Bharat Rakshak Forum Announcement

Hello Everyone,

A warm welcome back to the Bharat Rakshak Forum.

Important Notice: Due to a corruption in the BR forum database we regret to announce that data records relating to some of our registered users have been lost. We estimate approx. 500 user details are deleted.

To ease the process of recreating the user IDs we request members that have previously posted on the BR forums to recognise and identify their posts, once the posts are identified please contact the BRF moderator team by emailing BRF Mod Team with your post details.

The mod team will be able to update your username, email etc. so that the user history can be maintained.

Unfortunately for members that have never posted or have had all their posts deleted i.e. users that have 0 posts, we will be unable to recreate your account hence we request that you re-register again.

We apologise for any inconvenience caused and thank you for your understanding.

Regards,
Seetal

Kaveri & aero-engine discussion

The Military Issues & History Forum is a venue to discuss issues relating to the military aspects of the Indian Armed Forces, whether the past, present or future. We request members to kindly stay within the mandate of this forum and keep their exchanges of views, on a civilised level, however vehemently any disagreement may be felt. All feedback regarding forum usage may be sent to the moderators using the Feedback Form or by clicking the Report Post Icon in any objectionable post for proper action. Please note that the views expressed by the Members and Moderators on these discussion boards are that of the individuals only and do not reflect the official policy or view of the Bharat-Rakshak.com Website. Copyright Violation is strictly prohibited and may result in revocation of your posting rights - please read the FAQ for full details. Users must also abide by the Forum Guidelines at all times.
Neela
BRF Oldie
Posts: 3460
Joined: 30 Jul 2004 15:05
Location: Spectator in the dossier diplomacy tennis match

Re: Kaveri & aero-engine discussion

Postby Neela » 06 Mar 2017 17:57

IDRW has a screengrab video of HTFE at full thrust.

abhijitm
BRF Oldie
Posts: 2696
Joined: 08 Jun 2006 15:02
Contact:

Re: Kaveri & aero-engine discussion

Postby abhijitm » 06 Mar 2017 18:16

Why not contact Boeing to hire their testbed?

JayS
BRF Oldie
Posts: 2043
Joined: 11 Aug 2016 06:14

Re: Kaveri & aero-engine discussion

Postby JayS » 06 Mar 2017 18:21

BTW has anyone posted this, that HTSE-1200 design is completed, prototype is in making and HAL is targeting to fire it up by end of 2017.

NRao
BRF Oldie
Posts: 15604
Joined: 01 Jan 1970 05:30
Location: Illini Nation

Re: Kaveri & aero-engine discussion

Postby NRao » 06 Mar 2017 18:36

JayS wrote:BTW has anyone posted this, that HTSE-1200 design is completed, prototype is in making and HAL is targeting to fire it up by end of 2017.


Does the number have a meaning? And if so what? Perhaps the thrust, but in what units?

JayS
BRF Oldie
Posts: 2043
Joined: 11 Aug 2016 06:14

Re: Kaveri & aero-engine discussion

Postby JayS » 06 Mar 2017 18:40

NRao wrote:
JayS wrote:BTW has anyone posted this, that HTSE-1200 design is completed, prototype is in making and HAL is targeting to fire it up by end of 2017.


Does the number have a meaning? And if so what? Perhaps the thrust, but in what units?


1200 kW power.

Rakesh
Webmaster BR
Posts: 3068
Joined: 15 Jan 2004 12:31
Location: Planet Earth
Contact:

Re: Kaveri & aero-engine discussion

Postby Rakesh » 08 Mar 2017 05:51

An article from Feb 2017...

India’s Ghatak Stealth UCAV Moves Forward, Likely With Dassault
http://www.livefistdefence.com/2017/02/ ... rward.html

A total of approximately $450 million will be spent from the Indian side in bringing the Kaveri engine to satisfactory operating standards through a tech partnership with France’s Snecma as part of committed offsets from the Indian Rafale contract. Top sources confirm that the technology infusion from France intends to make the Kaveri a standard engine for the LCA Tejas, to assist its modification for the Ghatak and for twin-configuration on the AMCA.

