I woul request you both to continue discussing, because (at least) I get to get a crash course in this. I don't understand screech at all.agupta wrote: Anyways my last on this topic.
Kaveri & Aero-Engine: News & Discussion
Re: Kaveri & Aero-Engine: News & Discussion
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Re: Kaveri & Aero-Engine: News & Discussion
In depth and full-flavoured detail on SCREECH (from Newfoundland).
Also was wondering... Just as golf balls are dimpled which makes them fly further than they would otherwise, AND just as certain metal finishes that produce a sputtered or shot-blasted surface texture that is rough and uneven... MIGHT the solution to screech be hidden in the chaos of a similar "surface imperfection"?
Has this parameter been tested for, during Kaveri R&D?
Furthermore, insofar as the screech problem adds unwanted temperatures and vibrations/stresses to an engine; to what extent can these problems be mitigated with the adoption of silicon carbide ceramics in lieu of metals for rotating hot parts? These non-metallic materials are not only lighter and will spin faster; but they're stiffer and remain so up to much higher peak temperatures, than do their metal analogues.
Any insight into the use of ceramic matrix composites in the Kaveri would be of great interest to me. TIA
ALTERNATIVELY, the LCA Tejas should be fitted with India-made M88s that will power the Rafales also. Imagine the cost-savings if both platforms could support quick-swapping-out of SNECMA M88 engines; with Rafales loading two and Tejas loading one M88 powerplant.
The cost savings would be considerable; and operating this way could improve uptime/serviceability which would otherwise be constrained by the numbers of platforms. By holding an excess number of spare engines and making quick work of swapping them out all the time; platform availability would certainly improve.
Just sayin'.....
Also was wondering... Just as golf balls are dimpled which makes them fly further than they would otherwise, AND just as certain metal finishes that produce a sputtered or shot-blasted surface texture that is rough and uneven... MIGHT the solution to screech be hidden in the chaos of a similar "surface imperfection"?
Has this parameter been tested for, during Kaveri R&D?
Furthermore, insofar as the screech problem adds unwanted temperatures and vibrations/stresses to an engine; to what extent can these problems be mitigated with the adoption of silicon carbide ceramics in lieu of metals for rotating hot parts? These non-metallic materials are not only lighter and will spin faster; but they're stiffer and remain so up to much higher peak temperatures, than do their metal analogues.
Any insight into the use of ceramic matrix composites in the Kaveri would be of great interest to me. TIA
ALTERNATIVELY, the LCA Tejas should be fitted with India-made M88s that will power the Rafales also. Imagine the cost-savings if both platforms could support quick-swapping-out of SNECMA M88 engines; with Rafales loading two and Tejas loading one M88 powerplant.
The cost savings would be considerable; and operating this way could improve uptime/serviceability which would otherwise be constrained by the numbers of platforms. By holding an excess number of spare engines and making quick work of swapping them out all the time; platform availability would certainly improve.
Just sayin'.....
Re: Kaveri & Aero-Engine: News & Discussion
I am never in favour of closing a perfectly fine discussion where two parties are respectfully disagreeing on technical details. These are too few these days. Keep them coming. I know I speak for JayS too.agupta wrote: Indranil - thx for the encouragement . Hope this helps to close out topic !
Re: Kaveri & Aero-Engine: News & Discussion
Food for Thought - if dimples make golf ball fly longer, why the Airplane surfaces are not dimpled to increase their range..?Ravi Karumanchiri wrote:In depth and full-flavoured detail on SCREECH (from Newfoundland).
Also was wondering... Just as golf balls are dimpled which makes them fly further than they would otherwise, AND just as certain metal finishes that produce a sputtered or shot-blasted surface texture that is rough and uneven... MIGHT the solution to screech be hidden in the chaos of a similar "surface imperfection"?
Has this parameter been tested for, during Kaveri R&D?
Furthermore, insofar as the screech problem adds unwanted temperatures and vibrations/stresses to an engine; to what extent can these problems be mitigated with the adoption of silicon carbide ceramics in lieu of metals for rotating hot parts? These non-metallic materials are not only lighter and will spin faster; but they're stiffer and remain so up to much higher peak temperatures, than do their metal analogues.
Any insight into the use of ceramic matrix composites in the Kaveri would be of great interest to me. TIA
ALTERNATIVELY, the LCA Tejas should be fitted with India-made M88s that will power the Rafales also. Imagine the cost-savings if both platforms could support quick-swapping-out of SNECMA M88 engines; with Rafales loading two and Tejas loading one M88 powerplant.
The cost savings would be considerable; and operating this way could improve uptime/serviceability which would otherwise be constrained by the numbers of platforms. By holding an excess number of spare engines and making quick work of swapping them out all the time; platform availability would certainly improve.
Just sayin'.....
Sorry couldn't resist.
Completely difference physics. They use screech liners which is plate with holes to attenuate acoustic waves. Its difficult to eliminate generation of acoustic waves as any small change in any of the myriads of factors could bring it back in some regime or the other. Its better to provide sufficient dampening capability inside the jet pipe. Screech liners do that job. Similar acoustic liners are seen on the Fan side of turbofan as well, in in some other places in the engine.
