I have always maintained that the assumption for the need to increase airflow by way of increasing LP turbines diameter wasn't correct on the basis that this technology was that of the M88-3 and that internal aerodynamics had been improved since 1995.
My personal opinion was that this work by SNECMA and ONERA was meant to increase M88 pressure recovery capabilties as well as overal efficiency without resizing the inlets.
As a matter of FACT: From two pre-production M88, SNECMA claimed an increase in TWR from 8.5:1 to 10.0:1 with a TET increse of 177*c in 1987.
M88-II was already running at 85 kN in 1987, pressure ratio was increased too.
M88-3 was running at 95 kN in 1995, ECO in 2006.
Considering the technologic progresses made for design and materials i conclude that there is no need for a larger L-P Turbine.
I believe that the work on the 90 kN version of ECO, based on its newly developed low-pressure turbine but also a new high-pressure core design, combined with the increase in TET will be enough to give the engine 60/90 kN without an increase in L-P turbine diameter.
I'm sure OPIT will desagree but none of his comments on the subject ever took the aerodynamic effectiveness and TET increase in account, ignoring the peripheral developement programes conducted by SNECMA and ONERA on these technologies.
He based his theory on the experiece acquiered with engine two generations older than ECO.
In this doc, we also can find the clues and confirmation of M88 superior colling and details of its design:
Double wall anular combustor with double cooling systems and airblast fuel nozzles.
Thanks to the guy who posted this doc first...Wait and see.
Quote:
The UAE is also demanding a higher thrust version of the fighter's Snecma M88 engine to suit the hot-and-high conditions prevalent in the Middle East. A test program for the new powerplant, aimed at raising thrust to 9 metric tons from 7.5 tons currently, was announced in the run-up to last week's Paris Air Show. The main focus of the program is a new high-pressure core design that will begin running in September as part of a package of improvements, known as the Pack CGP-9T, intended to reduce M88 ownership costs for the French armed forces.
A demonstrator for the low-pressure part of the engine began testing this spring. The test program would enable the higher-power version to be available within three years of contract signature, Snecma executives say.
Jun 22, 2009
Michael A. Taverna/Paris
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