LCA News and Discussions

prabhug · Post by **prabhug** » 24 Oct 2011 11:13

ELCAA team managed to pull a event under its rug.Looks like it was grounded for months till they found the reason for the fuel leak.Looks like things are o.k and will fly again

karan_mc · Post by **karan_mc** » 24 Oct 2011 13:26

Philip wrote:In one of the recent issues of local mags,can't recollect which one,there was a small reference to the fact that the Mk-2 version,because of the modifications would be the equivalent of developing a "new aircraft".Ye Gods!

I think it was presumed earlier when news of changes to air intakes and other changes were predicated not to forget AESA for MK-2 , but in Aero India 11 every thing was put to rest , that with minimal changes to air frame it could perform better, even drdo staff whom i had meet there told me that first air frame will be ready by 2013 and first flight by 2014 , and by late 2016 production will start , he also pointed that aircraft will be tested on flight characteristics mainly due to modification carryout which requires software adjustment , when asked about AESA he told it will come for later variants , it seemed he was hinting at last batch of AESA equipped MK-2 (40) or MK-3 beyond 2020 .

Philip · Post by **Philip** » 24 Oct 2011 15:15

Tx, Karan.I can't understand why when small AESA radar's are available right now,Selex G and Phazatron,or even an Israeli one if available,why the intial versions can't fly with these radars until the desi version arrives? 2020 is aeons away and anyway the Super-Flanker ,FGFA and MMRCA will come with AESA radars within the next 5 years.What is the point in developing the LCA to finally prove itself to 1990's parameters ,two decades late? If its full development takes that long,it will certainly suffer the same fate of the HF-24,this time for want of an engine and a radar!

One must remember that massive amounts of manhours and scarce human resources are being spent on the LCA programme.Some time ago,due to the shortager of manpower,the same team looking after the IJT was asked to do duty for the FGFA! In such a situ,where scientific minds are a scarce commodity thanks to the demands form private industry too,one must ask the Q how best this scarce resource is being put to? I say this because AKA is reported in today's press as being unhappy with the MTA JV with Russia and the amount (lack) of Indian involvement in the project.But do we actually have the human resources in numbers and trained and experienced enough to be able to deliver on cutting edge tech? The galloping list of projects in the industry for aircraft and helos-apart from radars,missiles,avionics,etc. Unless the PSUs and private Indian industry work together and share the load there will be a widening gap in this commodity in India in the most challenging of all industries in the world,the aerospace industry,which is the "sunshine" industry in the country.

karan_mc · Post by **karan_mc** » 24 Oct 2011 18:32

@Philip , at Aero India 11 , i was expecting new Aesa radar been announced for MK-2 , but was shocked to see IAF / ADA / HAL sticking with MMR/2032 radar , when i asked another DRDO staffer , he had a simple answer , AESA for Tejas MK-2 won't be ready on time by the time MK-2 enters production , another ADA staffer who seemed like intern or new staff , told me its some thing to do with AMCA , what i think he hinted was AMCA and Tejas MK-2/3 blocks might have same or little modified AESA , having common technology . i have to point out that there is little clarity on AESA for Tejas MK2 or AMCA other then development of them with foreign help then again , only tenders were issued .

on Engine front , there seems to be little or no clarity , if AMCA first flight is expected by 2018 at best , then from where the engine will come ? Kaveri-2 with french will require 5 yrs in development ,then further ground test and then flight tests , i am pretty sure that they wont be ready for AMCA may be on production aircraft's .

Aditya_M · Post by **Aditya_M** » 24 Oct 2011 19:15

AESAs are expensive as hell, especially in the R&D phase. Trying to find the precision semiconductors for the MMICs required for each T/R module is a beast if you want to develop it all by yourself. On the other hand, passive arrays are easier to make; India has had the tech to make ferrite phase-shifters for a while now. I wouldn't be far off the mark if I said the R&D involved in making an AESA is of a similar level to that required for Tejas' FBW system (with only a reduced testing time cycle as flight safety checks will be fewer).

Rahul M · Post by **Rahul M** » 24 Oct 2011 20:24

welcome back !

suryag · Post by **suryag** » 25 Oct 2011 13:55

Flight test update
LCA-Tejas has completed 1717 Test Flights successfully. (21-Oct-2011).
(TD1-233,TD2-305,PV1-242,PV2-211,PV3-301,LSP1-67,LSP2-188,PV5-36,LSP3-45,LSP4-41,LSP5-48)

from

LCA-Tejas has completed 1713 Test Flights successfully. (14-Oct-2011).
(TD1-233,TD2-305,PV1-242,PV2-209,PV3-301,LSP1-67,LSP2-188,PV5-36,LSP3-43,LSP4-41,LSP5-48)

merlin · Post by **merlin** » 25 Oct 2011 17:13

The LCA should have already hit another milestone - 1000 hours combined.