Cybaru
BRFite
Posts: 1808
Joined: 12 Jun 2000 11:31
Contact:

Re: Kaveri & aero-engine discussion

Postby Cybaru » 08 Mar 2017 13:13

We could repurpose one of the retired tu 142 for engine testing. The missile pylons that carry ashm are strong enough to take on an engine. Possible???

shiv
BRF Oldie
Posts: 32534
Joined: 01 Jan 1970 05:30
Location: Pindliyon ka Gooda

Re: Kaveri & aero-engine discussion

Postby shiv » 08 Mar 2017 13:28

Rakesh wrote:An article from Feb 2017...

India’s Ghatak Stealth UCAV Moves Forward, Likely With Dassault
http://www.livefistdefence.com/2017/02/ ... rward.html

A total of approximately $450 million will be spent from the Indian side in bringing the Kaveri engine to satisfactory operating standards through a tech partnership with France’s Snecma as part of committed offsets from the Indian Rafale contract. Top sources confirm that the technology infusion from France intends to make the Kaveri a standard engine for the LCA Tejas, to assist its modification for the Ghatak and for twin-configuration on the AMCA.

I am suspicious of any article that claims that nation x or company y will magically make Kaveri OK

srai
BRF Oldie
Posts: 3422
Joined: 23 Oct 2001 11:31

Re: Kaveri & aero-engine discussion

Postby srai » 08 Mar 2017 18:32

^^^

Kaveri is mostly ready. It needs that "last-mile" help from an experience partner to get it over the hump.

devesh
BRF Oldie
Posts: 5103
Joined: 17 Feb 2011 03:27

Re: Kaveri & aero-engine discussion

Postby devesh » 08 Mar 2017 22:03

An appropriate question: what incentive does France have to help India overcome US engine monopoly of GE?

Secondly, US and France are treaty partners and firmly within the Atlanticist alliance. Why would one of them help break the monopoly of the other in military tech to a 3rd party which continues to buy from them both in billions of $$?

NRao
BRF Oldie
Posts: 15604
Joined: 01 Jan 1970 05:30
Location: Illini Nation

Re: Kaveri & aero-engine discussion

Postby NRao » 08 Mar 2017 22:23

devesh wrote:An appropriate question: what incentive does France have to help India overcome US engine monopoly of GE?

Secondly, US and France are treaty partners and firmly within the Atlanticist alliance. Why would one of them help break the monopoly of the other in military tech to a 3rd party which continues to buy from them both in billions of $$?


Neither is doing anything beyond getting AN engine to work under very small parameters (compared to what each of them can do). After both these exercises India will be where they are today - give and take some - with two workable engines. Would India be able to design and produce the next gen engine? I do not think so. Both will make sure that the status quo is maintained.

Note that all France has promised is a kaveri engine to mate with the LCA. They have been saying that since 2008-9.

The US wanted a Brahmos type of a deal. India proposed an engine.

Both are one shot deals. Great within themselves. Nothing more.

SaiK
BRF Oldie
Posts: 35251
Joined: 29 Oct 2003 12:31
Location: NowHere

Re: Kaveri & aero-engine discussion

Postby SaiK » 09 Mar 2017 07:13


shiv
BRF Oldie
Posts: 32534
Joined: 01 Jan 1970 05:30
Location: Pindliyon ka Gooda

Re: Kaveri & aero-engine discussion

Postby shiv » 09 Mar 2017 07:50

srai wrote:^^^

Kaveri is mostly ready. It needs that "last-mile" help from an experience partner to get it over the hump.

I have heard about this in the past from people who were in the business. Mostly the experienced partner can only say "try this" or "try that". Or maybe they have some testing facilities that we don't (I hate that! That the fk have we been doing all these decades?) Such help does not always lead to an easy solution. It helps but it may still mean an uncertain period of development.