Screech can seriously damage the rear side of the engine and the damage could be catastrophic. Any change in rotatives is not going to mitigate this issue.
I have seen couple of GTRE paper talking about CMCs, but then everyone has been talking about it for decades. It was predicted TET would reach 2500K with CMCs constituting all HPT by year 2000. We are still far from it, anywhere in the world. I have not come across any serious work in CMC from Indian orgs so far, which doesn't mean there isn't any. Just that I don't know, and I don't know much frankly. I just discovered there exists a lab called ARCI. Never heard of it before even though they have been working in some Jet engine related technologies for quite some time.
M88 actually produces less power than even F404.
Re: Kaveri & Aero-Engine: News & Discussion
I think you are talking about the final effect and I am talking about the origin of the acoustic waves. I have not denied that A/B generated acoustic waves would not result in jet screech, I just said I am not sure, they will always be able to produce strong enough instabilities. What I have been trying to say is, I think there are two distinct and unrelated sources that could produce screech - One is the A/B combustion instability and another is the instability in the jets either induced by the factors like nozzle geometry or the inherent flow instabilities in the jet itself.agupta wrote:JayS:JayS wrote:Overview of Gas Turbine Augmentor Design, operation
And Combustion Oscillation
https://engineering.purdue.edu/AAECours ... r%20Review
With all humility, this exercise demonstrates some of the risks of insufficiently deep google-search-and-read "learning". I can't explain why Google's first references returned are not very good for a first understanding - but that's my opinion.
But even in this one, E.g., You are quoting a passage on Page 8. On Page 3 specifically after the 3rd time the word screech shows up, and multiple times before in the first few pages, its clear that the reference is for military supersonic jet flows; see the link to "converging-diverging" nozzles - as u well know, those are for supersonic flows.
When the paper describes the nozzle throat as acoustically closed (See write up on Page 12), its a reference to the throat being sonic which means downstream of that (unless its perfectly expanded) you will see shock cells - and that's why screech is considered a subset of supersonic jet noise phenomena
I get what you are saying - that the Kaveri issue seems to be driven by afterburner combustion instabilities; all I am pointing out is that its NOT an EITHER/OR situation... its an "IN" situation, screech due to combustion instabilities IN a supersonic (afterburner operational) jet flow
Indranil - thx for the encouragement . Hope this helps to close out topic !
Please tell me, is following situation possible..?
1. There is enough dampening built in the jet pipe and the A/B is well design, enough not to produce strong acoustic waves of high frequency, and whatever is produced is well attenuated by the screech liner. But we still have screech in the supersonic under expanded jet outside the nozzle exit (on second thought I realized at least some acoustic waves should be able to travel downstream, but no acoustic waves from outside can come in as the flow becomes supersonic beyond the throat), where due to instabilities in the shock structure produces acoustic waves which develop feedback loop with the thin shear layer near the nozzle exit generating further instabilities and forming a close loop and eventually giving rise to screech.
2. A/B design is bad or dampening in the jet pipe is not enough to attenuate produced acoustic waves from combustion instabilities. The waves start reflecting bak and forth in the jet pipe producing organ effect. They would form a feedback loop with the A/B HW and start resonating at certain high frequency. The pressure fluctuations produced by these waves eventually will damage the screech liner, the A/B and the jet pipe due to high cycle fatigue. No some of these waves are escaping thru the nozzle throat and producing instability in the exhaust jet which is under expanded and that leads to the feedback loop and jet screech like described above.
Re: Kaveri & Aero-Engine: News & Discussion
DRDO 110 kN Engine Plan, Puzzles adding-up
Re: Kaveri & Aero-Engine: News & Discussion
India, France to hold talks on defence buys today.
Of much greater significance and far more ambitious is a new India-France project to co-develop and co-build a next generation jet engine for use by India. The lead French defence company in the reckoning here is Safran. There is little clarity on how this will be developed in India, including agencies and companies to be involved. What is clear is that the project has been nicknamed INFRA. Modi may have been hinting at this when he said after his meeting with Macron here that India and France were building INFRA in several sectors.
If it happens, this would be momentous — there aren’t that many companies in the world that can build jet engines. If India does achieve the feat, it would go a long way in giving the country autonomy in defence purchases.
It is rumoured that the outgoing French ambassador to India, Alexander Ziegler may be joining Safran, making negotiations much less problematic. This kind of movement is fairly common among envoys who have served in India where they get get snapped up by the private sector to help navigate the opaque Indian system.
Re: Kaveri & Aero-Engine: News & Discussion
An interesting post from a poster on the f-16.net forum discussing the screech phenomenon encountered during development of the PW-f135 engine for the F-35.
