comptroller.defense.gov/Por...E/OSD_0400_PB_18_Justification_Book_Final.pdf

There were a lot of study like this - https://www.defenseindustrydaily.com/files/2008_RAND_Pacific_View_Air_Combat_Briefing.pdf
https://books.google.ca/books?id=NiolDwAAQBAJ&pg=PA269&lpg=PA269&dq=bvr+in+future+US&source=bl&ots=s5fIIAOOob&sig=QVFdmcOI1e12MxMb8q0mNv-uO-0&hl=en&sa=X&ved=2ahUKEwibm4KPprjcAhWzHjQIHePJAVkQ6AEwB3oECAcQAQ#v=onepage&q=bvr in future US&f=false
Most of the report concluded they need more close,secure airbases, better BVR( In sensor and maneuvering terms), smaller missile so more missile can be carried.

Back in 2008 I noticed one word used a lot it was "Low cost" it seems US understood very well that having a high end system will not win war. it's the low cost dispensable system which will be key to sustain war. I think the future of US will be divided between 80/20.

But US is being US so they will still go for LREW but for that all the segments needs to be engineered not just the missile.

This is a Tejas thread I don't want to discuss anything else. If you want you can create another thread and we will discuss over there.

 

[ersakthivel]

Why are you stating the most obvious stuff??
But none of that is applicable to refute the specific point being discussed.

Getting 20 percent more thrust by 20 percent increase in weigt.
Leads to more weights getting added everywhere.

Planes body gains more weight by the way of stiffeners to support this engine weight.


Thermodynamic inefficient needs more fuel for the same range,there by increasing fuel weight & tank's volume & weight.

Much worse all this weight increaase is at the tail, far away from CG, leading to more complications elsewhere.

Landing gear gains more weight.

Your plane's RCS, Heat signatures increase.

Remember all these weight additions can be justified only when plane is operating at peak thrust at take off , or supersonic missile launch.

Close combat is done at corner speeds, far below max thrust ,

So all these weight jut penalise the fighter at a dog fight,

Your plane's STR, ITR suffers, because all these specs are not performed at peak engine thrust or top engine energy level.

ITR, STR are vital specs at corner speeds, a speed far below top engine thrust & feed.

So excessive weight all over the plane , just because of older tech engine needing more stages to produce thrust spoils everything.

It is not as plain as ,"you idiot ,what's wrong with 3percent" weight increase."

 

[ersakthivel]

In the Vayu Roundtable, it seems Air Marshal Matheswaran is countering his own previous stance regarding the Engine (watch : 2:39 to 5:11). Is that correct? :

I can't get what is being said, becaus of video problem.
Post what's being said.

 

[Enquirer]

Getting 20 percent more thrust by 20 percent increase in weigt.
Leads to more weights getting added everywhere.

Planes body gains more weight by the way of stiffeners to support this engine weight.


Thermodynamic inefficient needs more fuel for the same range,there by increasing fuel weight & tank's volume & weight.

Much worse all this weight increaase is at the tail, far away from CG, leading to more complications elsewhere.

Landing gear gains more weight.

Your plane's RCS, Heat signatures increase.

Remember all these weight additions can be justified only when plane is operating at peak thrust at take off , or supersonic missile launch.

Close combat is done at corner speeds, far below max thrust ,

So all these weight jut penalise the fighter at a dog fight,

Your plane's STR, ITR suffers, because all these specs are not performed at peak engine thrust or top engine energy level.

ITR, STR are vital specs at corner speeds, a speed far below top engine thrust & feed.

So excessive weight all over the plane , just because of older tech engine needing more stages to produce thrust spoils everything.

It is not as plain as ,"you idiot ,what's wrong with 3percent" weight increase."

Once again you're throwing darts all over the place without making a cogent argument!
I didn't say anything about how the 20% additional thrust is gained from - you're just assuming that it would come from a thermodynamically inefficient mode that would guzzle gynormous amount of fuel!
What would be the harm if the 'hot engine' operation was made possible by materials that wasn't as weight efficient as SCB? It could use some new ceramics etc! And what if it needed some additional heat dissipation mechanism....
20% 'engine' weight doesn't have to result in 'dead' weight everywhere! CG balancing can be achieved by just having additional payload (made available via additional thrust) in the wing & aft regions.
Also, Fuel is mostly carried in the wings!
Landing gear will barely need any modifications (what with a mere 3% increase in empty weight!). Additional weight and stronger landing gear (if any) will only come from a deliberate expansion of the MTOW spec.
I won't respond any more to the illogicial argument. Thanks.