Cain Marko · Post by **Cain Marko** » 27 Oct 2011 04:51

At this point in time - a non AESA/IRST LCA is fine - this is the bottom level fighter in the IAF anyways, backed with AWACS and newly devloped mech radars, it should easily hold its own against the likely foes - blk 52s/J10/JF17s. Just get it moving and inducted in doublequick time. Screw the fancy-schmancy goodies. A good MLU around 2025 would be excellent, they'l probly have mature homegrown engines, AESAs and optics by then.

Right now an HMS, a good BVR missile, and solid kinetic performance is more important imho. Toys can come later.

CM.

suryag · Post by **suryag** » 27 Oct 2011 09:39

LCA NP1 update

SaiK · Post by **SaiK** » 27 Oct 2011 20:25

In September 2010, we observed that the undercarriage was over-sized. ... This is a very critical piece with the hitting impact on the ship going to be much higher,”

“We will fly the NP-I with the same undercarriage making some slight corrections. If a lighter undercarriage has to be integrated at this stage, it will delay the programme further. We cannot rush the project. Young boys are putting their hearts out and working seven days a week. Making planes are not child's play,”

1. Political pressures should not side step to look at defects in design or testing.
2. We have to start using simulation world big time to design everything in super computers including weights, t:w, wind tunneling, and aerodynamics. May be we should begin from experiences, and begin a brave new simulated world.
3. A gift coming late, but well designed for the future is the real gift.

bottom line, AKA/public show and satisfaction should not supersede critical aspects of the NP1 needs.

RKumar · Post by **RKumar** » 28 Oct 2011 13:38

LCA-Tejas has completed 1717 Test Flights successfully. (21-Oct-2011).
(TD1-233,TD2-305,PV1-242,PV2-211,PV3-301,LSP1-67,LSP2-188,PV5-36,LSP3-45,LSP4-41,LSP5-48)

LCA-Tejas has completed 1713 Test Flights successfully. (14-Oct-2011).
(TD1-233,TD2-305,PV1-242,PV2-209,PV3-301,LSP1-67,LSP2-188,PV5-36,LSP3-43,LSP4-41,LSP5-48)

1 week and 4 test flights ... seems like something in going on with PV2 only

AdityaEngineer · Post by **AdityaEngineer** » 29 Oct 2011 16:37

@SaiK A look at HAL Nashik labs told me one thing they have got a CFD Analyzer there that is a full blown software but it works on the basis of Navier-Stoke's Equatand not on basis of Reynold's Equation i.e. it avoids the compressible fluid force that is acting on the body.If status at this moment in cfd tech is this then i really think that simulation is far off.

Karan M · Post by **Karan M** » 29 Oct 2011 23:49

Philip wrote:Tx, Karan.I can't understand why when small AESA radar's are available right now,Selex G and Phazatron,or even an Israeli one if available,why the intial versions can't fly with these radars until the desi version arrives? 2020 is aeons away and anyway the Super-Flanker ,FGFA and MMRCA will come with AESA radars within the next 5 years.What is the point in developing the LCA to finally prove itself to 1990's parameters ,two decades late? If its full development takes that long,it will certainly suffer the same fate of the HF-24,this time for want of an engine and a radar!

1. Whats the point of putting a small AESA radar? Just for the sake of buzzwords or bragging rights?
2. The MiG-29 Upg, MiG-29K, Mirage 2000, Jaguar DARIN-3, SHar upgrade all have MSAs. Can you explain why the LCA MK1 or even early MK2s need an AESA given the fact that its ~650mm radar dish is in the class of the larger fighters above & its RCS is lower - translating to the fact that it will have an overall performance equal to the above aircraft.
3.There is no statement saying that the 2020 LCA will have a MSA either.
4. In production MSAs continue to have advantages over in producion AESAs in terms of performance to weight, power consumption, and scan angles.

tsarkar · Post by **tsarkar** » 30 Oct 2011 07:44

From what I understand, only US AESA radars have reached a degree of maturity and reliability. The European, Russian or Israeli ones on offer have not completed development and will require significant Indian investment. The Rafale & Eurofighter "should" have an AESA by the time they enter IAF service, and while details are not available, Indian investments "might" go into those radars as well. Radar ToT is an essential part of MMRCA initiative, so I dont think India will look elsewhere for the time being.