If this analysis is accurate, it will account for the offer made by Safran to just replace the Kaveri core as opposed to re-designing Kaveri.Screech occurs when the pressure fluctuations due to combustion process couple, mechanically, with the natural acoustics of a structure. it is not limited to afterburners. It is seen in main burners of aircraft engines and aeroderivative engines, boilers in steel plants/power plants, etc., etc..
Screech is particulary dangerous in aferburners due to the high level of heat release which occurs over a realtively short length and the, generally, axis-symetric round tailpipe (like an organ pipe).
The air is NEVER flowing at Mach 3 inside the engine. In fact, the flow is completely subsonic until after the throat plane in the exhaust nozzle. For the JSF, the gases will never exit the nozzle anywhere near Mach 3. The maximum Mach Number for the JSF on the envelope is significantly lower than 2.0. Thus, the gases will EXIT the aircraft at Mach numbers lower than 2. Yes, temperatures can be very high at Max AB (3500R potentially, locally), but the stream will be even much lower than Mach 1 upstream of the nozzle throat.
Though true that, SOMETIMES, fueling adjustments can/MAY eliminate/minimize various screech modes under specific circumstances, screech often is caused by an aero-design that has NUMEROUS inadequacies that RESULT in screech from the outset.
Though PW may CLAIM they have a "fix", I find that disengenuous, at best based onb my own experiences with this issue. Most likely, like they often do, they will bob and weave and minimize the issue to get thru development. In the end, SOLVING the problem will involve, most likely, a significant design change, which often is at odds with low observable requirements.
I have been in the engine business a long time. I have NEVER heard of a "simple" screech fix, once the problem is present in a significant magnitude.
In fact, I am unaware of an afterburner anywhere in the past that has NOT had SOME sort of acoustics issues---minor, or, god-forbid, major. If someone makes that claim, they are uninformed, or outright lying. The problem may be fixed, or desinged out in the end, but not before LOADS of development testing is paid for --- assuming the problem was there to begin with.
Afterburning Turbojets are more suceptible to the problem than turbofans, for reasons I choose not to get into here.
To those in the business and knowledgable of this issue, they would have to agree that there are no screech experts, only victims.
IF anyone honestly believes PW has a *simple* fix, I have some swamp land I can sell you in Louisiana. I'm not saying they CAN'T fix it... in the end they must... it will just cost us taxpayers boat loads of more money than planned.
just my $0.05.
Last edited by ldev on 29 Aug 2019 22:59, edited 1 time in total.
Re: Kaveri & Aero-Engine: News & Discussion
For Safran to actually jointly design a clean sheet engine with DRDO/GTRE they will not settle for Euro 250 MM or Euro 750 MM, more like Euro 25-30 Billion. That will mean India placing an order for as many or more Rafales than the Armee del Air has. At last count they have placed orders for 180 Rafales.Vips wrote:India, France to hold talks on defence buys today.
Of much greater significance and far more ambitious is a new India-France project to co-develop and co-build a next generation jet engine for use by India. The lead French defence company in the reckoning here is Safran. There is little clarity on how this will be developed in India, including agencies and companies to be involved. What is clear is that the project has been nicknamed INFRA. Modi may have been hinting at this when he said after his meeting with Macron here that India and France were building INFRA in several sectors.
If it happens, this would be momentous — there aren’t that many companies in the world that can build jet engines. If India does achieve the feat, it would go a long way in giving the country autonomy in defence purchases.
It is rumoured that the outgoing French ambassador to India, Alexander Ziegler may be joining Safran, making negotiations much less problematic. This kind of movement is fairly common among envoys who have served in India where they get get snapped up by the private sector to help navigate the opaque Indian system.
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Re: Kaveri & Aero-Engine: News & Discussion
Rumours are true after all...
https://twitter.com/ANI/status/1167144345620770816?s=19
https://twitter.com/ANI/status/1167144345620770816?s=19
Alexandre Ziegler, outgoing ambassador of France to India, has been named Safran's Senior Executive Vice President, International&Public Affairs, effective Sept 2.
Safran is an international high-technology group, operating in aircraft propulsion&equipment, space&defense markets
Re: Kaveri & Aero-Engine: News & Discussion
OH.MY.GOODNESS
Re: Kaveri & Aero-Engine: News & Discussion
So long as the ambassador is a Safran employee, it means that some deal is cooking or under negotiation with Delhi babudom. The day he quits or is fired we will know that a deal is not happening.
Re: Kaveri & Aero-Engine: News & Discussion
caveat?Rakesh wrote:OH.MY.GOODNESS
This kind of movement is fairly common among envoys who have served in India where they get get snapped up by the private sector to help navigate the opaque Indian system.
Re: Kaveri & Aero-Engine: News & Discussion
Ukrainian Aero-Engine mfg company up for sale.
Re: Kaveri & Aero-Engine: News & Discussion
I tweeted following stuff few days back.Rakesh wrote:DRDO 110 kN Engine Plan, Puzzles adding-up
Tender from HAL for outsourcing of Single Crystal Blade castings for HPT and LPT. Interesting. My best guess is this is for Adour 871 engines which power IAF's Hawk AJT fleet.
