Clean Sky Research Project Accelerates after Slow Start

 - June 25, 2010, 6:40 AM
European companies' work toward “greener” air transport under the Clean Sky program has taken the form of open rotor technology such as that under study by Safran subsidiary Snecma. The company displayed the mockup at the first Clean Sky conference, held in Brussels last week.

The European Union's €1.6 billion ($1.9 billion) aeronautics research effort known as Clean Sky recently has gained momentum, and officials expect to see several demonstrators running on the ground or in the air by 2014 or 2015. After a slow start in 2008-2009, the so-called joint technology initiative (JTI) is now progressing at almost nominal speed. Project leaders hope to offer timely solutions to render the next generation of aircraft more environmentally friendly; the development of brilliant technologies over a period far into the future would prove a mistake, they believe. Schedules call for the public-private partnership to end in 2017, after the European Commission and the industry each spend €800 million ($950 million) in cash and in kind, respectively.

The project centers around six “integrated technology demonstrators” (ITDs) that focus on topics such as a low-drag wing or more efficient engines. The joint undertaking, now staffed with 20, plans to launch four calls for proposals per year until 2012. They expect those efforts to bring on board more small and medium-size enterprises, until the total number of partners reaches 500.

In engines, Snecma and Rolls-Royce each continue to study contra-rotating open rotors. Snecma's work involves a direct-drive system, while Rolls-Royce works on a geared engine. How the choice gets made between the two when the time comes for flight testing, probably on an Airbus testbed, remains undetermined. Meanwhile, one of the toughest challenges will involve cutting noise by minimizing the interaction between the two rows of blades. One possibility centers on blade size. Snecma exhibited a mockup on which the first row of blades stands higher.

Some ITDs are transversal. In “Eco-design,” for example, research engineers will look for ways to reduce scrap rates. More originally, a “technology evaluator” will help determine the effectiveness of Clean Sky's technologies. The simulation tool will assess the effect of the technologies on a given day at, for instance, the airport level. Developers expect to release the first technology evaluator next year.

The first Clean Sky conference took place in Brussels on June 18, more than two years after the JTI officially came into existence in February 2008. According to executive director Eric Dautriat, “There was more to do than anticipated.” The first preliminary design reviews will take place this year.