SaiK · Post by **SaiK** » 30 Oct 2011 08:35

Well.. I don't think Indian investment will go into Rafale or EF2K AESA

arijitkm · Post by **arijitkm** » 31 Oct 2011 18:25

Tejas MK-3 is it on?

http://idrw.org/?p=4903

member_20033 · Post by **member_20033** » 31 Oct 2011 20:05

According to me we wont see AMCA before 2025. Therefore we will see many newer version of LCA mark III, mark IV with improvements in Engines, Avionics, Radars etc which will make them a true 4 ++ generation fighter unless we get FGFA (2020's) and AMCA 2025's

vishnu.nv · Post by **vishnu.nv** » 01 Nov 2011 11:31

All the future variants of LCA will depend on the fact that how fast the HAL can produce the aircraft.
The IAF has requirements for LCA class of aircraft, but they are not going to wait for ever for the aircraft. As the LCA delays its orders will be eaten up by MRCA and FGFA aircraft's.

Kersi D · Post by **Kersi D** » 01 Nov 2011 12:11

AdityaEngineer wrote:@SaiK A look at HAL Nashik labs told me one thing they have got a CFD Analyzer there that is a full blown software but it works on the basis of Navier-Stoke's Equatand not on basis of Reynold's Equation i.e. it avoids the compressible fluid force that is acting on the body.If status at this moment in cfd tech is this then i really think that simulation is far off.

We speak only English and BRFese. What language are u talking ? Cannot undertsand a word ????

Your mail sounds interesting. Please translate it into English + BRFese

Yours Ignorantly
K

adityadange · Post by **adityadange** » 01 Nov 2011 13:13

@KersiD
as i understood, what he means is HAL Nasik lab has a s/w which analyses computational fluid dynamics required to analyse aircraft performance (most likely w.r.t aerodynamics). now that particular s/w uses Navier-Stoke's Equatand method for analysis. but it does not consider certain aspects (i.e. compressible fluid force). On the other hand Reynold's Equation considers that thing.
To make a simulator one probably needs a s/w that uses Reynold's Equation method. (seems like Reynold's Equation is more accurate method). if HAL is not using such advanced/more accurate method they are not able to make a simulator for analyzing aircraft simulator.

P.S. please dont be harsh on me if i am talking nonsense. i am quite new here.

rajanb · Post by **rajanb** » 01 Nov 2011 13:20

My question is what has Nashik got to do with the LCA. Nashik has been primarily for Ru a/c. It depends on what ADA and HAL BLR have? Nashik may be having older equipment, which has nothing to do with the LCA.

Also, I know for sure that HAL/NAL share facilities. And ADA must also be in the mix.

I have been to the Virtual Reality Lab at ADA. It blew my mind as to the simulation they could achieve. Also saw the demo of the LCA.

On CAD/CAM they were using the standard Catia, but for rendering they were using a fabulously efficient SW which was jointly developed by IISc and Stanford University.

Avinash Rav · Post by **Avinash Rav** » 01 Nov 2011 13:42

adityadange wrote:@KersiD
now that particular s/w uses Navier-Stoke's Equatand method for analysis. but it does not consider certain aspects (i.e. compressible fluid force). On the other hand Reynold's Equation considers that thing.
To make a simulator one probably needs a s/w that uses Reynold's Equation method. (seems like Reynold's Equation is more accurate method). if HAL is not using such advanced/more accurate method they are not able to make a simulator for analyzing aircraft simulator.

Correct me if I am wrong. Reynolds equation models are used for thin film simulations(like in lubrication etc) which can be considered quasi 2-D. But the N-S models are best for 3-D aerodynamic simulations.

adityadange · Post by **adityadange** » 01 Nov 2011 14:55

Avinash Rav wrote: Correct me if I am wrong. Reynolds equation models are used for thin film simulations(like in lubrication etc) which can be considered quasi 2-D. But the N-S models are best for 3-D aerodynamic simulations.