Not the first tender from HAL related to Single Crystal Blades. There was one similar tender for SCB, which I suppose meant for HPT of HTSE-1200 few years back and then a follow up tender for TBC coatings for the same.
And interestingly, GTRE has floated tender for machining and TBC quoting for SC blades and vanes meant for HP Turbine early 2019. Which engine it is meant for exactly, is anyone's guess. Kaveri engine as of now is known to be using DS blades only.
Even more interestingly, GTRE is looking for 3D printed HPT Nozzle Guide Vanes out of In718 using DMLS technology.
In Single Crystal Blade technology, the investment casting of SC is one piece of puzzle. From stock casting to final blade needs two more critical technologies
1. Laser drilling for cooling holes 2. Thermal Barrier Coating (TBC). While DMRL has been making SCB castings for a decade now, we lacked these key technologies. But it looks like some steady progress is happening on TBC at least. DMRL indicated preliminary success in
Electron Beam Physical Vapour Deposition (EBPVD) based Yttrium Stabilized Zirconium 7YSZ coating in 2017 (this is the cutting edge tech). Now, in 2019 they are looking to estb a pilot facility for EBPVD based TBC application. ARCI also working in EBPVD and seems to have made good
progress. It is likely that ARCI was the one which did TBC for HAL's HTSE-1200 HPT blades and vanes. Whether DMRL is following separate path or its in collabaration with ARCI is not clear. But definitely steady progress on TBC technology. It seems multiple instances of tech dev
is happening in key technology areas like SCB, TBC, Composites and so on. Much is going on in the background, but real test is to productionise and operationalise the technologies. We can definitely develop all those "super-secret" technologies given proper push from the top.
Re: Kaveri & Aero-Engine: News & Discussion
What I meant in #2 is there is, screech phenomenon going on in the exhaust jet (what we understand by "Jet screech"), and at the same time, the organ pipe effect going inside the jet pipe with acoustic waves bouncing back and forth in the jet pipe (both originated from the Combustion in AB of coarse) which damage the internal HW such as A/B or Screech liner eventually.agupta wrote:JayS wrote: Please tell me, is following situation possible..?
1. There is enough dampening built in the jet pipe and the A/B is well design, enough not to produce strong acoustic waves of high frequency, and whatever is produced is well attenuated by the screech liner. But we still have screech in the supersonic under expanded jet outside the nozzle exit (on second thought I realized at least some acoustic waves should be able to travel downstream, but no acoustic waves from outside can come in as the flow becomes supersonic beyond the throat), where due to instabilities in the shock structure produces acoustic waves which develop feedback loop with the thin shear layer near the nozzle exit generating further instabilities and forming a close loop and eventually giving rise to screech.
2. A/B design is bad or dampening in the jet pipe is not enough to attenuate produced acoustic waves from combustion instabilities. The waves start reflecting bak and forth in the jet pipe producing organ effect. They would form a feedback loop with the A/B HW and start resonating at certain high frequency. The pressure fluctuations produced by these waves eventually will damage the screech liner, the A/B and the jet pipe due to high cycle fatigue. No some of these waves are escaping thru the nozzle throat and producing instability in the exhaust jet which is under expanded and that leads to the feedback loop and jet screech like described above.
Specific answers
#1 Yes... we can still have screech even if A/B combustion dynamics are damped if there are alternate sources/triggers e.g., the sharp lip can create one.
#2. I didn't understand this one.
I think you're thinking there are different (competing) sources... one in the shock-cell region and one (or more) elsewhere. Not so... its one coupled phenomena.
The text posted by Idev is interesting.
Re: Kaveri & Aero-Engine: News & Discussion
USA is trying to prevent sale of Ukrainian Engine make Motor Sich to Chain. Should India throw its hat in the ring?
https://www.rt.com/news/467345-ukraine- ... na-bolton/
https://www.rt.com/news/467345-ukraine- ... na-bolton/
Re: Kaveri & Aero-Engine: News & Discussion
^^^ Engine Tech lies in the hands of a select few. Why would the select few allow a future competitor to come in?
Re: Kaveri & Aero-Engine: News & Discussion
India should buy it.Vips wrote:Ukrainian Aero-Engine mfg company up for sale.
Test US partnership.
Re: Kaveri & Aero-Engine: News & Discussion
Russia wants to build a modernized AN-124 heavy lift military freighter with all Russian parts including Russian engines. The traditional AN-124 used D-18T turbofans made by Motor-Sich, the Ukrainian engine maker which is in financial trouble. India should buy it and then buy the modernized AN-124 from Russia and equip it with a modernized version/newer development of the D-18T engine. This will mitigate the lack of heavy lift capacity because of the C-17 shutdown and expose India to this turbofan technology.ramana wrote:India should buy it.Vips wrote:Ukrainian Aero-Engine mfg company up for sale.
Test US partnership.