That is why I protest at hearing a confident statement in the press that "Help from Snecma will make things OK". If things were that simple they would have become OK long ago. I hate it when the press reports that "help from xyz" will solve issues. They will help, but not necessarily solve. It only fools us into thinking that the end of the tunnel is near.

habal
BRF Oldie
Posts: 5885
Joined: 24 Dec 2009 18:46

Re: Kaveri & aero-engine discussion

Postby habal » 09 Mar 2017 08:48

shiv wrote:
Rakesh wrote:An article from Feb 2017...

India’s Ghatak Stealth UCAV Moves Forward, Likely With Dassault
http://www.livefistdefence.com/2017/02/ ... rward.html


I am suspicious of any article that claims that nation x or company y will magically make Kaveri OK


there's no need to be suspiscious. What it really means is that the platform is mature and lot of players have arrived to take credit and bask in the glory. Success has many friends, failure is very lonely and all that.

Singha
BRF Oldie
Posts: 58784
Joined: 13 Aug 2004 19:42
Location: X,L,S,VHF band radars fully on

Re: Kaveri & aero-engine discussion

Postby Singha » 09 Mar 2017 08:55

An appropriate question: what incentive does France have to help India overcome US engine monopoly of GE?


^^^ ge pw saturn have no real need for indic market to survive. Their domestic needs and cheen on the sly are huge.

What is the fate of snecma? Other than replacement engine of rafale the eu has no 5th gen proj and even if it did the rr and mtu would corner spoils like in ej200.

Their lifeline could be developing a large ge414epe class engine for amca and fgfa and tejas mk3 needs a customer base that will last 50 years.

French govt can ofcourse throw thm bailout deals but inevitably the manufacturing aspects will wither. The rafale line is already a pittance vs the jsf production.

I am not sure how france wants to retain its place as a tier1 aerospace power.

habal
BRF Oldie
Posts: 5885
Joined: 24 Dec 2009 18:46

Re: Kaveri & aero-engine discussion

Postby habal » 09 Mar 2017 09:45

Is GTRE having problem productionizing kaveri ? Or do they envision such problems in future and have cautiously decided that they need some hand-holding here, because when the cheeni productionized their AL-31 clone WS-10A/B/C they had encountered many issues with engine performance in real time conditions. They had engines copies failing in mid-flight eventhough they had passed all flight hour endurance tests.

I do not underestimate the approach of GTRE or overestimate it. They are doing a fair job with available resources.

Cybaru
BRFite
Posts: 1808
Joined: 12 Jun 2000 11:31
Contact:

Re: Kaveri & aero-engine discussion

Postby Cybaru » 09 Mar 2017 10:06

Something in response to the FGFA and its issues around engine that I posted in another thread in response to the FGFA. Perhaps the Kaveri thread is a better place for it.

cybaru wrote:It seems to be the engine in every report.

Safran has to figure out a market for its engines or it wil lose the race and won't be able to keep up with American and Russian articles of future. It needs to be able to seek a market more than the 200/300 rafales that will be produced that it currently has.

For it to survive, it needs to partner or compete in another market which is as big or bigger. In my opinion the fgfa, amca and LCA engines provide a unique opportunity to safran to capture a new market. We have a need and they need to be able to compete and remain relevant in the future.

I would think that this should be our push. We partner with safran to create an engine. I also think that majority of 4 billion dollars we give will go straight to the engine. If that's the case, we take the fgfa as is and reserve the right to change out the engine with our own efforts later. We negotiate the costs to a lower number and push more into our own efforts towards creating a line of engines that we we research, manufacture and support in long run.

This allows us to fall back on Russian engines if our efforts don't pan out or get delayed.

shiv
BRF Oldie
Posts: 32534
Joined: 01 Jan 1970 05:30
Location: Pindliyon ka Gooda

Re: Kaveri & aero-engine discussion

Postby shiv » 09 Mar 2017 10:31

Cybaru wrote: We partner with safran to create an engine.

