JayS wrote:I am told 54kN/81kN thrust is achieved. I specifically asked for wet thrust against since we know there was shortfall there. But GTRE folks were insisting that they have achieved 81kN now. Both the compressor flutter and screech issues are resolved now, if you believe them.
Hmm. That is very good news indeed. So the problems discovered during the flight test was flutter and screech huh ? Trouble is , it is precisely these kind of things for which there are no "analytical" or "CFD / Simulation" stuff possible and there is no alternative to roll up sleeves, actually build , test, fix, retest loop and for that we absolutely need hight altitude test beds. Now altitude test beds date back to pre WWII and the Brits had it, the Germans of course had it and so did the Americans. There is simply no way any country can design and build a jet engine or indeed any aero engine
without such test beds! It is amazing that we expected these folks to develop engines without ANY testing infra that is absolutely necessary (the flying tests come last , but you need the altitude test beds to debug and do spiral development to even get to that stage).
The Yak Herder is of course right. These things can be done only by actual hardware testing and experimental research . In the lack of investment in testing infra, it is indeed a wonder that the GTRE has actually managed to get this far. They better kick the baboons in the nuts and have their travel budgets approved in triplicate and laminate and pack the MTR ready to eat stuff and get frequent flyer miles for test facilities in Russian, Germany or whosoever's facilities they use.
SCB is GTRE+DMRL project. SCB with 2nd Gen alloys process is matured tech now, Industrialization of the process is remaining. Apart from making raw blades two more key things lacking are final machining of the SCB's and TBC. MIDHANI is working on this. And they are confident they can do it in 2-3yrs. Right now the blades are to be sent abroad for one or both of these two processes anyway, which is not desirable.
If you notice, Kaveri is running with max 1700K TET value. Currently its not using any SCBs, only DS blades, as per GTRE folks. There is a gap of ~200K here from the state-of-the-art.
There is huge room for growth with the current Kaveri if high temp materials become available. A higher bypass ratio (it is something like 0.16 or something, something close to 0.35 to 0.45 thereabouts, will be "civilised/respectable" like the rest) , along with (the resulting higher TET) will see both efficiency and thrust increase, and take this to close to 64 KN dry /100KN wet engine. For e.g., the plain vanilla M53, in the Mirage 2000, saw a one ton thrust increase when the materials developed for Rafale were back ported into it and hence the new M53 P2 (for the M2005 and M2009) . That said the snecma brochure says
M53 P2 has a TET of 1600K. So if they have got to 1700K , it is not bad at all.