Ilyushin to design modernised An-124 with Russian components
Re: Kaveri & Aero-Engine: News & Discussion
because of our strong ties with russia, we have cold vibes with the ukrainians and have not encouraged them to sell arms/tech in the Indian market because of russian objections.ldev wrote:Russia wants to build a modernized AN-124 heavy lift military freighter with all Russian parts including engines. The traditional AN-124 used D-18T
turbofans made by Motor-Zich, the Ukrainian engine maker which is in financial trouble. India should buy it and then buy the modernized AN-124 from Russia and equip it with a modernized version/newer development of the engine. This will also mitigate the lack of heavy lift capacity because of the C-17 shutdown and expose India to this turbofan technology.
Ilyushin to design modernised An-124 with Russian components
It would take a lot to persuade them to accommodate us.
What guarantees would we have that those really critical employees needed to run the company technically would not leave the company once the sale is made and leave us holding a useless foreign PSU.
maybe a big arms deal with them may help to ease their reluctance, if any, in dealing with us.
Its time that we diversified away from russia as well as the US/france and maybe this is our golden chance, if we could pull it off.
The ukrainians have naval tech as well that we could really use.
re the C-17, the US actually needs more of them so in combination with the US orders and other orders from some foreign operators, the C-17 makers manage to scare up sufficient numbers of orders, they just may be willing to open up the line once again.
Last edited by chetak on 01 Sep 2019 10:13, edited 1 time in total.
Re: Kaveri & Aero-Engine: News & Discussion
For the Russians to directly deal with Ukraine is a non starter. But for India to acquire this Motor-Sich and then tell the Russians to deal with India as an intermediary is within the realm of being doable.chetak wrote: because of our strong ties with russia, we have cold vibes with the ukrainians and have not encouraged them to sell arms/tech in the Indian market because of russian objections.
It would take a lot to persuade them to accommodate us.
What guarantees would we have that those really critical employees needed to run the company technically would not leave the company once the sale is made and leave us holding a useless foreign PSU.
maybe a big arms deal with them may help to ease their reluctance, if any, in dealing with us.
Its time that we diversified away from russia as well as the US/france and maybe this is our golden chance.
The ukrainians have naval tech as well that we could really use.
The Ukrainians are totally beholden to the US so if the US gives it's nod the Ukrainians will agree to sell the company to India. To keep key employees on board you have to give them funding to develop a new generation of engines. That is in India's interest. Both to keep the employees as well as to learn the technology.
And finally work with the Russians to modernize the AN-124 but insist that for the IAF AN-124s, the engines will be sourced from the Indian owned Ukrainian Motor-Sich.
And why does India have to play catch up in this respect with China. The Chinese have already approached for the buy and were rebuffed under US pressure. Is there any department within GOI that does opportunistic global scouting for such companies?
Re: Kaveri & Aero-Engine: News & Discussion
Not to mention Chinese are churning out Y-20s equipped with Russian engines, albeit underpowered. Next gen engines will give them the required performance.
Re: Kaveri & Aero-Engine: News & Discussion
It's no more the russia of old.ldev wrote:For the Russians to directly deal with Ukraine is a non starter. But for India to acquire this Motor-Sich and then tell the Russians to deal with India as an intermediary is within the realm of being doable.chetak wrote: because of our strong ties with russia, we have cold vibes with the ukrainians and have not encouraged them to sell arms/tech in the Indian market because of russian objections.
It would take a lot to persuade them to accommodate us.
What guarantees would we have that those really critical employees needed to run the company technically would not leave the company once the sale is made and leave us holding a useless foreign PSU.
maybe a big arms deal with them may help to ease their reluctance, if any, in dealing with us.
Its time that we diversified away from russia as well as the US/france and maybe this is our golden chance.
The ukrainians have naval tech as well that we could really use.
The Ukrainians are totally beholden to the US so if the US gives it's nod the Ukrainians will agree to sell the company to India. To keep key employees on board you have to give them funding to develop a new generation of engines. That is in India's interest. Both to keep the employees as well as to learn the technology.
And finally work with the Russians to modernize the AN-124 but insist that for the IAF AN-124s, the engines will be sourced from the Indian owned Ukrainian Motor-Sich.
And why does India have to play catch up in this respect with China. The Chinese have already approached for the buy and were rebuffed under US pressure. Is there any department within GOI that does opportunistic global scouting for such companies?
any deal with ukraine will by force exclude russia and vice versa.
Dealing with these two is mutually exclusive
there is a deep enmity between the two, ukraine & russia and its a gap that we will not be able to bridge.
I wish that it were not so but there you have it.
russia blotted its copybook by invading ukraine and nothing could be worse than that for all parties concerned.
If such deals were possible at all, would we not have towed the carcass of Vikramaditya to an ukranian yard for its refit and got a much better and cheaper job done.
BTW, the US is the very last country to sell engine tech to India or allow others that it influences to do so. It
Remember what the US did with the USSR to sabotage our ISRO and the cryogenic engine project and at the time it was not very friendly with the USSR either and yet it stopped them from selling to India
Last edited by chetak on 01 Sep 2019 10:28, edited 1 time in total.
