LCA TEJAS MK1 & MK1A: News and Discussion

IndianHawk

Senior Member
Joined
Sep 24, 2016
Messages
9,058
Likes
37,670
Country flag
????? What you even mean by this???

We need a low bypass engine. Fighters all over world use low bypass engine.
I mean it's way too low for kaveri compared to ge404.
F404 has a bypass ratio of 0.34 while f414 has 0.25
M88 has 0.30
Compared to 0.16 for kaveri.

Back in 1980s ge404 was the most advanced engine for light / medium fighters in the world. So we tried to match the thrust of gef404 while compromising on fuel efficiency. ( As we couldn't match both )
A concept of leaky turbojet. Which is as good as a turbofan but not as advanced or fuel efficient as western contemporary turbofans .

See both f404 and m88 have almost double the bypass ratio of kaveri and both are most fuel efficient engines in their class.

At least this is my understanding . I could be wrong on this though so don't take it seriously.
 

Bleh

Laughing member
Senior Member
Joined
Nov 23, 2017
Messages
6,175
Likes
25,855
Country flag

Guys what are capabilities of plain tejas mk 1?.....not mk 1a mind you.
Read the wiki page. Meticulously inserted everything, every faeture & achievements in there.
Updated the images too... Today only.
 
Last edited:

Akula

Senior Member
Joined
Apr 24, 2019
Messages
2,895
Likes
10,850
Country flag
Read the wiki page. Meticulously inserted everything, every faeture & achievements in there.
Updated the images too... Today only.
Bleh please edit Indian army equipments page on Wiki. Someone has fu**ked up the page. Akash range has been changed to 100km.
 

Bleh

Laughing member
Senior Member
Joined
Nov 23, 2017
Messages
6,175
Likes
25,855
Country flag
One thing that genuinely confuses me about Tejas is its turning. How come the pilots keep doing turns upon turns, without any noticeable performance detrimention?.. I understood that deltas tend to lose energy faster.

Someone explain plz. There was a rant about F-16's STR few pages ago.

Bleh please edit Indian army equipments page on Wiki. Someone has fu**ked up the page. Akash range has been changed to 100km.
I'm not really aware of all the accurate data. @porky_kicker @Karthi. Little help?
 
Last edited:

vishnugupt

Senior Member
Joined
Dec 3, 2013
Messages
2,583
Likes
11,048
Country flag
Read the wiki page. Meticulously inserted everything, every faeture & achievements in there.
Updated the images too... Today only.
You are a Man of Passion, I was about to tell you to upload Exact pic of LA-5017 but you know exactly where is LCA's heart lies. You know even the pulse of LCA fans. People like you are the reason that Tejas has survived all odds and ready to smash neighbouring borders. Best regards
 

porky_kicker

Senior Member
Joined
Apr 8, 2016
Messages
6,024
Likes
44,579
Country flag
One thing that genuinely confuses me about Tejas is its turning. How come the pilots keep doing turns upon turns, without any noticeable performance detrimention?.. I understood that deltas tend to lose energy faster.

Someone explain plz. There was a rant about F-16's STR few pages ago.


I'm not really aware of all the accurate data. @porky_kicker @Karthi. Little help?
Upto 35 km

Different sources mention different ranges from 25 - 35 km

I will take the upper limit of 35 km
 

Karthi

Senior Member
Joined
Jul 15, 2018
Messages
2,214
Likes
17,753
Country flag
One thing that genuinely confuses me about Tejas is its turning. How come the pilots keep doing turns upon turns, without any noticeable performance detrimention?.. I understood that deltas tend to lose energy faster.

Someone explain plz. There was a rant about F-16's STR few pages ago.


I'm not really aware of all the accurate data. @porky_kicker @Karthi. Little help?