All successful engine making companies will have ready made core engine designs that can create a new engine at short notice. They will give us the designs, the tolerances and export the materials to us. They will not come to India and handhold Indian factory floor workers in metal forges and tell us what proportion of iron/carbon/copper/titanium/chromium whatever goes into the metal and at what temperatures and other physical conditions are required to make it.

They will also not tell us why they selected blade length of 11 cm in turbine core and not 11.5 cm. They will not tell us the calculations that went into reaching that decision and what would happen if we changed the dimensions and the materials.

In short it will be sophisticated screwdrivergiri giving us no increase in basic ability to design our own engine. Transfer of technology is transfer if experience and human skills. No one does that, but we don't seem to understand that.

We need to work out the steps on our own. Even China is struggling here because copying is not working.

rohiths
BRFite
Posts: 385
Joined: 26 Jun 2009 21:51

Re: Kaveri & aero-engine discussion

Postby rohiths » 09 Mar 2017 10:39

Based on whatever I know, the difficulty India is facing in engines is from metallurgy and manufacturing at the required tolerances. The design part is pretty figured out

Cybaru
BRFite
Posts: 1808
Joined: 12 Jun 2000 11:31
Contact:

Re: Kaveri & aero-engine discussion

Postby Cybaru » 09 Mar 2017 10:41

Dead on shiv! I agree with you. It will be screwdriver giri for now, but as long as we don't give up making it ourselves, it is far better than a fully assembled engine.

I do say we continue to work on our own core separately, but now produce 85% of the engine inhouse with our own parts made in India and perhaps a safran core. This way we know what parts need to be replaced when and how to make it better and have rest of the engine working and debugged.

There is little value in this now, but as we progress and feel confident to swap in our own core, we would have had a debugged and working engine and know where to focus. We may lose some efficiencies because we are not burning fuel as efficiently as the other cores will, but thats a battle for another day. Although it may take time to catchup with and create and efficient core like our friends may have, but it will be our own engine. The inefficiencies can be dealt with by adding in extra margin in the fuel carried to begin with during design phase. The cost of extra fuel and the savings from making the core ourselves will be a wash for all accounting/operating/capex purposes.

Rakesh
Webmaster BR
Posts: 3068
Joined: 15 Jan 2004 12:31
Location: Planet Earth
Contact:

Re: Kaveri & aero-engine discussion

Postby Rakesh » 09 Mar 2017 20:55

cybaru: +108 to you! Well said.

Rakesh
Webmaster BR
Posts: 3068
Joined: 15 Jan 2004 12:31
Location: Planet Earth
Contact:

Re: Kaveri & aero-engine discussion

Postby Rakesh » 09 Mar 2017 21:56

Read this article below. Very interesting read!

Indian Kaveri Turbofan’s Last Mile Problem: A Mystery Noise
http://www.livefistdefence.com/2017/03/ ... noise.html

A Kaveri engine sporting potential commonality with the Snecma M88 could be compelling factor in how India chooses its next fighter jets, both for the Indian Air Force and Indian Navy. Those implications, at any rate, would be clearer only once the Kaveri proves itself at every level of performance and envelope.

The above is why the Snecma-Safran deal with GTRE is causing heartburn for some folks on BRF :)

habal
BRF Oldie
Posts: 5885
Joined: 24 Dec 2009 18:46

Re: Kaveri & aero-engine discussion

Postby habal » 10 Mar 2017 08:17

2 or 3 points

1. firstly the info in public domain seems to be always one step behind what happens on site. Noise flutter issue was resolved as per a gtre tech on aero show 2017. So issue was to integrate kaveri with LCA as setoff for Rafale deal.

2. Neither mettalurgy nor design is anymore the issue. Deisgn is not the issue because since the day kaveri was started and today, there have been large jumps in cad/cam simulation and computing capabilities with even TCS pitching in to help develop next gen engine on boeing. There is substantial flow of design knowledge today than a decade ago and this will help design and not hinder it. Coming to mettalurgy mdl association with Russia also helps in knowledge base for mettalurgy. Ofcourse IP is protected, but cross polination of ideas can never be constrained.