I am afraid i am not the expert one on this subject. all i did was rephrase AdityaEngineer's post as per my understanding. I think he is better person to answer your query (and to correct me if i have written something wrong.).

suryag · Post by **suryag** » 03 Nov 2011 21:04

Flight test update

LCA-Tejas has completed 1718 Test Flights successfully. (28-Oct-2011).
(TD1-233,TD2-305,PV1-242,PV2-211,PV3-301,LSP1-67,LSP2-188,PV5-36,LSP3-46,LSP4-41,LSP5-48)

from

LCA-Tejas has completed 1717 Test Flights successfully. (21-Oct-2011).
(TD1-233,TD2-305,PV1-242,PV2-211,PV3-301,LSP1-67,LSP2-188,PV5-36,LSP3-45,LSP4-41,LSP5-48)

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

adityadange, you did bring out the technical aspect of what mr. engineer was talking. what kesari d says, could you both, and if possible avinash rav consider coming out more on the subject and say what you all think that we need to do for simulation?

basically, we should do very similar works like how boeing or lm may do in their simulation world. they can create a product, fly it, take metrics and destroy it.

can we do that?

saps · Post by **saps** » 03 Nov 2011 22:58

From the first hand experience of HAL-BIT build simulators...........there is still a long way to travel forward before we reach globally acceptable standards.

Any developments to enhance knowledge are welcome.

cheers

Kersi D · Post by **Kersi D** » 03 Nov 2011 22:58

adityadange wrote:@KersiD
P.S. please dont be harsh on me if i am talking nonsense. i am quite new here.

This is a defence forum.

We live by sword and die by it.

You will have to go through trial by fire. R

Real fire - not some junk 30 m long aluminum tube and called agni by some people".

Kersi

Hey I am joking !!

Don't take anything seriously on this forum

Kersi D · Post by **Kersi D** » 03 Nov 2011 23:02

adityadange wrote:@KersiD
as i understood, what he means is HAL Nasik lab has a s/w which analyses computational fluid dynamics required to analyse aircraft performance (most likely w.r.t aerodynamics). now that particular s/w uses Navier-Stoke's Equatand method for analysis. but it does not consider certain aspects (i.e. compressible fluid force). On the other hand Reynold's Equation considers that thing.
To make a simulator one probably needs a s/w that uses Reynold's Equation method. (seems like Reynold's Equation is more accurate method). if HAL is not using such advanced/more accurate method they are not able to make a simulator for analyzing aircraft simulator.

So is there any advantage on software based on Reynold's equation vis-a-vis Navier Stokes equation ??

If yes then why the f%#k HAL does not get the right/better/best software ? (And we r a "software superpower")

If you are aware of any advantages then you must educate us morons.

K

Gurneesh · Post by **Gurneesh** » 03 Nov 2011 23:05

Navier-Stokes Eq. is just momentum conservation. Hence it is the most basic (and thus the truest form). Errors occur when one starts making approximations (boundary conditions, initial conditions, forces, viscosity etc). You can configure your NVS for compressible or incompressible flow, for viscous or inviscid flow etc.

In fluid dynamics, use of Navier-Stokes is thus imperative. Any and all cfd models will use NVS.

Depending on the system one is looking at, you impose conditions on the NVS Eq. and combine it with other fundamental equations like conservation of mass (continuity eqn.), conservation of energy, species etc.

So, the Reynolds equation so often mentioned in this page is nothing but NVS combined with continuity eqn when imposing boundary conditions of two closely placed parallel surfaces with a fluid flow in between them. You also use some assumptions that simplify the equations a lot (which is what is done to get Reynolds Eqn). Dunno how an airplane cfd model would benefit from this model.

http://www.math.udel.edu/~pelesko/Teach ... nal%29.pdf

Similarly if you want to solve for a turbulent flow, you take the conservation eqns and apply Reynolds Averaging to it. RANS (reynolds averaged navier-stokes) is a de-facto starting point for turbulent models.

So in a nutshell, NVS eqns will give the most accurate result. But you cannot solve such a system as the number of variable are more than the number of equations. Which is why approximations and simplifications are needed. People these days do use DNS (Direct Numerical Simulation) on complete NVS equations, but that has severe penalties on required time and computational resources.

SaiK · Post by **SaiK** » 03 Nov 2011 23:53

so that kind of throws some light on for modeling CFD specific attributes. what about say weight of an a/c? or thrust : weight ratio? how would one simulate that?

Gurneesh · Post by **Gurneesh** » 04 Nov 2011 05:20

Thrust and weight will feature in the force balance. CFD will give the drag values in a particular a/c state (direction of motion, speed etc.), weight will come in as gravitational force as well as inertia. Since the item of interest in a/c and not air, mainly the surface forces (drag, lift) will be if interest to a CFD programmer. While in an inlet, the air flow profile is also very important.

Thrust is the total available force. So a simple point mass model will give acceleration to be total force (thrust + gravity force + drag + lift) divided by mass. Thrust will always be positive and drag always negative and so on.