Re: Kaveri & Aero-Engine: News & Discussion
Chetak,
What about the Krivak-III frigates that India is buying from Russia? Don't they have Ukrainian gas turbines? And if so, how is that working out?
What about the Krivak-III frigates that India is buying from Russia? Don't they have Ukrainian gas turbines? And if so, how is that working out?
Re: Kaveri & Aero-Engine: News & Discussion
You may well be right there Idev ji but I am not clued up enough on the Krivak-III frigates to comment.ldev wrote:Chetak,
What about the Krivak-III frigates that India is buying from Russia? Don't they have Ukrainian gas turbines? And if so, how is that working out?
apologies as I have no details except as below
per wiki
Power plant
The Talwars features the Zorya designed and Mashproekt (Ukraine) manufactured M7N.1E gas turbine plant which comprises two DS-71 cruise turbines and two DT-59 boost turbines in two engine rooms. The cruising component consists of two DS-71 gas-turbine engines, each rated at 9,000 horsepower (6,700 kW) in forward running, and 1,500 hp (1,100 kW) in reverse. Two cruising RO63 two-speed gearboxes and one cruising R1063 auxiliary gearbox which makes it possible to use any of the cruising engines to drive both propeller shafts. A boost component with two DT-59.1 gas-turbine engines, each rated at 19,500 hp (14,500 kW) forward running, 4,500 hp (3,400 kW) in reverse and two RO58 single-speed reduction gearboxes. The four gas turbines are mounted on isolated cradles which minimize their contact with the hull and thereby considerably reduce the transmission of her vibration and sound.[4][8]
Last edited by chetak on 01 Sep 2019 10:39, edited 1 time in total.
Re: Kaveri & Aero-Engine: News & Discussion
I think Ukraine agreed to supply the gas turbines to India but would not send them to Russia, something like that.chetak wrote:You may well be right there Idev ji but I am not clued up enough on the Krivak-III frigates to comment. apologiesldev wrote:Chetak,
What about the Krivak-III frigates that India is buying from Russia? Don't they have Ukrainian gas turbines? And if so, how is that working out?
For the purchase of Motor-Sich by India the pivotal vote is the US. Anyway, nothing ventured, nothing gained.
Re: Kaveri & Aero-Engine: News & Discussion
I agree with what you say.ldev wrote:I think Ukraine agreed to supply the gas turbines to India but would not send them to Russia, something like that.chetak wrote:
You may well be right there Idev ji but I am not clued up enough on the Krivak-III frigates to comment. apologies
For the purchase of Motor-Sich by India the pivotal vote is the US. Anyway, nothing ventured, nothing gained.
we need this company badly but it looks like others are aware of it and maybe actively blocking it.
Modi hai to mumkin hai.
Let's see.
why not tweet to the PMO directly on this company.
It is just like you said, nothing ventured, nothing gained.
Re: Kaveri & Aero-Engine: News & Discussion
Now this is really really really intriguing, to say the least.JayS wrote:
I tweeted following stuff few days back.
Tender from HAL for outsourcing of Single Crystal Blade castings for HPT and LPT. Interesting. My best guess is this is for Adour 871 engines which power IAF's Hawk AJT fleet.
<snip>
Even more interestingly, GTRE is looking for 3D printed HPT Nozzle Guide Vanes out of In718 using DMLS technology.
<snip>
Normally (and contrary to popular belief), HPT Vanes are the ones who gets to deal with the raw TeT-level-heated gases (so for Kaveri HPT vanes it would be 1455deg C) - the HPT blades gets to deal with lower temp levels as there'll be some 7-8% temp drop across the HPT vanes itself.
And in the HPT rotor, the blade tip gets to deal with the highest temp levels (after the temp drop across HPT vanes), followed by the rest of the blade and finally to "low" 800-900 deg C levels in the disk.
Trouble of course is, HPT Vanes are notoriously difficult to cast - due to their larger sized geometry (compared to the blades, for example) etc - all engine makers struggle with DS/SC casting of HPT vanes and GTRE/DMRL were no exception. Most difficult aspect of course is designing and implementing various internal cooling channels etc in the vane casting dies, even before one talks about Vacuum Investment Casting etc.
Now doing away casted vanes should, and that's my hypothesis, mean the following:
Maturing of LZ-YSZ bilayer TBC tech - so GTRE/DMRL are ok with a poly crystalline application via 3-D printed HPT Vane and then applying a "thick" LZ-YSZ bilayer TBC on it, to "protect" the substrate metal.
And being a stator, they will get enough headroom wrt the "thickness" of the bi-layer TBC application etc as, unlike a rotor, the physical forces that compounds the spalding-effect to kick-in would be very less.
Pls remember that unlike 7-8YSZ TBC (which allows max 1200 deg C levels of ambient temp, before micro-structural issues starts cracking the TBC application itself), the LSZ outer coating would theoretically allow the ambient temp to go upto as high as 1800-1900 deg C etc.