3. So my conclusion is that the tie-up with safran is about very specific and measurable stuff like integration with LCA and integration of kaveri with rafale as test bed. These are very specific, achievable, deliverable, measurable goals non-delivery of which can attract specific penalities and invoke specific non-performance clause and subsequent downgrading.

Yagnasri
BRF Oldie
Posts: 8820
Joined: 29 May 2007 18:03

Re: Kaveri & aero-engine discussion

Postby Yagnasri » 10 Mar 2017 09:20

One serious mango question - Sorry in advance. If we are looking for integration with LCA in two years and two more years ( my timeline. I do not know how much time it takes to test it) then should we not plan to have a regular production capability planned in advance. Not suppliers but land buildings etc at least. Even suppliers etc with greater flexibility in their contracts for any changes required to be made after testing is done and product is approved.

Neela
BRF Oldie
Posts: 3460
Joined: 30 Jul 2004 15:05
Location: Spectator in the dossier diplomacy tennis match

Re: Kaveri & aero-engine discussion

Postby Neela » 10 Mar 2017 18:26

Crucial Engine For India’s Cruise Missiles Revs Up

Livefist has learnt that the Nirbhay cruise missile, currently powered by an NPO Saturn 36MT turbofan, will next be tested in the May-June period using a turbojet engine. While the GTRE has been mandated with proving the Manik turbofan by the time the Nirbhay’s other flight systems are proven, top sources confirm a Nirbhay test powered by a Manik engine could take place by the end of next year. The Manik turbofan has been under rigirous ground and high power tests for over two years now, and scientists are understood to be satisfied with progress. Current activity includes work spread between GTRE and the National Aerospace Laboratory. At the latter’s Propulsion Division, Manik components including its fan, centrifugal compressor, high pressure and low pressure turbines and alternator are under test.

At 425 kgF (kilogram-force) of thrust, scientists are working to reduce the Manik turbofan’s current 110 kilogram total weight. The engine makes major use of the Mishra Dhatu Nigam-developed MDN 321 special steel and special indigenous alloys. The Manik engine has only ever been displayed as a rapid-prototyping model at shows:


Plus more details in the article on engine test infractructure ( the tender which Indranil posted for twin-test-cell for 130kN class engines) and also nuggets on 3-stage LRCM , which Dr.Christopher mentioned ( booster eject , turbofan cruise and supersonic ramjet end-phase )

SaiK
BRF Oldie
Posts: 35251
Joined: 29 Oct 2003 12:31
Location: NowHere

Re: Kaveri & aero-engine discussion

Postby SaiK » 10 Mar 2017 19:32

Yagnasri wrote:One serious mango question - Sorry in advance. If we are looking for integration with LCA in two years and two more years ( my timeline. I do not know how much time it takes to test it) then should we not plan to have a regular production capability planned in advance. Not suppliers but land buildings etc at least. Even suppliers etc with greater flexibility in their contracts for any changes required to be made after testing is done and product is approved.

Yag ji, you are jumping the gun. I'd not think even production jigs for this needs investments. The 83kN max wet thrust is yet not achieved and proved. 2 years probably an estimate to tell what precisely is wrong (guesses - multivariable) and not to port into LCA, which is MSM mischief.

the main irritant is only failure reports are aplenty on the web

kapilrdave
BRFite
Posts: 1524
Joined: 17 Nov 2008 13:10

Re: Kaveri & aero-engine discussion

Postby kapilrdave » 10 Mar 2017 20:15

I have a question which could well be the stupidest question asked on Kaveri, but I couldn't resist the curiosity.

For high altitude tests why can't we use heavy choppers (say Chinook) to lift it along with fuel to high altitude? Use multiple choppers if required.

