In order to face the global air-traffic growing in an environmental context, strong improvements on aircraft engine are required. Consequently, the NEWAC Integrated Project contribute to these future low-emissions engines by developing new technologies and new architectures on the High Pressure (HP) parts. Among the several architectures and visions investigated within NEWAC, the Flow Controlled Core approach (SP5), leaded by Snecma, aims to develop HP compressors improvement for both Contra-Rotating Turbo Fan (CRTF) or conventional engine.

All the innovations developed under the Flow Control “banner” aim at to improving the next standard of HP compressors in term of efficiency and operability. The performance enhancement relies on innovative technologies and new design and integration approaches. Among these technologies, advanced casing treatments specifically designed for high-pressure compressor are considered. Other concepts such as casing aspiration or air injection. Aspiration is investigated both on casing walls and blades profiles where innovation is a lot higher and can lead to new perspectives. As a result of the combination of these innovative concepts with an appropriate design of the blades and vanes, a significant benefit is expected.

A 3D optimised aerodynamic of a highly loaded compressor has been designed in conjunction with new concepts incorporated at casing. A renewed compressor, including new blade and vanes and a new casings have been designed; manufactured, and assembled. Tests are now shortly ahead thanks to the involvement of many individuals, and among them the SP5 partners in this activity (ONERA, CENAERO).

[Begleittext / Subline: Multistage CFD analysis for highly efficient compressor and casing treatment ]

[Begleittext / Subline: Advanced compressor – End of assembly ]

Another concept investigated is the aspiration concept on blades profiles. Obviously, such a concept is highly prospective in term of aerodynamic but also regarding its integration in the real-engine environment. The lab-scale experiments in place at EPFL (with the support of LMFA and ONERA) have provided highly valuable results which are now deeply analysed and discussed between the partners.

[Begleittext / Subline: Aspiration concept (on endwall and profile) to control boundary-layer separation ]

Radial clearance between the blade-tip and the casing is a major parameter on compressor performance, with impact both on efficiency and stall margin. Efforts for tighter clearance are also done in the course of the SP5, thanks to the involvements of TA, SMCH, and the universities Ulg and UTBM. The rationale is to be able to run with tighter clearance on new engine and to encounter a lower clearance-opening during engine-life. An advanced numerical simulation on blade-casing contact phenomenon is now in place, while a full validation is expected from different mechanical rig-tests. In parallel, new abradable coating are developed.

Thanks to the technical and human involvement of all the partners, the SP5 is now close to many achievements with the full-scale tests shortly ahead and the integration of the results at the engine level. With many specialists and a lot of expertise involved in the SP5, I’m glad to see the SP5 sub-project running well and greatly contributing to the objectives of the NEWAC project.

Armel Touyeras

NEWAC SP5 Leader

Snecma, Safran Group

CENAERO            Centre de Recherche en Aéronautique

ONERA                 Office National d'Etudes et de Recherches Aérospatiales

EPFL                     Ecole Polytechnique Fédérale de Lausanne

ECL-LMFA            Ecole Centrale de Lyon – Laboratoire de Mécanique des Fluides et d’Accoustique

TA                           Techspace Aero, Safran Group

ULG                       Université de Liège

UTBL                     Université de Technologie de Belfort-Montbéliard

SMCH                    Sulzer Metco AG

CRTF                     Contra-Rotating Turbo Fan