'Morphed' engines may cut airplane noise

Washington, May 29 (ANI): In an attempt to reduce airliner noise on future planes, design engineers of a leading aeroplane firm are exploring smart engine enclosures, which can alter their shape in flight .

The cookie-cutter 'chevron' structures that cut into the rear of Boeing's 787 airliner's engine, basically lead to destructive interference by mixing the emerging hot air blasting out of the jet core with the draggy eddy currents generated as the engine bites into the airflow around the engine

This decreases the engine noise by 15 decibels when the airliner is at the airport. It gets further reduced by between 4 to 6 decibels in the back cabin.

Boeing vice-president Randy Tinseth, who announced the plans for the firm's next version of its veteran airliner, the 737, at the Royal Aeronautical Society in London on Monday, asserted that if the technology could be subtly adaptive to flight conditions it will be even better at its job.

While the 737 Max, will have static chevrons initially, when it will be launched in year 2017, that may not always be the case.

"One of the things we're looking at for the future is how airplane materials can change their characteristics as a flight progresses. And one of the things we're looking at, for example, is moving and changing the chevron shape so they optimise the noise footprint at different phases of flight," the New Scientist quoted Tinseth as saying.

The basic principle for the technique was tested by Boeing back in the year 2005.

It used a "temperature reactive alloy" which distorted the chevrons on a test 777 engine into its jet exhaust to cut down noise when the jet took off with a high thrust.

"The technology isn't here today. But we're looking for the types of materials that can do it," Tinseth added. (ANI)