Neshant
BRF Oldie
Posts: 4071
Joined: 01 Jan 1970 05:30

Re: Kaveri & aero-engine discussion

Postby Neshant » 13 Mar 2017 05:50

Because there is no 50,000ft mountain top..

High altitude tests involve having the engine power a moving plane, not sitting statically atop a mountain.

shiv
BRF Oldie
Posts: 32534
Joined: 01 Jan 1970 05:30
Location: Pindliyon ka Gooda

Re: Kaveri & aero-engine discussion

Postby shiv » 13 Mar 2017 07:29

kapilrdave wrote:I have a question which could well be the stupidest question asked on Kaveri, but I couldn't resist the curiosity.

For high altitude tests why can't we use heavy choppers (say Chinook) to lift it along with fuel to high altitude? Use multiple choppers if required.


It has to show that it can fly when fixed in an aircraft and not just sitting static and unmoving on the ground. Lots of things keep happening in the air - the intakes change position, the air speed temperature and pressure changes, the attitude and fuel flow characteristics change and each of these could affect the engine performance.

srai
BRF Oldie
Posts: 3422
Joined: 23 Oct 2001 11:31

Re: Kaveri & aero-engine discussion

Postby srai » 13 Mar 2017 11:31

Aren't there any "wind-tunnel with altitude simulation and pressure/flow variation" type of platform for testing aero-engines?

Singha
BRF Oldie
Posts: 58784
Joined: 13 Aug 2004 19:42
Location: X,L,S,VHF band radars fully on

Re: Kaveri & aero-engine discussion

Postby Singha » 13 Mar 2017 11:37

I think this was supposed to be fixed by boeing under C17 offset by not giving work but providing these new infra. this itself was a special exemption granted to the regular offset policy.

I read somewhere they sent us a 50 yr old rotten wind tunnel though which is either DOA or needs extensive work to really use. media does not want to want to offend their foreign paymasters so keeps very quiet on such issues. govt is also somewhat afraid to offend the great khan.

there are "disillusioned warriors" on brf who know all these issues swept under the rug but keep quiet as they are inside the box and cannot speak , or they are so disillusioned they dont post much anymore.

srai
BRF Oldie
Posts: 3422
Joined: 23 Oct 2001 11:31

Re: Kaveri & aero-engine discussion

Postby srai » 13 Mar 2017 13:41

^^^

:wink:

Here is what the C-17 deal was supposed to get:
...
Boeing would also meet an offset obligation comprising 30 percent of the basic cost of the 10 aircraft, which would work out to about $1 billion, the officials added. The basic cost, without the associated equipment and training costs for IAF personnel, would work out to about $3 billion, they added.

The offset obligation arises out of the Indian defence offsets guidelines that mandate the ploughing back of a part of every deal amount in India's defence industry.

"In addition to the purchase of products and services from public and private Indian defence industries, Boeing will establish a high-altitude engine test facility at the Defence Research Development Organisation (DRDO)," India's premier military technology developer, the officials said.

This facility is not available in India and will enable aeroengines to be tested within the country.

"Boeing will also establish a trisonic wind tunnel facility at DRDO to enable testing, research and development of various aerodynamic bodies," the officials added.
...



Here is a company that providers various test facilities for aeroengines:
MDS - Altitude Engine Test Facility
...


Typical Altitude Engine Test Facilities are composed of the following MDS supplied subsystems:

Compressors / Exhausters;
Air Heating System;
Air Dryer System;
Flow Measurement System;
Settling Chamber;
Bellmouth / Free Jet Nozzle;
Altitude Test Chamber;
Thrust Measurement & Calibration System;
Engine Interface Adapter Frame;
Diffuser / Exhaust Duct / Augmenter Tube;
Closed Loop Heat Exchanger;
Water Cooling System;
Mechanical Support Systems;
Fuel Flow Measurement System;
Facility Control System (PLC & Programming);
Emergency Stop System (Safety Systems);
proDAS Data Acquisition System;
Engine Control System;
Dynamic Data System (DDS);
Controls Console;
Temperature Scanning System;
Pressure Scanning System;
Vibration Measurement System;
Strain Measurement System; and
Capabilities.
...

kapilrdave
BRFite
Posts: 1524
Joined: 17 Nov 2008 13:10

Re: Kaveri & aero-engine discussion

Postby kapilrdave » 14 Mar 2017 08:41

shiv wrote:
kapilrdave wrote:I have a question which could well be the stupidest question asked on Kaveri, but I couldn't resist the curiosity.

