SpArK
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Rafale Engine
Needs versatile and powerful engine of the aircraft response to the M88-2. This completely new engine was developed specifically for the Rafale.
The M88-2 (photo Snecma)
The main characteristic of an engine operating at low altitude is above all a low specific fuel consumption. The new turbofan engine, turbofan responds to this with a high compression ratio of 24.5, and components in high yield.
By cons, an engine designed for high altitudes requires a high specific thrust, and a low dilution rate. For this, a dilution rate of 0.3, a high turbine inlet temperature of 1577 ° C and post-combution (PC) on the two flows were adopted.
Such performances were achieved thanks to new techniques include: single-piece bladed compressor disks (DAM), annular combustion chamber clean, blades and turbine nozzles HP (High Pressure) single crystal alloy and a clever cooling system disks HPC powder metallurgy (very reliable and light), ceramic coatings and composite materials for the components of nozzles and cold runner.
The motor is controlled digitally by two computers, programmed with 160 general laws, the system component "FADEC". This allows easy control, optimal, unrestricted engine throughout the flight envelope. For example, it allows both engines were started in only two minutes, and to accelerate from idle to full PCs in just three seconds. This regulation is an important factor in reducing pilot workload. But not only for the pilot: Also for the engineer because the system does not only regulate but also monitors the engine whenever possible, to identify and isolate faults, compute performance, track aging, vibration monitoring etc ... in real time!).
The launch of these engines is accomplished through the APU (Auxiliary Power Unit), which also manages the packaging of the carrier when the aircraft is on the ground.
It is interesting to note, in terms of progress, the M88 is a driver whose mass (897kg) and length (3.53 m) decreased by 45% compared to the Atar 9K50 fitted to the Mirage F1. However, its thrust / weight ratio increased 88% to $ 9.
Beyond its thrust performance and fuel economy is also an engine that's discreet. Indeed, it has all the latest technical advances to reduce its RCS, and especially its SIR (infrared signature). In most situations, the M88 does not affect the infrared signature of the aircraft.
By cons, and of course the engine is one of the first components whose development is long-planned, as it is conceived as a father.
If studies for M88-3 to 90kN and 115kN M88-4 were unsuccessful, they are re-oriented M88 ECO. As such, both engines are tested, one having already demonstrated the ability to reach 90kN (about increased air flow, imposing an air intake slightly larger), and the other aims to increase its life by 50%. The technologies developed are, among others, monocrystalline blade thermal barrier to withstand temperatures of 2100 ° C, the new controllers ... etc..
If the version with extended life interests the French armies, the version "90kN" is mainly for export for use under the equatorial temperatures and in case of non availability of tankers. That said, this version could benefit the Navy aircraft catapult very heavy (20% extra thrust would be substantial) or the Air Force as well, to provide energy for the future pod interference power.
PS: Grammatical errors from translation..
