LEAP: greener, more efficient

In its version* intended for the C919 of the Chinese aircraft manufacturer Comac, similarly for the one that will power the Airbus A320neo, the LEAP engine meets crucial economic and environmental challenges.

Chosen by Comac, at the end of 2009, as the sole Western source of engines for the C919, and a year later by Airbus as the engine option for the A320neo, LEAP (Leading Edge Aviation Propulsion) specifically addresses the current needs of aircraft manufacturers and their clients. As fuel represents an increasing share of direct operating costs (up from 40 to 60% over the last few years), reducing consumption is indeed the number one goal for operators. Propulsion is now the main economic instrument for reducing consumption. As an answer to this problem, LEAP provides the aviation industry with a more economical as well as environmentally friendly solution, while maintaining the high level of reliability on which CFM's reputation is based. Compared to CFM56 Tech Insertion, which in 2007 became the configuration of the CFM56-7B and CFM56-5B engines powering the Boeing 737 and Airbus A320 respectively, LEAP will reduce fuel consumption by 15%, NOx (nitrogen oxides) emissions by 50%, and noise by 15 EPNdB**.

New processes and advanced materials
The fan blades and casing, for which Safran is responsible in CFM International, use breakthrough technology applied to a fan. Developed and patented by Snecma (Safran group) this technology called "3D-RTM" significantly reduces the weight of the engine while increasing the durability of the blading. Based on the use of a 3D woven composite material combined with the RTM (Resin Transfer Molding) process, it involves injecting liquid resin between a rigid mold and counter-mold (matched die molding). The 3D and composite parts thus produced, using a processes that can be readily industrialised, are both sturdy and light. The RTM process, validated in the context of the MASCOT (Moteur à Aubes de Soufflante en COmposite Taille) programme, is one of the major technological bricks in this breakthrough.

The high-pressure (HP) body, developed and manufactured by GE as part of the "e-core" programme consists of a 10-stage high pressure compressor, with a very high compression ratio, driven by a two-stage high pressure turbine. The HP body also includes an HP advanced version of the lean and low-emission blend combustion chamber, and three-dimensional aerodynamic design blading. Another key factor: its high pressure turbine incorporating advanced technologies in terms of aerodynamics, materials and cooling.

First tests
The initial results from the HP body tests currently in progress are more than encouraging. As for the LEAP engine, the validation of these technologies continues in accordance with the development plan set by the teams at Safran and its GE partner.

* Under the name LEAP-X 1C
** EPNdB (Effective Perceived Noise Decibel): aircraft noise certification unit.

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