 

[ersakthivel]

I would highly recommend to you to read more and inform yourself, no matter where and from whom, because you have a clear lack of knowledge and understanding for sure. I don't need to go to other forums, since my aim is always to seek and "share" credible infos wherever I am =>


https://defenceforumindia.com/forum/threads/kaveri-engine.5097/page-119#post-1382731

IAF has committed close to 300 tejas in all versions,

& This Air Marshal Matheswaran wants LCA Program closed.!!!!

If such a guy heads a ,"committee" to scrutinize snecma-gtre jv,

What would be his recommendation??

Close that as well.

Later he was appointed to advice HAL as well.

Did he counsel HAL to clos the tejas line??

 

[Shashwat]

Sp10 flew-


30 chars...

 

[ersakthivel]

Once again you're throwing darts all over the place without making a cogent argument!
I didn't say anything about how the 20% additional thrust is gained from - you're just assuming that it would come from a thermodynamically inefficient mode that would guzzle gynormous amount of fuel!
What would be the harm if the 'hot engine' operation was made possible by materials that wasn't as weight efficient as SCB? It could use some new ceramics etc!
20% 'engine' weight doesn't have to result in 'dead' weight everywhere! CG balancing can be achieved by just having additional payload (made available via additional thrust) in the wing & aft regions.
Also, Fuel is mostly carried in the wings!
Landing gear will barely need any modifications (what with a mere 3% increase in empty weight!). Additional weight and stronger landing gear (if any) will only come from a deliberate expansion of the MTOW spec.
I won't respond any more to the illogicial argument. Thanks.

Fuel in the wings,

All fuel tanks in fuselage are filled with compressed air perhaps,


Weight efficiency of SCB Blades???

It is the metallurgical composition which governs TET sustainability ,

not weight.


It's better to close our conversation.

That's the only thing I agree in your post.

Let it be.

 

[ersakthivel]

Better hot section SCB Efficiency doesn't require additional stages that leads to engine weight gain.

That's what I meant in the first place.

 

[ersakthivel]

Sp10 flew-


30 chars...

If at all GOI heeded Air Marshal Matheswaran'' wise counsel in Vayu stratpost round table,

No tejas will fly in IAF colors.

Matheswaran & co will bankroll any foreign acquisition, which will be twice as costly as tejas by selling their family assets perhaps.

It was Providence that the scam central UPA lost & Manohar Parrikar kitted mk1A to revive tejas.

 

[WolfPack86]

Some where i heard 10th Tejas aircraft will join in one week with air force. But i am not sure about it.

 

[patriots]

Some where i heard 10th Tejas aircraft will join in one week with air force. But i am not sure about it.

today sp10 ..flew for first time.......
will join after few more flights....

 

[Prashant12]

#Tejas SP-10 completes maiden flight at #HAL airport. "Extremely smooth flight," says #HAL officials. Flight lasted for 35 min and was piloted by Gp Capt K K Venugpopal (Retd) of NFTC

 

[ersakthivel]

It's not that I don't understand, it's just that I disapprove of much of your mumbo-jumbo.
There's no point scoring, just keeping the record straight so other folks don't get sucked into your vortex of misinformation.
I read your postulations on Levcons, engines & general aerodynamics in your posts - they all reek of an authoritative amateur.
You've read up on aerodynamics without a strong foundation in physics - that's your fundamental issue.

What I said was ,

To increase thrust from 80 KN to 100 KN,

Say the engine weight is increased by 20 percent, I.e 150 kg, instead of increasing thermal efficiency by increasing TET,

It results in strengthening of airframe by X kg to support the extra engine weight,

Since engine sits at the tail, to compensate for CG We may need Y kg weight increase some where else.


To suport this 150 kg+X kg+Y kg landing gear needs to be strengthened by Z kg.

This 150+X+Y+Z kg reduces range & weapon load .


When plane is taking off with full afterburner thrust, due to 20 KN increased thrust,

this 150+X+Y+Z kg extra weight doesn't matter.


But in close combat , planes don't fly at top speeds & full after burner thrust of peak 100KN.

