NAIAD demonstrates tomorrow’s nacelles

Developed by Safran company Aircelle, the NAIAD program – Nacelle Innovative and Acoustic Demonstrator – will give aircraft engines lighter, quieter nacelles. We asked Anne-Sophie Goubet, NAIAD technical manager, to explain the program’s objectives.

What exactly does NAIAD entail?
NAIAD is a demonstrator program that will enable us to develop the technologies needed for tomorrow's nacelles. Aircelle launched the program back in 2007 in conjunction with fellow Safran company Snecma, as part of joint studies to define an optimized propulsion system. The main aim of the program, 50% of which is funded by the French civil aviation directorate DGAC, is to reduce the propulsion system's weight and drag – two key factors in lowering fuel consumption and therefore CO2 and NOx emissions. It is also designed to improve the nacelle's acoustic performance, while reducing maintenance costs.

What are the most significant innovations in this program?
First, noise reduction, primarily due to the nacelle design: we optimized the joints, and also expanded the areas using acoustic linings. At the same time, this "single-piece" design, without any openings, reduced the nacelle's drag. And by using composite parts we achieved weight savings as well. Finally, instead of trap doors, engine access is provided by sliding the cowling forward, which also facilitates maintenance.

The NAIAD demonstrator was delivered to Snecma in September. What are the next steps in this program?
We just started assembling the two major parts of our nacelle, the laminar forward cowl (LFC) and one piece barrel (OPB), with Snecma's Mascot fan, which is also a demonstrator for tomorrow's technologies. We have been in constant touch with Snecma over the last few years, to ensure that the technologies and interfaces used in these two projects are compatible. In 2011, the Mascot demonstrator and the OPB will be transferred to GE's test facilities in Peebles, Ohio, where they will undergo acoustic tests. Soon after that they will be joined by another major NAIAD subassembly, the acoustically treated substitute thrust reverser, or SITA.