For high altitude tests why can't we use heavy choppers (say Chinook) to lift it along with fuel to high altitude? Use multiple choppers if required.


It has to show that it can fly when fixed in an aircraft and not just sitting static and unmoving on the ground. Lots of things keep happening in the air - the intakes change position, the air speed temperature and pressure changes, the attitude and fuel flow characteristics change and each of these could affect the engine performance.

Thanks Shivji. I had even more jugadu ideas for testing different angle of intake and fuel flow using chopper :) . But yeah, I guess without required air speed it all could be meaningless.

NRao
BRF Oldie
Posts: 15604
Joined: 01 Jan 1970 05:30
Location: Illini Nation

Re: Kaveri & aero-engine discussion

Postby NRao » 14 Mar 2017 09:03

Just saying .......

Diff app, but ........

High Altitude Flight Acceptance Test of CE20 Engine Conducted Successfully

To test the Engine at flight identical conditions, High Altitude Test (HAT) facility was established at IPRC, Mahendragiri. This facility allows testing of the CE20 engine at its full area ratio in vacuum condition which otherwise would experience flow separation at sea level ambient pressures.


Can be done. Anything can be done. IF ..........

Image

shiv
BRF Oldie
Posts: 32534
Joined: 01 Jan 1970 05:30
Location: Pindliyon ka Gooda

Re: Kaveri & aero-engine discussion

Postby shiv » 14 Mar 2017 19:52

Here is one reason why pilots may need to train on a basic jet trainer to get used to jet engine control and behaviour. Some pilots will fly transports too and fly far more hours than fighter jocks
https://www.youtube.com/watch?v=Df7BrgtbA4g

Indranil
Forum Moderator
Posts: 5332
Joined: 02 Apr 2010 01:21

Re: Kaveri & aero-engine discussion

Postby Indranil » 14 Mar 2017 23:29

Kapil,

Engines are not my forte. But, I know just enough to answer your question. There are many stages in which a modern aircraft engine is tested. What you are suggesting is called a static or bench test. An engine is put on a test stand, and a "bell mouth" is added as an air intake. The engine is then tested for various power settings, environmental conditions etc. GTRE, HAL, NAL etc. have these test beds in Bangalore. Your question is, why not make one on top of a tall mountain.

This is not feasible for two reasons. Take Siachen for example, just maintaining food supplies for soldiers is a pain. And this is at 20,000 odd feet. Chinooks can barely lift its own weight at that altitude. Imagine the complexities of maintaining a jet test center there. Two, planes fly higher, much higher.

But then how about something more realistic, say Leh? While it is possible, it is not needed. Static pressure and temperature conditions can be emulated in labs even at sea level. The question is whether you are ready to spend the money to build such a facility. The West and Russians did it half a century back. But, we said, building test engines takes away funds from growing enough rice and bananas. Which is okay, but what is holding us back now? God knows.

Thankfully, as part of the C-17 purchase, we are getting an old derelict HAT facility to GTRE. At least, we can start, i.e. if the said facility can be kept operational. I have heard things that it is hard. Getting it here is fine. Keeping it running requires parts and spares which requires clearances and further imports, and further mullah.

After the static tests, there are wing tests, like what GTRE did on the flying test bed in Russia. We need one of those in India, if we are anywhere serious in designing our own engines. After that, in case of a fighter jet, it has to coupled to the inlet. An ideal inlet would modify the airflow entering the inlet to a steady airstream which provides good engine performance. However, an ideal inlet is very difficult to design. CFDs are getting there in simulating the airflow inlets, but it is not there yet. Till then there is no alternative, but to do actual testing.