They fly at corner velocity , with far lower thrust than peak thrust of 100 KN.

At that time this 150+X+Y+Z kg will be a dead weight on the fighter,

Which results in lower AOA, ITR, STR,

A fighter with lesser weight, higher efficient engine will keep the edge in close combat with higher weight lower efficiency fighter.

So increasing engine weight ,

for higher peak thrust, without corresponding thermodynamic efficiency, is not advisable.

That's why rafale with far lesser powered engines Supercruise, while many older fighters with far higher powered engines can't.




What is so hard to understand??

What mumbo, jumbo you disapprove of ???

What amatuer postulations on levcons, aerodynamics, without physics base, blah, blah,

Don't write essays with your subjective opinions on me.

That's uncalled for. &Not meant for this thread as well.

 

[ersakthivel]

Dude,


Increasing one stage for higher thrust will lead to 100 +kgs In engine itself.

Add other X+Y+Z factors.


You may be looking at close to half a ton , with consequent increase in mtow.

Then landing gear has to be adjust ed.

1percent , 2 percent weight increase is no matter at all .

Dude! There you go once again flinging nonsense in all directions with the hope that something will stick!!!
Increasing the thrust by 20% (and all the technical discussions associated with it) revolve around DRY THRUST!
What good are SCBs for increasing the wet thrust????
These's a reason wet thrust involves AFTERBURNERS (there're no compression blades in the afterburner!!!!).
By definition SuperCruise involves ONLY dry thrust!!!
So, the material tech that's being sought/developed is to primarily to increase DRY THRUST. (It's just incidental that there happens to be implications for Wet thrust also)

You just MUDDLED everything (like a guy pretending to speak a language that he has no idea of but definitely gets the accent right!) by throwing terms left, right & center!!!

Also, nobody redesigns the landing gear because the all-up weight went up by around 1%!!
If they wish to requalify the aircraft for a higher MTOW (one of the advantages of higher thrust) then MAYBE (i.e. if MTOW also goes up by 20%!!!!!)

I wish you could analyze things completely before your post. You just fool/terrorize people into believing that you're a guru by throwing terms from aerodynamics that they may not have heard of before!!!

Strike out the word wet thrust & replace it with dry thrust of 100 KN.

Still all my arguments are true.

Who is fooling & terrorizing the thread with gunghho attitude?

All key fighting specs of fighters like AOA, ITR,STR are all attained at corner velocities, not at the peak dry thrust is my idea.

Because at higher thrusts speeds increase & agility suffers,


Fighters hv a specific design thrust or speed level to pull high Gs, AOAs, ITRs, STRs, is my opinion.

This thrust & speeds are not designed as peak dry thrust or wet thrust, or top speed

A heavier weight lesser efficiency engine affects these specs adversely .


So having a lighter weight higher efficiency engined fighter helps in increasing these specs & attain supercruise, without any other sacrifices is my opinion.

That's why I used rafale, as an analogy.

Rafale attains supercruise because of lighter weights & higher efficiency engine , giving high enough dry thrust for its weight.


Increasing the weight of SCBs too present same complications.

What is the engine rpm?
What is the centripetal force?
How much weight needed to strengthen the BLISK?


Only better metallurgical SCB Blades gives a competitive fighter.


All my arguments are about the pitfalls of going for a higher weight engine to obviate thrust shortfall.

 

[Enquirer]

Dude,


Increasing one stage for higher thrust will lead to 100 +kgs In engine itself.

Add other X+Y+Z factors.


You may be looking at close to half a ton , with consequent increase in mtow.

Then landing gear has to be adjust ed.

1percent , 2 percent weight increase is no matter at all .

100kg extra weight in one half of the plane will lead to 500kgs of support structures PLUS additional weight of the landing gear??? So you're saying 100kg of additional engine weight will result in 500-1000kg of extra weight?
Have you ingested some magic mushrooms?? &hallucinating?
Most likely you're a poor student of physics!!

Did did you know that Tejas is designed to carry nearly 2500 kg (fuel) internally and another 4000 kgs (weapons) externally. And you're saying that the SPINE of the aircraft cannot take 100kgs extra. LOL!!!

Strike out the word wet thrust & replace it with dry thrust of 100 KN.

Still all my arguments are true.