One can then start adding complexities to get more accurate results.
1) For a plane of finite dimensions then we need to distribute the forces across the surface due to which moments will come in (bringing with them angular momentum etc).

2)The thrust will vary depending on airflow in the inlets etc.

3) Plane weight distribution will change due to fuel moving in the tanks.

.
.
.

Expert programmers wouldn't start from point mass analysis, but with a fairly complex model which gives intended accuracy from starting.

AdityaEngineer · Post by **AdityaEngineer** » 04 Nov 2011 20:10

Hello Bashers,Total force=(grav+pres+vis+tur+com),Reynolds eqn=(grav+pres+vis+tur),NS Eqn=(grav+pres+vis),not considering turbulent force during cfd will cause results to be inaccurate.Also cfd analyzer can b used to simulate full air shows without spending a drop of aviation fuel.Thanks.

Lalmohan · Post by **Lalmohan** » 04 Nov 2011 21:56

Navier Stokes, euler methods, etc., are useful for developing detailed engineering views of airflows. the computational demands are way too high for using them in flight simulator models. mostly the latter use flight test data (or approximations thereof depending on the maturity of the programme) to drive look up table based iterative F=m.a calculations using 6 degrees of freedom and 2nd derivatives of lift, drag, thrust and weight parameters
the flight performance accuracy using the latter method is pretty darned good
the former remains very much for determining flow and loading at the early design stage

Dennis · Post by **Dennis** » 04 Nov 2011 22:40

AdityaEngineer,
Please educate yourself a little more on CFD. And please re-read what Gurneesh has said carefully.

NS equations govern *all* fluid mechanics. If a software can fully solve NS equations, it would be the best tool to use for all fluid dynamics purposes. No such tool/software exists today.
NS equations are simplified by making various assumptions for viscosity, randomness(turbulence), compressibility etc. These simplified equations are what are used by existing CFD packages.
A subset of these simplified equations, Reynolds Averaged NS (RANS) equations, are used to simulate turbulent flows. Most widely used CFD software use RANS solvers for practical applications today.
Other techniques/simplifications of NS equations, like Direct numerical simulations (DNS), Large Eddy Simulation (LES), etc are extremely computationally intensive and are mostly used in academic research.

There is no such thing as Reynold Equation that is used for aircraft design or CFD in support of aircraft design. It may be used for modeling flows in some machine elements, but that is far removed from aircraft design.

CFD generates the flow field around an object (an airplane, for example) - velocities, pressures, stresses etc. These flow parameters have to be integrated (as a result, smoothed) and converted to forces, moments etc on the body to be used in a force balance, like Gurneesh explained. Because of this, RANS based CFD is sufficient for most practical applications today.

Vivek K · Post by **Vivek K** » 05 Nov 2011 00:42

How are all these posts relevant to LCA. Pls check with Adminullahs and start a simulation thread to discuss this. Let us have LCA i.e. LSP, NP1, flight test etc discussion/news here!

Katare · Post by **Katare** » 05 Nov 2011 05:26

LCA was given IOC with several concessions and IAF called it IOC-1 with full IOC (or IOC-2) due on mid 2011. Did they ever got it cleared?

Gurneesh · Post by **Gurneesh** » 05 Nov 2011 06:27

^^^ The only reports of tests were the bombing runs in Pokhran. Other than that only new news was of all a/c getting very little mileage due to fuel lines rubbing against oil lines and leaking. They have solved that. Last we heard LSP7 was about to fly.

Regarding IOC in Jan11, main testing points that should have been covered but were not included :
a) Wake Tests (a/c flies close behind another a/c).
b) Lightening Strike tests.
c) All Weather Clearance.

There is no info on whether any of these have been completed.

Gurus, is anything else missing in this list.

For FOC, the following was to be concluded
a) Integration of BVR, guns, rockets, guided and unguided bombs
b) AoA to 24 deg from 22 deg.
c) expansion of flight envelop to -3.5G - +8G (from -2 to 6G)

The bomb thing seems to have been done at Pokhran. The only tests that ADA could run are BVR, rockets and guns as AOA and High G trials were to be conducted on LSP6 (which has the spin recovery chute).

Source: http://livefist.blogspot.com/2011/01/ia ... wants.html

rajanb · Post by **rajanb** » 12 Nov 2011 09:37

Guys,

it has been a long time since I saw the LCA grace the skies at Bangalore. Any news?

suryag · Post by **suryag** » 12 Nov 2011 10:07

Avid golfers any yellow painted LCA doing taxi runs ? May be that some of the LCAs are on an outing in Goa/Leh firing their missiles