Snecma M88
The Snecma M88 is a turbofan engine with afterburner, which was developed by Snecma for the Dassault Rafale French fighter plane. The engine provides a boost of 50 kN with a fuel consumption of 0.8 kg / h and 75 daN · kN when the afterburner ( 1.7 kg / daN · h).
History
Since 1986 has been working at the Snecma M88 engine, which was tested on the version M88 -1 from 1990 to the Rafale A and since 1996 is also available in the standard version M88 -2 available. Having a dry capacity of 50 kN and 75 kN Nachbrennerleistung it corresponds to the power class of the F404, but is smaller and lighter in order to allow the required small dimensions of the Rafale. It is a two-shaft turbofan engine with three low-pressure compressor stages, six high-pressure compressor stages, an annular combustion chamber, each a cooled single-stage high and low pressure turbine and an afterburner. The blades are manufactured monocrystalline, allowing higher operating temperatures. The M88 is the first two-shaft engine from Snecma for combat aircraft. This design increases the efficiency of the engine, but also its complexity and weight. The thrust - to-weight ratio of the engine is 5.7 without and 8.5 with afterburner, the bypass ratio is 0.3:1. The total compression is 24,5:1, the air flow rate at 65 kg / s The M88 is equipped with a redundant fully digital electronic control system ( so-called FADEC), which increases the efficiency of the engine. In order to facilitate the maintenance and replacement of individual components, the engine is built from 21 modules. The change of an entire engine can be accomplished within an hour. Furthermore, all Rafale with an APU from Micro Turbo, a subsidiary of Snecma, equipped to be used for supplying power to the ground and starting the engines.
The two M88 -2 give the Rafale at normal takeoff weight a thrust - to-weight ratio of 1.04. Since the thrust is greater than the weight, the Rafale can fly vertically with normal payload. Dassault also indicates that the Rafale is supercruise - capable with a supersonic optimized 1250 -liter auxiliary tank and four air - to-air missiles, ie without afterburner supersonic speed can reach. Since this date could not be proven and does not reach the dry thrust the values of the Euro Fighters, which is doubtful, at least with the external loads specified by Dassault.
Between 2004 and 2007, the potential for future improvements have been explored with the M88 - ECO program. One hand, the service life has been attempted to reduce the operating costs, including the extended maintenance intervals, and extended, the fuel consumption should be reduced. To achieve this, the low-pressure turbine, the high-pressure turbine has been provided with new blisks, improves, in particular, the blades are cooled and made largely of the afterburner of lighter ceramic composites. On the other hand, the output increases to about 60 kN 90 kN was dry and wet by increasing the air flow rate to 72 kg / s tested. Despite increased by about 20 % power, specific fuel consumption would remain unchanged. Each has its own prototype was built and tested for both goals. Those changes, which contribute to the reduction of operating costs, have been taken over in 2012 as M88 -4E in the series production. The increase in engine power will not be implemented. The United Arab Emirates are due to the high rate of air temperatures of the local operational environment and the correspondingly lower buoyancy have an interest in these so-called M88 -3 variant.