There would be definitely some weight saving and may be, and more importantly, will allow higher TeT levels to come into play (of course the rotor HPT blades also need to graduate to maybe SC casted levels to handle higher temps etc).
Very interesting indeed - now, if only some paanwala confirmation were there.
Re: Kaveri & Aero-Engine: News & Discussion
it's not the cost of the enginesArjunPandit wrote:should be because of amortization over 1000 engines and no design/ip inputsGyan wrote:GE 414 Engine is only USD 5 Million, how come Jaguar upgrade engineering be is USD 13 Million each?
PS: 1500 engine was delivered in 2015
it's the state dept version of marketing 101 combined with really third grade ameriki politics.
they will soon pitch their own aircraft to replace the jag
Re: Kaveri & Aero-Engine: News & Discussion
In the meanwhile take a gander at this. no wonder that the hans are bidding for the ukrainian engine company
twitter --->
twitter --->
Pakistan refuses Chinese engines in China’s JF-17 fighters#Pakistan refuses #Chinese engines in China’s JF-17 fighters - Thanks, but no thanks #China, only #Russian engines accepted
Pakistan refuses Chinese engines in China’s JF-17 fighters
CRAIG HILL ⋅ SEPTEMBER 1, 2019
As the JF-17 is one of China’s “clean slate” designs, this bodes well for the reliability characteristics of the current generation of Chinese aircraft.
However, the JF-17 still uses a Russian engine, and the Pakistan Air Force rejected offers to use Chinese engines in their JF-17s in 2015. Engines remain a critical weakness in the Chinese aerospace industry.
The 2019 India-Pakistan border skirmish resulted in major shake-ups within the Indian Air Force (IAF).
The most accepted narrative, that of a loss of an IAF MiG-21 Bison to no losses of the Pakistan Air Force bodes poorly for the IAF. But interestingly, according to a July interview, the skirmish marked one of the first “hot” use of Pakistan’s new Chinese JF-17 “Thunder” fighters.
The JF-17 is a relatively new single-engine fighter, meant to compete against other light fighters like the F-16, Gripen, and MiG-29 for export contracts. As the Pakistan Air Force (PAF) is the only large user, most solid information about the aircraft is from Chinese marketing documents. But the July interview gives one pilot’s opinion on how the JF-17 stacks up against most common adversaries, from Sukhois to F-16s.
The extent of the JF-17’s “hot” usage following the border skirmish was in patrols near the border. In some incidents, the pilot said that during these patrols, he was getting radar lock-on Su-30MKIs at ranges in excess of 100 kilometers.
However, this doesn’t mean that a JF-17 could kill with a missile at that range. The JF-17’s primary beyond-visual-range (BVR) armament is the PL-12 missile, which is still undergoing integration (as of February 2019). During the actual border air skirmish, PAF F-16s lobbed AIM-120C-5 AMRAAM missiles at similar ranges, which forced IAF aircraft to go defensive to dodge the missiles, but no kills were scored. As the PL-12 is said to have a similar range to the AMRAAM, it’s likely that its kinematic performance at range is similar, and it too wouldn’t be able to score a kill.
But if the JF-17 allows the pilot to “lob” a missile at planes at such ranges, it still might be a step ahead of the IAF’s Su-30MKIs. According to an NDTV report, the Russian R-77 missiles cannot engage targets past 80 km.
Despite the Su-30’s missile limitations, the JF-17 pilot said that the Su-30 was one of the most formidable threats the PAF faces. This is likely due to the strong engines and maneuvering capability of the Su-30, which allows it to recover energy quickly after maneuvering and makes it hard to shoot down in a within visual range (WVR) engagement.
Interestingly, the pilot then goes onto state that he’s not that afraid of the Su-30 because he’s trained against F-16s with AMRAAMs, which he thinks is a far superior missile. The pilot also states that the MICA on the Mirage is also a significant threat.
This suggests that the pilot probably thinks that the fight will be largely decided, or largely influenced by the BVR stage of the engagement and that the JF-17’s capabilities in that arena are competitive to the F-16 and Mirage. However, the pilot does say that the JF-17’s limited BVR loadout is its main weakness, as most models of the JF-17 can only carry four BVR missiles, compared to the Su-30MKI which can carry eight or more.
The pilot also gives good marks to the JF-17 for reliability, flight characteristics, and maintenance. As the JF-17 is one of China’s “clean slate” designs, this bodes well for the reliability characteristics of the current generation of Chinese aircraft. However, the JF-17 still uses a Russian engine, and the PAF rejected offers to use Chinese engines in their JF-17s in 2015. Engines remain a critical weakness in the Chinese aerospace industry.
Re: Kaveri & Aero-Engine: News & Discussion
^^^ And the RD-33/93 itself is a pretty unreliable engine which we know from our own experience on the MiG-29s. You can also see anything powered by it from miles away because it smokes like chimney. lol
The truth is quality engines reside only in less than a handful of Western nations. But kudos to anyone who can get one to power a jet, it is arcane art of the highest order.