Tejas demonstrated ,15-16 degree STR , minimum radius turn achieved 350 m. STR depends upon the corner speed also. The smooth manuvering of aircrafts is mainly because the pilots and tactics developer's studied the full potential of aircraft and designed manuvers according to the strength of Aircrafts . These figures will significantly reduce whenever they carry loads .
 

Karthi

Senior Member
Joined
Jul 15, 2018
Messages
2,214
Likes
17,753
Country flag
One thing that genuinely confuses me about Tejas is its turning. How come the pilots keep doing turns upon turns, without any noticeable performance detrimention?.. I understood that deltas tend to lose energy faster.

Someone explain plz. There was a rant about F-16's STR few pages ago.


I'm not really aware of all the accurate data. @porky_kicker @Karthi. Little help?

18 Km* 30 Km .please search for test results from pib may be helpful .
 

Bleh

Laughing member
Senior Member
Joined
Nov 23, 2017
Messages
6,175
Likes
25,855
Country flag
Tejas demonstrated ,15-16 degree STR , minimum radius turn achieved 350 m. STR depends upon the corner speed also. The smooth manuvering of aircrafts is mainly because the pilots and tactics developer's studied the full potential of aircraft and designed manuvers according to the strength of Aircrafts . These figures will significantly reduce whenever they carry loads .
Doesn't answer my question though. It goes on doing turns like that at completes all of them in 19-22 sec!.. How does that not decrease as many claim how deltas lose enerhy in repeated turns?
Is it due to the optimisations?.. I read in some interview that it doesn't have to be in a specific part of the envelope to perform its best, but tuned to minimise performance fluctuations with altitude & speed.

Anybody actually knows?.. or can ask HVT or AK?
How come the pilots keep doing turns upon turns, without any noticeable performance detrimention?.. I understood that deltas tend to lose energy faster.
 

Super lca

Tihar Jail
Banned
Joined
May 22, 2020
Messages
170
Likes
321
Country flag
Tejas demonstrated ,15-16 degree STR , minimum radius turn achieved 350 m. STR depends upon the corner speed also. The smooth manuvering of aircrafts is mainly because the pilots and tactics developer's studied the full potential of aircraft and designed manuvers according to the strength of Aircrafts . These figures will significantly reduce whenever they carry loads .
Is the str improved in the foc version?
 

Karthi

Senior Member
Joined
Jul 15, 2018
Messages
2,214
Likes
17,753
Country flag
Doesn't answer my question though. It goes on doing turns like that at completes all of them in 19-22 sec!.. How does that not decrease as many claim how deltas lose enerhy in repeated turns?
Is it due to the optimisations?.. I read in some interview that it doesn't have to be in a specific part of the envelope to perform its best, but tuned to minimise performance fluctuations with altitude & speed.

Anybody actually knows?.. or can ask HVT or AK?

Asking HVT will be the best cos he is a pilot and flown Tejas . Are you asking about energy manuverablity , then again the entire Manuvers designed to utilise the energy and minimise the energy bleed. Pilots usually have these charts , its almost impossible for civilians to get access on those doc's .

You will get basics of energy manuverablity here .

 

Karthi

Senior Member
Joined
Jul 15, 2018
Messages
2,214
Likes
17,753
Country flag
Is the str improved in the foc version?
STR is same not sure though, but Test pilots demonstrated more than what is allowed , it certainly not recommended cos it affects the airframe life .
 

Karthi

Senior Member
Joined
Jul 15, 2018
Messages
2,214
Likes
17,753
Country flag
Light aircraf
Doesn't answer my question though. It goes on doing turns like that at completes all of them in 19-22 sec!.. How does that not decrease as many claim how deltas lose enerhy in repeated turns?
Is it due to the optimisations?.. I read in some interview that it doesn't have to be in a specific part of the envelope to perform its best, but tuned to minimise performance fluctuations with altitude & speed.