100 KN of dry thrust?? Are you kidding? Tejas will have supercruise capability with that!
Also, you didn't just make a typo of 'wet' vs 'dry'. You took pains to describe FULL AFTERBURNER THRUST multiple times and also called it PEAK THRUST! You can't wriggle out of your folly by a simple replacement of wet with dry!

Who is fooling & terrorizing the thread with gunghho attitude?

You!

All key fighting specs of fighters like AOA, ITR,STR are all attained at corner velocities, not at the peak dry thrust is my idea.

Because at higher thrusts speeds increase & agility suffers,


Fighters hv a specific design thrust or speed level to pull high Gs, AOAs, ITRs, STRs, is my opinion.

This thrust & speeds are not designed as peak dry thrust or wet thrust, or top speed

A heavier weight lesser efficiency engine affects these specs adversely .

Again a TONNE OF BS from you.
Turbofan thrust (even dry) can be throttled. Just because the engine has a high limit of dry thrust, it doesn't mean it cannot employ lower thrust when required!
What you're saying is like Usain Bolt cannot function in normal society because city streets require people to walk slowly!

So having a lighter weight higher efficiency engined fighter helps in increasing these specs & attain supercruise, without any other sacrifices is my opinion.

That's why I used rafale, as an analogy.

Rafale attains supercruise because of lighter weights & higher efficiency engine , giving high enough dry thrust for its weight.

No one is debating that a lower weight , smaller engine is good for an aircraft.
But I am calling BS on your assertion that even a slight increase in engine weight is disastrous to the aircraft!
As I have explained multiple times already a 20% increase in engine weight only results in 1% to 2% increase in the overall aircraft's weight (simply because the engine is only a small portion of the aircraft weight!). As such some inefficiencies can be tolerated!

 

[ersakthivel]

Not surprising at all that a dimwit like you would err so poorly on math & logic!!!
20% increase in engine weight means only around 3% increase in aircraft's empty weight and only around 1.5% increase in the fully-loaded weight!!
So, 20% increase in thrust for 1.5% to 3% increase in total weight!! Only a confirmed idiot like you will think that's a bad deal!!

20percent increase in engine weight comes close to 150 KGs, if we take 850 to 950 KGs as original engine and weight.

Apply the 150 KG + X+Y+Z , you will get the idea of total empty weight increase.

All this weights will penalise AOA, Gs pulled, ITR,STR at corner velocities,

which are far below high sub sonic speeds, (obtained at a thrust lower than peak dry thrust)


is the argument.

Yelling confirmed idiot,
Dimwit,
Mumbo jumbo,
Terrorizing the thread,
Mumbo jumbo.
Postulations on levcons & aerodynamics without understanding basic physics,

Blah, blah, blah,

is not going to enlighten any one, I suppose.

 

[ersakthivel]

Engine weight being uniformly distributed throughout the fuselage is news to me.

Are you talking about 7th fighters equipped with warp drives?

You seem like a guy who dies of an ant prick!
150 kgs extra weight right inside the spine of the aircraft & uniformly distributed DOESN'T NEED ANY ADDITIONAL STRENTHENING!
950 kgs of additional weight?? You're completely over reacting!
If you're even half sane you probably know already that you screwed up, but are arguing just for the sake of ego - like that dude Chinmoy (who still keeps entangling himself with thrust, weight, drag etc - someone should get him some simpler toys to play with).
If you really believe in all the nonsense you're writing, then I have profound sympathy for you!

N

 

[ersakthivel]

Dude! You definitely need some psychiatric help (not to mention help with basic physics!)
Who dragged this conversation into the mud by calling me 'idiot'?
Perhaps you suffer from short term memory loss....no wonder you remember nothing about physics or aerodynamics (if you ever read them that is).




I can tell that you didn't do well at an engineering school (if you went to one that is!). If you think you're a smart guy then you should go back to your engineering school and ask for refund - cause they didn't give you a value education; but I have feeling it's all you!



Please take you ignorance elsewhere. You've spread enough here to ruin some curious minds!
I tried my best to give you a free education, but your head is already filled with delusions of self-grandiose!

I am more than capable of doing without your free education.

I know the worth of the institution which gave me education & the worth of your advice regarding asking for refunds.



Enough from both of us.

Now lets call off this wasteful name calling & be done with it, since we both know, how we evaluate & respect each other.

Let other members judge who is right, who is wrong.

Lets disengage like adults with some semblance of civility..