The truth is quality engines reside only in less than a handful of Western nations. But kudos to anyone who can get one to power a jet, it is arcane art of the highest order.
Re: Kaveri & Aero-Engine: News & Discussion
you live with what you have and what you can get or to be more truthful, what you are allowed to get by the goras.chola wrote:^^^ And the RD-33/93 itself is a pretty unreliable engine which we know from our own experience on the MiG-29s. You can also see anything powered by it from miles away because it smokes like chimney. lol
The truth is quality engines reside only in less than a handful of Western nations. But kudos to anyone who can get one to power a jet, it is arcane art of the highest order.
nothing much happening in the country on this front.
and when you boast roughly half a trillion dollars in FE reserves, a booming economy and whatnot, you will pay deluxe prices.
Re: Kaveri & Aero-Engine: News & Discussion
Even our P-15A and P-15B destroyers use the Zorya turbines. So the Ukrainians aren't averse to doing direct deals with us still. Thank goodness Zorya-Mashproekt is state owned and not up for sale (yet) unlike Motor Sich. If the Chinese bought that we would be in a soup to put it lightly.chetak wrote: You may well be right there Idev ji but I am not clued up enough on the Krivak-III frigates to comment.Power plant
The Talwars features the Zorya designed and Mashproekt (Ukraine) manufactured M7N.1E gas turbine plant which comprises two DS-71 cruise turbines and two DT-59 boost turbines in two engine rooms.
Re: Kaveri & Aero-Engine: News & Discussion
Updates on Engine programs from HAL AR 2018-19
25 KN Hindustan Turbofan Engine (HTFE-25)
Design and development of a 25kN thrust class turbofan
engine, which can be used on Basic/ Advanced military
trainers, on small business jets and also large UAV
applications is under progress. The engine can be
used on a 5-ton weight class aircraft in single engine
configuration and on aircraft of up to 9-ton weight class
with twin-engine configuration. Two core engines have
been produced so far and are undergoing development
trials. So far 339 runs have been completed on Core-1
and Core-2 engines, of which 96 runs were completed in
2018-19. HTFE-25 was successfully completed cold light
up at 14°C with spark igniters and achieving 100 per cent
max speed with and without IGV modulation. HTFE-25
engine was also successfully tested with a Technology
demonstrator of Servo based Fuel Measuring Unit (FMU).
The Company has taken up the design and development
of ‘Afterburner Technology’ for HTFE-25 aero engine. The
afterburner module was mounted on the PTAE engine
followed by a successful demonstration of the basic
afterburner technology using a fixed area propelling
nozzle for HTFE-25 engine, in March, 2019.
Interesting that it mentions DS blades while no mention of SCB. HTSE is supposed to have uncooled SCB as per its brochure. So question is whether these DS blades are for LPT or stop-gap for HPT itself..? We know that HAL has had tenders out for SCB blades and TBC coating for many years now. Difficult to connect dots here.The 1200KW Turbo shaft engine would be used as
power plant for 3 to 6-ton category helicopters. One
technology demonstrator of HTSE-1200 engine was
built and is currently under testing. Sea level testing was
conducted in DefExpo-2018 and a maximum speed of
76 per cent of engine has been achieved.
Technology demonstrators of Effusion Cooled
Combustor and High Efficiency Compressor were
developed and built for HTSE-1200 engine and
successfully tested on the engine. Directionally
Solidified Gas Generator (GG) Turbine blades were also
successfully developed for the engine. So far 250 runs
have been completed successfully.
Once certified, the above engine programmes promise
self-reliance in the critical field of aero engines and
availability of core engine technological capabilities
within the country.
Re: Kaveri & Aero-Engine: News & Discussion
The afterburner development for HTFE is also new. I would love to see what a modified Hawki powered by such an engine can do.
Re: Kaveri & Aero-Engine: News & Discussion
JayS, Please try to develop a milestone chart for the HTFE25.
List tasks
Engine Design
Engine prototype
Testing Core I & II
Cold Light up
FMU
Reheat
PTAE Demo
HTFE mating
Draw a bar chart.
Put a few inverted triangles to designate achievement.
And fill in the triangles for task completed.
--- Does Jaguar come under 9 ton class aircraft?
List tasks
Engine Design
Engine prototype
Testing Core I & II
Cold Light up
FMU
Reheat
PTAE Demo
HTFE mating
Draw a bar chart.
Put a few inverted triangles to designate achievement.
And fill in the triangles for task completed.
--- Does Jaguar come under 9 ton class aircraft?
Re: Kaveri & Aero-Engine: News & Discussion
Nope. MTOW of Jaguar is 15.7 tonne as per wiki.ramana wrote: --- Does Jaguar come under 9 ton class aircraft?
Re: Kaveri & Aero-Engine: News & Discussion
^^^ HTFE-25 is non-AB. With AB, thrust will be 35-40kN and will be suitable for Jaguar. Adour is ~27kN dry and ~37.5kN wet. Question is whether they will develop AB version in time. As of now both HTFE-25 and AB are just protos.