30/11/2006 – First major review
On November 30, 2006, the first major review of the results of VITAL technologies took place at Snecma's Villaroche plant near Paris, bringing together all heads of the different sub-projects. SP1, which oversees the technical unity of the other sub-projects, integrated the technical design results for each of the three engine architectures and compared these results with Airbus data. The SP1 meeting checked that objectives were being met.
SP2 Result
SP2 tests new fan module concepts and measures their aero-acoustic performance and weight. Concerning aerodynamics, the Direct-drive (conventional) Turbofan design has been completed and initial tests will be performed on the ANECOM test stand (in Wildau nr Berlin, D) during the first quarter of 2008. The Contrafan (revolutionary) design has been completed too, and tests will take place on the CIAM test bench (nr Moscow, Russia) during the first half of 2007. These designs aim to reduce noise and cut CO2 emissions and preliminary performance predictions for both designs look promising.
From the mechanical standpoint, it is important to reduce fan system weight, as the above aerodynamic designs use a larger fan diameter (higher bypass ratio). For the Light Weight Direct-drive fan the geometry has been designed and the manufacturing methods selected. Production of a full-scale module has been launched, targeting mechanical tests to validate the design in the first half of 2008. Again, current predictions are that the weight reduction targets for the Fan module will be met.
SP3 Result
Design and manufacture of the highly-loaded booster stage has been completed, and the test section assembled. The concept studies for the lightweight rotor design are finished, and the other static booster applications selected. The full-scale 3-stage low-speed highly-loaded booster design has been completed, as well as the booster integration in the CIAM test bench concept studies. The scaled-down high-speed booster has passed its critical design review, and the detailed drawings have been finalized.
SP4 Result
New production technologies have been identified for the hot and cold structures in the engine’s low-pressure system. They are faster, lighter and cheaper. The OGV aerodynamic design is completed, and manufacture of the fan outlet guide vane structure for SP2 has been launched.
SP5 Result
The aim of SP5 is to increase torque density transmitted by the low-pressure shafts by 50%. Two new technologies are under study: a shaft using a metallic matrix composite material (TiMMC) and a multi-metallic shaft.
Based on preliminary material characterizations and the design review, the TiMMC approach looks very promising in terms of the weight budget. For the multi-metallic approach, a pair of materials has been identified as the ideal tradeoff between strength and temperature resistance.
SP6 Result
The ultra-high-lift aerodynamic cascade has been tested on the AVIO-Sangone rig, in 7 and 10 blade configurations. Test have been performed with and without upstream generated wakes. Test results will help improve turbulence and transition models in the CFD codes for future design purposes. The results of efficiency recovery tests for lightweight turbines show that by optimizing the design of the suction side for low Reynolds numbers, the chord can be significantly decreased. Pre-test analysis and test specifications have been developed for the ultra-low-noise 1-½ stage rig design.
SP7 Result
SP7 aims to study two major aspects of the underwing installation of VHBR engines at the aircraft level:
- Compatibility of low-noise nozzle devices to reduce jet noise without penalty due to the presence of the wing. Numerical simulations are under way, along with aeroacoustic tests which began in early 2007 at the ONERA Cepra19 wind tunnel facility.
-The possibility of reducing nacelle weight by 5% by using innovative thrust reverser concepts.
The objective is to reduce jet noise by 1dB. Today, a 0.8 dB reduction has been achieved. ONERA has already demonstrated its ability to measure and characterize the aerodynamic field around a jet using the innovative measurement technique PIV (Particle Image Velocimetry), which is key to validating the numerical simulations. Two promising thrust reverser concepts have been selected, and detailed studies are being performed by Aircelle and Shorts.