But, here is an interesting diagram, we now have a basic idea of temp/pressure/alloys in a Kaveri (it may have changed):
Well, that diagram looks like what that would ultimately LIKE to achieve and not what it is at present. With a overall pressure ratio of 30 and turbine entry temp of the order of 2200 C , you are looking at only single crystal blades and absolutely cutting edge cooling schemes and thermal barrier coatings in the high pressure turbine.
And yeah. That engine will be at par with the EJ200 + and GE414 and M-88-3/4in terms of technology levels. I dont think we are there now.
Vinaji, this has been discussed a few times before, that diagram is a bit misleading (maybe pre-meditated as well) - 2200dec C temp is what is attained in the combustor and not the Turbine Inlet/Entry Temp - no turbine blade exists (yet) which can handle that high temperature (except maybe the ceramic ones, but then there are no military turbine engines, that I know of, uses ceramic blades).
Also as moi, Geethji and Katareji had pointed out earlier here - from moi
(and here - from Geethji
and here - from Katareji
), to prevent melting of the turbine blades, the tertiary/dilution zone of a combuster allows the "cold" air (approx 2/3 of the volume of compressor-generated "cold air")bypassed from the combustor primary zone (PZ) and the secondary/intermediate zone, to mix and bring down the temp of the combusted gas to an acceptable/tolerable level of the turbine blades - before it hits the turbine.
The highest TET that I've heard of are for F119, which is IIRC, around 1823K (or 1550deg centigrade) or thereabouts (maybe 1600deg C, as a higher ballpark). To handle even higher temp (approx around 1900deg C or a little more) you would need Ceramic Matrix Composite (CMC)
technology, which is basically at a R&D stage worldwide (again IIRC).By contrast, the TET for kaveri is around 1426deg C.
And I think it's worth mentioning in this context that, world-wide engine development (well more precisely, the engine metallurgy devleopment) history tells us every 100-150deg C increase in TET (beyond 1300deg C) has taken approx a decade of solid R&D by the advanced nations.
Pls refer to Pg 5 (Fig. 1.5) of the ebook The Superalloys - Fundamentals and Applications, Roger C Reed
for a better understanding of the evolutionary path of the TET vs turbine metallurgy.
The path is DS -> Monocrystalline (SCB) 1st Gen -> Monocrystalline (SCB) 2nd Gen (usage of Rhenium) with internal blade cooling and TBC (1st gen) -> SCB with internal blade cooling and TBC (2nd Gen).
Long way for us to go before we start talking about 1600 deg C TET.
Also pls note 2200deg centigrade is very close to the stoichiometric temperature of "perfect" air-fuel mixture - very hard to attain in the real-world scenarios (but that's besides the point though).