Anybody actually knows?.. or can ask HVT or AK?
Light aircraft bleed energy slowly and gain energy slowly , heavy fighters can bleed and gain energy quickly. If an Aircraft loose energy pilot can use another manuvering to gain the energy , in Dogfight a low energy state may be dangerous . Please read the article I posted above
 

G10

Regular Member
Joined
Oct 10, 2015
Messages
461
Likes
621
Country flag
Light aircraf

Light aircraft bleed energy slowly and gain energy slowly , heavy fighters can bleed and gain energy quickly. If an Aircraft loose energy pilot can use another manuvering to gain the energy , in Dogfight a low energy state may be dangerous . Please read the article I posted above
Moment of inertia gone for a toss?
 

ashdoc

Senior Member
Joined
Jul 21, 2010
Messages
2,980
Likes
3,679
Country flag
Read the wiki page. Meticulously inserted everything, every faeture & achievements in there.
Updated the images too... Today only.
Can you tell me whether the plain tejas mk1 can carry derby missiles and how many can it carry.
 

Bleh

Laughing member
Senior Member
Joined
Nov 23, 2017
Messages
6,175
Likes
25,855
Country flag
Light aircraf

Light aircraft bleed energy slowly and gain energy slowly , heavy fighters can bleed and gain energy quickly. If an Aircraft loose energy pilot can use another manuvering to gain the energy , in Dogfight a low energy state may be dangerous . Please read the article I posted above
Not necessarily. F-18 is notorious for losing energy quickly & gaining slowly (from F-18 pilot on youtube). The Su-27 line is pretty draggy too.
On the other hand, Mirage-2000 is not that heavy...

Can you tell me whether the plain tejas mk1 can carry derby missiles and how many can it carry.
Max 4 without dual-racks. The outboard pylons should be able to carry Derby too but never seen such config.
 

Chinmoy

Senior Member
Joined
Aug 12, 2015
Messages
8,678
Likes
22,551
Country flag
I mean it's way too low for kaveri compared to ge404.
F404 has a bypass ratio of 0.34 while f414 has 0.25
M88 has 0.30
Compared to 0.16 for kaveri.

Back in 1980s ge404 was the most advanced engine for light / medium fighters in the world. So we tried to match the thrust of gef404 while compromising on fuel efficiency. ( As we couldn't match both )
A concept of leaky turbojet. Which is as good as a turbofan but not as advanced or fuel efficient as western contemporary turbofans .

See both f404 and m88 have almost double the bypass ratio of kaveri and both are most fuel efficient engines in their class.

At least this is my understanding . I could be wrong on this though so don't take it seriously.
You have just considered a single aspect over here. When we say that BPR of Kaveri is lower then M88 of GE engines, it means the air flow around the core in Kaveri is less then compared to others. Now increasing the flow MIGHT result in a more fuel efficient engine, but no where it would help Kaveri in its core.

Now looking at the fuel consumption rate, we could see that SFC of Kaveri in dry thrust is better then F 404 and at par with M88 i.e 0.78 lb/lb.h. Whereas in F-404 the military thrust SFC is of 0.81 lb/lb.h. The SFC of Kaveri increases during the wet thrust.

The most important aspect where Kaveri is lagging behind is in pressure ratio. Its pressure ratio of 21.5 is far behind the 24.5 and 26 of M88 and F-404 respectively. Unless we increase the pressure ratio, we can't expect to get the required thrust from the engine. Now interestingly the low BPR of Kaveri might be a plus point for a higher thrust. If you compare F-404 and F-414 BPR and pressure ratio, you would find that with a BPR of 0.25, the pressure ratio of F-414 is 30, which is way above then M88 and F-404. Its military thrust of 57 Kn is way above then 50 Kn of M88 and 49Kn of F-404.

So BPR wise, I believe Kaveri is just fine. We need to work on the entry temperature to increase the pressure ratio in turn to produce more thrust. Once we are able to do it, we could work on the BPR to make it more fuel efficient.
 

Latest Replies

Global Defence

New threads

Articles

Top