M88 Developements for Domestic and Export markets:
First the main developement was destined to the domestic market (MN/AdA) with the steps taken by SNECMA from M88-2E1 to M88-2E4.
FROM Standard M88-2 to M88-2E4 developed from <> 1995.
New:
----Three-dimensional high-pressure (HP) compressor.
----Turbine blades.
----Blisks (one-piece blades and discs).
----Improved thermal coatings on the HP turbine.
----Advanced cooling channels for the combustion chamber.
Noticeable technological progresses:
TURBINE BLADE LIFE AUGMENTED BY A FACTOR OF THREE.
BLISKS. TOLERANCE TO HIGHER TEMPERATURES. SFC LOWERED BY UP TO 4% COMPARED TO M88-2-Evolution1.---->
FROM Standard M88-2E4 to M88-3.
New:
----LP compressor.
----Variable stator vane stage.
---->
FROM M88-3 to M88 ECO.
----HP corps.
----Combustion chamber.
---->
M88-3 VS M88 ECO.
Diameter:--------- 790mm 31.1-in VS 700mm 27.56-in.
Length:----------- 3.6 m 12-ft VS 3.5 m 12-ft.
Weight:----------- 985 kg 2,172-lb VS 897 kg 1,978-lb.
Thrust:----------- 89.9 kN 20,250-lb VS 75.5 kN 17,000-lb.
According to these figures:
M88-3 diameter is <> 90mm superior, it is 100mm longer and 88 Kg heavier than M88-2; this would add 176 Kg to Rafale away from CG.
This together with Dassault staments on their researches for weight reduction measures, lead me to conclude some time ago that the M88-3 engine wasn't totally suited to Dassault requierements and that ECO is the result of a rethink plus 10 years of further developement including ONERA technologies as used in the E4 and demonstrators (CENTOR).
http://img85.imageshack.us/img85/8642/1 ... quehn8.jpg
Source: ONERA.
SNECMA own staments on ECO Consumption and
Mass reduction targets.
The last one in English is the Press Kit - Farnborugh 2006_PDF.
NOTE The clear indication of the engine weight issue.
---->
SOURCE: Flight International DATE:03/05/95 Future thrust.
Quote: The M88-3 is "initially aimed at Sweden's need for a more powerful engine for the JAS39".
M88-3 VS RM12
Diameter:--------- 790mm 31.1-in VS 884mm 34.8 in.
Length:----------- 3.6 m 12-ft VS 4.04mm 159 in.
Weight:----------- 985 kg 2,172-lb VS 1055 kg 2325-lb.
Thrust:----------- 89.9 kN 20,250-lb VS 80.5 kN 18100-lb.
SAME YEAR, 6 MONTH LATER...
SOURCE: Flight International: DATE:22/11/95 Snecma/S Korea discuss M88 for KTX-II.
Quote: Snecma/S Korea discuss M88 for KTX-II
The company is already in talks with South Korea to offer the M88-2K, based on a proposed non-after-burning variant of the M88, the 50kN M88-2S.
Alongside projecting a family of "dry" M88s, Snecma is also looking at developing the 110 kN M88-4. This project is at the preliminary design stage, but is aimed at eventually replacing the M53K in the Mirage 2000.
Dufour says that Snecma has begun studies into the eventual re-engineing of the Mirage 2000-5, whose single M53 engine would be replaced by an M88. The company is already looking at up-rated versions of the M88 for projected higher-weight versions of the Rafale -
the M88-3 with a thrust of 90kN, and
the M88-4 with 110kN - and he sees these as being suitable for the Mirage 2000.
---->
Changes of PLANS.
After failures in the export market, SNECMA had focused on the improvements ported to the M88-2 and developed M88-3...
SOURCE:Flight International DATE:09/06/99 Snecma M88.
Quote:
Qualification of the basic Snecma M88-2 was completed in early 1996, with the first production engine delivered at the end of the same year.
The M88-2 has a thrust-to-weight ratio of 8.5, producing 11,250/16,850lb of dry/afterburner thrust (50/75kN). The engine has proved extremely reliable in flight tests to-date, by early May building up 6,200 flight hours on the Rafale, giving a total of 16,400h, including test bench running. "It is now ready for entry into operational service," says Jean Massot, M88 general manager.
Development took place under a fixed (unrevealed) price contract. The engine features state of the art technologies found also in its contemporaries, including single-crystal high-pressure turbine blades, powder metallurgy discs and full authority digital engine controls. Unrestricted operation throughout the flight envelope has been demonstrated, as has "extremely fast throttle response, low observability and multimission flexibility".
Construction is based around 21 modules, interchangeable without the need for recalibration or balancing, along with a number of line replaceable units.
Snecma is developing the M88-2 Stage 4, which has the same thrust as the standard M88-2, but incorporates improvements aimed at extending the service life of the engine and reducing fuel consumption, which Massot says "will also reduce operating costs significantly". Another benefit will be to improve the duration of the low-level penetration missions.
The changes include the introduction of three-dimensional high-pressure (HP) compressor and turbine blades, blisks (one-piece blades and discs) improved thermal coatings on the HP turbine, and advanced cooling channels for the combustion chamber. The Stage 4 development will be ready in early 2001 and the modifications will be retrofitted to the M88-2. It will power the 48 Rafales ordered in the Government's multi-year procurement plan.
A further development, the M88-3, rated at 9.5t thrust, still awaits funding, but has been benchtested on a privately funded demonstrator. "We are proposing the M88-3 to the French government for the future standard of the Rafale in the early 2000s and to prospective export customers", says Massot.
The M88-3 features a new LP compressor with higher mass flow (from 65kg/s in the -2 to 73.4kg/s). A new variable stator vane stage has been introduced, permitting the engine to operate at optimum conditions through a much wider range, reducing part-power-specific fuel consumption and providing more operational flexibility to suit the Rafale's multimission role. The development comes out of Snecma's CENTOR LP compressor research programme and from other exploratory developments carried out by Snecma in recent years. Orders for the M88-2 stand at 42 engines, plus modules and spares, with a further order for 96 units (for the 48 Rafales) expected at the Paris air show.
with the first production engine delivered at the end of the same year.
Apparently, between 03/05/95 and 09/06/99 M88-3 had seen its thrust augmented by 0.5 kN.
After the lack of interest from AdA/MN, the whole demonstrator programme was changed again and partialy taken under DGA financing to fit the French customers requierements for a yet cheaper and more effiscient solution (ECO).
From my SNECMA archive folder...
(rules)