Neela
BRF Oldie
Posts: 3460
Joined: 30 Jul 2004 15:05
Location: Spectator in the dossier diplomacy tennis match

Re: Kaveri & aero-engine discussion

Postby Neela » 15 Mar 2017 12:03

Just thinking aloud if testing methods below would apply to engine development and certification.

In the semiconductor industry, circuits are tested initially for nominal or typical conditions. Circuits contain components like transistors, capacitors, resistances all of which have their own behavioral models from the foundry. Once the initial conditions of the circuit is given , they are submitted together with the models of the components to a circuit simulator which simulates the provides the necessary results asked for.

The above is the first step to prove the circuit functionality. But real-world applications conditions are different. COmmercial mass market products having ICs must work in temperatures from -40C upto +125C.
Secondly,the components like transistors also have their own parameter variation in the models which affect the output. These are called corner-sections and the manufacturer provides the typical,fast,slow models for each transistor type. Likewise for resistors are capacitors which have different corner-sections as they are passive components.
A third feature of the models of components is a random variable which is inserted into some parameters of the models.

So, after the first step of proving circuit functionality in nominal conditions, two further intensive tests are undertaken.
1. Corner simulations. Here the number of corners are discrete and is a combination of corners of the components used in the circuit. So if a transistor has 3 model corners and a resistor 2, a total of 6 corners are available which are then fed to the simulator to test functionality. The company I work for makes 2$ ICs for power management and the corners are usually around 10. Companies like Intel have 125 - 150 corners for processors circuit simulations. The corner conditions specify the extremes of the conditions the IC will work in. if it works in these conditions, then functionality is guaranteed on the extreme boundary conditions.

2. Monte Carlo simulations. Here the random variable in the models is excited and is fed to she simulator. Typically with the random variable, 1000s of simulations can be run and testing can go on infinitely. But there are mathematical formula which can be used to determine the optimal number of runs.
The results of each of the MonteCarlos simulations must fit into the specifications of the circuit.
-----------
So to the question for engine testing: Can the same be applied ? If you know the extremes of the parameters for each section of the engine, like pressure, temperature, stream velocity , you can theoretically simulate them using equations.

kapilrdave
BRFite
Posts: 1524
Joined: 17 Nov 2008 13:10

Re: Kaveri & aero-engine discussion

Postby kapilrdave » 15 Mar 2017 12:18

Thanks Indranil for taking time to respond.

So as I understand it, at least static tests can be done at service ceiling of Chinook with the required payload (WiKi says the ceiling is 20k ft without mentioning the load), may be using multiple Chinooks (?). I don't know about the ceiling with equipment load, but assuming the ceiling is at leh's level, it is still at 11000 ft. Shouldn't it take us one step forward with minimum investment and hassle?

I asked about choppers especially because maintaining a facility at high altitudes would be far more expensive and hassleful. It's probably not worth it for the progress it offers in testing. That was my initial thought.

Though, this is now only a theoretical point as Kaveri has already been tested on Russian platform so probably we don't need that one step forward.

srai
BRF Oldie
Posts: 3422
Joined: 23 Oct 2001 11:31

Re: Kaveri & aero-engine discussion

Postby srai » 15 Mar 2017 12:46

^^^
You don't need facilities at high altitudes per se. You can build altitude chambers at sea level and those can simulate 30000ft (maybe higher) plus loads of other variables, such as temperature, humidity, air mass flow etc. Won't be cheap though.

kapilrdave
BRFite
Posts: 1524
Joined: 17 Nov 2008 13:10

Re: Kaveri & aero-engine discussion

Postby kapilrdave » 15 Mar 2017 12:52

Yes, that's the proper test facility. But we don't have it and neither have it in plans. Hence the jugad I proposed.


Return to “Military Issues & History Forum”

Who is online

Users browsing this forum: Google Feedfetcher, srm, Thakur_B and 38 guests